TY - GEN A1 - Dahm, Torsten A1 - Becker, Dirk A1 - Bischoff, Monika A1 - Cesca, Simone A1 - Dost, B. A1 - Fritschen, R. A1 - Hainzl, Sebastian A1 - Klose, C. D. A1 - Kuhn, D. A1 - Lasocki, S. A1 - Meier, Thomas A1 - Ohrnberger, Matthias A1 - Rivalta, Eleonora A1 - Wegler, Ulrich A1 - Husen, Stephan T1 - Recommendation for the discrimination of human-related and natural seismicity T2 - Journal of seismology N2 - Various techniques are utilized by the seismological community, extractive industries, energy and geoengineering companies to identify earthquake nucleation processes in close proximity to engineering operation points. These operations may comprise fluid extraction or injections, artificial water reservoir impoundments, open pit and deep mining, deep geothermal power generations or carbon sequestration. In this letter to the editor, we outline several lines of investigation that we suggest to follow to address the discrimination problem between natural seismicity and seismic events induced or triggered by geoengineering activities. These suggestions have been developed by a group of experts during several meetings and workshops, and we feel that their publication as a summary report is helpful for the geoscientific community. Specific investigation procedures and discrimination approaches, on which our recommendations are based, are also published in this Special Issue (SI) of Journal of Seismology. KW - Triggered seismicity KW - Induced seismicity Y1 - 2013 U6 - https://doi.org/10.1007/s10950-012-9295-6 SN - 1383-4649 VL - 17 IS - 1 SP - 197 EP - 202 PB - Springer CY - Dordrecht ER - TY - INPR A1 - Cesca, Simone A1 - Dost, Bernard A1 - Oth, Adrien T1 - Preface to the special issue "Triggered and induced seismicity: probabilities and discrimination" T2 - Journal of seismology Y1 - 2013 U6 - https://doi.org/10.1007/s10950-012-9338-z SN - 1383-4649 VL - 17 IS - 1 SP - 1 EP - 4 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Hammer, Conny A1 - Ohrnberger, Matthias A1 - Faeh, Donat T1 - Classifying seismic waveforms from scratch: a case study in the alpine environment JF - Geophysical journal international N2 - Nowadays, an increasing amount of seismic data is collected by daily observatory routines. The basic step for successfully analyzing those data is the correct detection of various event types. However, the visually scanning process is a time-consuming task. Applying standard techniques for detection like the STA/LTAtrigger still requires the manual control for classification. Here, we present a useful alternative. The incoming data stream is scanned automatically for events of interest. A stochastic classifier, called hidden Markov model, is learned for each class of interest enabling the recognition of highly variable waveforms. In contrast to other automatic techniques as neural networks or support vector machines the algorithm allows to start the classification from scratch as soon as interesting events are identified. Neither the tedious process of collecting training samples nor a time-consuming configuration of the classifier is required. An approach originally introduced for the volcanic task force action allows to learn classifier properties from a single waveform example and some hours of background recording. Besides a reduction of required workload this also enables to detect very rare events. Especially the latter feature provides a milestone point for the use of seismic devices in alpine warning systems. Furthermore, the system offers the opportunity to flag new signal classes that have not been defined before. We demonstrate the application of the classification system using a data set from the Swiss Seismological Survey achieving very high recognition rates. In detail we document all refinements of the classifier providing a step-by-step guide for the fast set up of a well-working classification system. KW - Time series analysis KW - Neural networks, fuzzy logic KW - Seismic monitoring and test-ban treaty verification KW - Early warning KW - Probability distributions Y1 - 2013 U6 - https://doi.org/10.1093/gji/ggs036 SN - 0956-540X SN - 1365-246X VL - 192 IS - 1 SP - 425 EP - 439 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Hobiger, M. A1 - Cornou, C. A1 - Wathelet, M. A1 - Di Giulio, G. A1 - Knapmeyer-Endrun, B. A1 - Renalier, F. A1 - Bard, Pierre-Yves A1 - Savvaidis, Alexandros A1 - Hailemikael, S. A1 - Le Bihan, N. A1 - Ohrnberger, Matthias A1 - Theodoulidis, N. T1 - Ground structure imaging by inversions of Rayleigh wave ellipticity sensitivity analysis and application to European strong-motion sites JF - Geophysical journal international N2 - The knowledge of the local soil structure is important for the assessment of seismic hazards. A widespread, but time-consuming technique to retrieve the parameters of the local underground is the drilling of boreholes. Another way to obtain the shear wave velocity profile at a given location is the inversion of surface wave dispersion curves. To ensure a good resolution for both superficial and deeper layers, the used dispersion curves need to cover a wide frequency range. This wide frequency range can be obtained using several arrays of seismic sensors or a single array comprising a large number of sensors. Consequently, these measurements are time-consuming. A simpler alternative is provided by the use of the ellipticity of Rayleigh waves. The frequency dependence of the ellipticity is tightly linked to the shear wave velocity profile. Furthermore, it can be measured using a single seismic sensor. As soil structures obtained by scaling of a given model exhibit the same ellipticity curve, any inversion of the ellipticity curve alone will be ambiguous. Therefore, additional measurements which fix the absolute value of the shear wave velocity profile at some points have to be included in the inversion process. Small-scale spatial autocorrelation measurements or MASW measurements can provide the needed data. Using a theoretical soil structure, we show which parts of the ellipticity curve have to be included in the inversion process to get a reliable result and which parts can be omitted. Furthermore, the use of autocorrelation or high-frequency dispersion curves will be highlighted. The resulting guidelines for inversions including ellipticity data are then applied to real data measurements collected at 14 different sites during the European NERIES project. It is found that the results are in good agreement with dispersion curve measurements. Furthermore, the method can help in identifying the mode of Rayleigh waves in dispersion curve measurements. KW - Inverse theory KW - Surface waves and free oscillations KW - Site effects KW - Computational seismology KW - Wave propagation Y1 - 2013 U6 - https://doi.org/10.1093/gji/ggs005 SN - 0956-540X VL - 192 IS - 1 SP - 207 EP - 229 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Barthold, Frauke Katrin A1 - Wiesmeier, Martin A1 - Breuer, L. A1 - Frede, Hans-Georg A1 - Wu, J. A1 - Blank, F. Benjamin T1 - Land use and climate control the spatial distribution of soil types in the grasslands of Inner Mongolia JF - Journal of arid environments N2 - The spatial distribution of soil types is controlled by a set of environmental factors such as climate, organisms, parent material and topography as well as time and space. A change of these factors will lead to a change in the spatial distribution of soil types. In this study, we use a digital soil mapping approach to improve our knowledge about major soil type distributing factors in the steppe regions of Inner Mongolia (China) which currently undergo tremendous environmental change, e.g. climate and land use change. We use Random Forests in an effort to map Reference Soil Groups according to the World Reference Base for Soil Resources (WRB) in the Xilin River catchment. We benefit from the superior prediction capabilities of RF and additional interpretive results in order to identify the major environmental factors that control spatial patterns of soil types. The nine WRB soil groups that were identified and spatially predicted for the study area are Arenosol, Calcisol, Cambisol, Chernozem, Cryosol, Gleysol, Kastanozem, Phaeozem and Regosol. Model and prediction performances of the RF model are high with an Out-of-Bag error of 51.6% for the model and a misclassification error for the predicted map of 28.9%. The main controlling factors of soil type distribution are land use, a set of topographic variables, geology and climate. However, land use and climate are of major importance and topography and geology are of minor importance. The visualizations of the predictions, the variable importance measures as result of RF and the comparisons of these with the spatial distribution of the environmental factors delivered additional, quantitative information of these controlling factors and revealed that intensively grazed areas are subjected to soil degradation. However, most of the area is still governed by natural soil forming processes which are driven by climate, topography and geology. Most importantly though, our study revealed that a shift towards warmer temperatures and lower precipitation regimes will lead to a change of the spatial distribution of RSGs towards steppe soils that store less carbon, i.e. a decrease of spatial extent of Phaeozems and an increase of spatial extent of Chernozems and Kastanozems. KW - Random Forests KW - Soil-environmental relationships KW - Steppe KW - Inner Mongolia KW - Land use change KW - Climate change Y1 - 2013 U6 - https://doi.org/10.1016/j.jaridenv.2012.08.004 SN - 0140-1963 VL - 88 IS - 1 SP - 194 EP - 205 PB - Elsevier CY - London ER - TY - JOUR A1 - Jaramillo-Vogel, David A1 - Strasser, Andre A1 - Frijia, Gianluca A1 - Spezzaferri, Silvia T1 - Neritic isotope and sedimentary records of the Eocene-Oligocene greenhouse-icehouse transition the Calcare di Nago Formation (northern Italy) in a global context JF - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences N2 - From the Middle Eocene to Early Oligocene, the Earth experienced the most significant climatic cooling of the Cenozoic era. The Eocene-Oligocene transition (EOT) represents the culmination of this climatic cooling, leading to the onset of the Antarctic glaciation and, consequently, to the beginning of the present-day icehouse world. Whereas the response of deep-sea systems to this climate transition has been widely studied, its impact on the shallow-water carbonate realm is poorly constrained. Here, the sedimentary expression of the EOT in two shallow-marine carbonate successions (Nago and San Valentino, northern Italy) belonging to the Calcare di Nago Formation is presented. The chronostratigraphic framework was constructed by integrating litho-, bio-, and isotope-stratigraphic data (C and Sr isotopes), allowing to correlate these shallow-marine successions with pelagic sections in central Italy (Massignano), Tanzania (TOP Sites 12 and 17), and the Indian Ocean (ODP Site 744). Within several sections in northern Italy, including Nago and San Valentino, a Priabonian (Late Eocene) transgression is recorded. Oxygen isotopes of ODP Site 744 show a coeval negative shift of 0.4 parts per thousand., suggesting a glacio-eustatic origin for this transgression. In the Nago and San Valentino sections, no prominent sequence boundary has been detected that would indicate a rapid sea-level drop occurring together with the positive shift in delta O-18 defining the EOT-1 cooling event. Instead, a gradual shallowing of the depositional environment is observed. At TDP Sites 12 and 17, the EOT-1 is followed by a negative shift in delta O-18 of around 0.4 parts per thousand, which correlates with a relative deepening of the environment in the studied sections and suggests a melting pulse between EOT-1 and the Oligocene isotope event 1 (Oi-1). The positive delta O-18 shift related to the Oi-1 translates in San Valentino into a change in carbonate factory from a photozoan association dominated by larger benthic foraminifera, corals, and red algae to a heterozoan association dominated by bryozoans. The same bryozoan fades occurs in several Italian localities near the Eocene-Oligocene boundary. This fades is interpreted to represent an analogue of modern cool-water carbonates and results from a cooling pulse of at least regional scale, associated to the Oi-1 event. KW - Eocene-Oligocene transition KW - Shallow-water carbonates KW - Carbon-isotope stratigraphy KW - Strontium-isotope stratigraphy KW - Sea-level changes Y1 - 2013 U6 - https://doi.org/10.1016/j.palaeo.2012.11.003 SN - 0031-0182 VL - 369 SP - 361 EP - 376 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Vicedo, Vicent A1 - Caus, Esmeralda A1 - Frijia, Gianluca T1 - Late Cretaceous alveolinaceans (larger foraminifera) of the Caribbean palaeobioprovince and their stratigraphic distribution JF - Journal of systematic palaeontology N2 - Architectural analysis of the Late Cretaceous alveolinaceans of the Caribbean palaeobioprovince has made it possible to separate four genera: Praechubbina, Chubbinella gen. nov., Chubbina and Caribalveolina. The first three genera belong to the family Rhapydioninidae, while the fourth is placed in the family Alveolinidae. Two species, Praechubbina breviclaustra and P. oxchucensis sp. nov., represent the primitive genus Praechubbina, while the species cardenasensis and obesa, previously ascribed to this genus, must be reassigned respectively to Chubbinella gen. nov. and Caribalveolina. The species Chubbina jamaicensis, C. macgillavryi and C. fourcadei sp. nov. complete the inventory of Chubbina. The alveolinid genus Caribalveolina comprises two species, C. obesa and C. michaudi. Caribbean alveolinaceans include two successive assemblages. The lower assemblage is characterized by Praechubbina oxchucensis, P. brevisclaustra, Chubbinella cardenasensis and Caribalveolina obesa. The upper assemblage is represented by the genus Chubbina, with C. fourcadei, C. jamaicensis and C. macgillavryi, and Caribalveolina michaudi. The age of the lower assemblage is uncertain (probably Late CampanianEarly Maastrichtian), while the upper assemblage has been dated by strontium isotope stratigraphy as Late Maastrichtian. KW - alveolinaceans KW - larger foraminifera KW - shell-architecture KW - Caribbean KW - biostratigraphy KW - Sr-isotope stratigraphy Y1 - 2013 U6 - https://doi.org/10.1080/14772019.2011.637517 SN - 1477-2019 VL - 11 IS - 1 SP - 1 EP - 25 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Palm, Juliane A1 - van Schaik, N. Loes M. B. A1 - Schröder-Esselbach, Boris T1 - Modelling distribution patterns of anecic, epigeic and endogeic earthworms at catchment-scale in agro-ecosystems JF - Pedobiologia : international journal of soil biology N2 - Species distribution models are useful for identifying driving environmental factors that determine earthworm distributions as well as for predicting earthworm distribution patterns and abundances at different scales. However, due to large efforts in data acquisition, studies on larger scales are rare and often focus on single species or earthworms in general. In this study, we use boosted regression tree models (BRTs) for predicting the distribution of the three functional earthworm types, i.e. anecics, endogeics and epigeics, in an agricultural area in Baden-Wurttemberg (Southwest Germany). First, we predicted presence and absence and later earthworm abundances, considering predictors depicting land management, topography, and soil conditions as well as biotic interaction by using the abundance of the other functional earthworm types. The final presence-absence models performed reasonably well, with explained deviances between 24 and 51% after crossvalidation. Models for abundances of anecics and endogeics were less successful, since the high small-scale variability and patchiness in earthworm abundance influenced the representativeness of the field measurements. This resulted in a significant model uncertainty, which is practically very difficult to overcome with earthworm sampling campaigns at the catchment scale. Results showed that management practices (i.e. disturbances), topography, soil conditions, and biotic interactions with other earthworm groups are the most relevant predictors for spatial distribution (incidence) patterns of all three functional groups. The response curves and contributions of predictors differ for the three functional earthworm types. Epigeics are also controlled by topographic features, endogeics by soil parameters. KW - Species distribution models KW - Earthworms KW - Soil hydrology KW - Boosted regression trees (BRT) KW - Distribution patterns KW - Biotic interactions Y1 - 2013 U6 - https://doi.org/10.1016/j.pedobi.2012.08.007 SN - 0031-4056 VL - 56 IS - 1 SP - 23 EP - 31 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Uhlemann, S. A1 - Bertelmann, Roland A1 - Merz, Bruno T1 - Data expansion the potential of grey literature for understanding floods JF - Hydrology and earth system sciences : HESS N2 - Sophisticated methods have been developed and become standard in analysing floods as well as for assessing flood risk. However, increasingly critique of the current standards and scientific practice can be found both in the flood hydrology community as well as in the risk community who argue that the considerable amount of information already available on natural disasters has not been adequately deployed and brought to effective use. We describe this phenomenon as a failure to synthesize knowledge that results from barriers and ignorance in awareness, use and management of the entire spectrum of relevant content, that is, data, information and knowledge. In this paper we argue that the scientific community in flood risk research ignores event-specific analysis and documentations as another source of data. We present results from a systematic search that includes an intensive study on sources and ways of information dissemination of flood-relevant publications. We obtain 186 documents that contain information on the sources, pathways, receptors and/or consequences for any of the 40 strongest trans-basin floods in Germany in the period 1952-2002. This study therefore provides the most comprehensive metadata collection of flood documentations for the considered geographical space and period. A total of 87.5% of all events have been documented, and especially the most severe floods have received extensive coverage. Only 30% of the material has been produced in the scientific/academic environment, and the majority of all documents (about 80%) can be considered grey literature (i.e. literature not controlled by commercial publishers). Therefore, ignoring grey sources in flood research also means ignoring the largest part of knowledge available on single flood events (in Germany). Further, the results of this study underpin the rapid changes in information dissemination of flood event literature over the last decade. We discuss the options and obstacles of incorporating this data into the knowledge-building process in light of the current technological developments and international, interdisciplinary debates for data curation. Y1 - 2013 U6 - https://doi.org/10.5194/hess-17-895-2013 SN - 1027-5606 VL - 17 IS - 3 SP - 895 EP - 911 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Heistermann, Maik A1 - Jacobi, S. A1 - Pfaff, T. T1 - Technical note an open source library for processing weather radar data (wradlib) JF - Hydrology and earth system sciences : HESS N2 - The potential of weather radar observations for hydrological and meteorological research and applications is undisputed, particularly with increasing world-wide radar coverage. However, several barriers impede the use of weather radar data. These barriers are of both scientific and technical nature. The former refers to inherent measurement errors and artefacts, the latter to aspects such as reading specific data formats, geo-referencing, visualisation. The radar processing library wradlib is intended to lower these barriers by providing a free and open source tool for the most important steps in processing weather radar data for hydro-meteorological and hydrological applications. Moreover, the community-based development approach of wradlib allows scientists to share their knowledge about efficient processing algorithms and to make this knowledge available to the weather radar community in a transparent, structured and well-documented way. Y1 - 2013 U6 - https://doi.org/10.5194/hess-17-863-2013 SN - 1027-5606 VL - 17 IS - 2 SP - 863 EP - 871 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Conradt, Tobias A1 - Wechsung, F. A1 - Bronstert, Axel T1 - Three perceptions of the evapotranspiration landscape comparing spatial patterns from a distributed hydrological model, remotely sensed surface temperatures, and sub-basin water balances JF - Hydrology and earth system sciences : HESS N2 - A problem encountered by many distributed hydrological modelling studies is high simulation errors at interior gauges when the model is only globally calibrated at the outlet. We simulated river runoff in the Elbe River basin in central Europe (148 268 km(2)) with the semi-distributed eco-hydrological model SWIM (Soil and Water Integrated Model). While global parameter optimisation led to Nash-Sutcliffe efficiencies of 0.9 at the main outlet gauge, comparisons with measured runoff series at interior points revealed large deviations. Therefore, we compared three different strategies for deriving sub-basin evapotranspiration: (1) modelled by SWIM without any spatial calibration, (2) derived from remotely sensed surface temperatures, and (3) calculated from long-term precipitation and discharge data. The results show certain consistencies between the modelled and the remote sensing based evapotranspiration rates, but there seems to be no correlation between remote sensing and water balance based estimations. Subsequent analyses for single sub-basins identify amongst others input weather data and systematic error amplification in inter-gauge discharge calculations as sources of uncertainty. The results encourage careful utilisation of different data sources for enhancements in distributed hydrological modelling. Y1 - 2013 U6 - https://doi.org/10.5194/hess-17-2947-2013 SN - 1027-5606 VL - 17 IS - 7 SP - 2947 EP - 2966 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Sommer, Michael A1 - Jochheim, H. A1 - Höhn, Axel A1 - Breuer, Jörn A1 - Zagorski, Z. A1 - Busse, J. A1 - Barkusky, Dietmar A1 - Meier, K. A1 - Puppe, D. A1 - Wanner, Manfred A1 - Kaczorek, Danuta T1 - Si cycling in a forest biogeosystem - the importance of transient state biogenic Si pools JF - Biogeosciences N2 - The relevance of biological Si cycling for dissolved silica (DSi) export from terrestrial biogeosystems is still in debate. Even in systems showing a high content of weatherable minerals, like Cambisols on volcanic tuff, biogenic Si (BSi) might contribute > 50% to DSi (Gerard et al., 2008). However, the number of biogeosystem studies is rather limited for generalized conclusions. To cover one end of controlling factors on DSi, i.e., weatherable minerals content, we studied a forested site with absolute quartz dominance (> 95 %). Here we hypothesise minimal effects of chemical weathering of silicates on DSi. During a four year observation period (05/2007-04/2011), we quantified (i) internal and external Si fluxes of a temperate-humid biogeosystem (beech, 120 yr) by BIOME-BGC (version ZALF), (ii) related Si budgets, and (iii) Si pools in soil and beech, chemically as well as by SEM-EDX. For the first time two compartments of biogenic Si in soils were analysed, i.e., phytogenic and zoogenic Si pool (testate amoebae). We quantified an average Si plant uptake of 35 kg Si ha(-1) yr(-1) - most of which is recycled to the soil by litterfall - and calculated an annual biosilicification from idiosomic testate amoebae of 17 kg Si ha(-1). The comparatively high DSi concentrations (6 mg L-1) and DSi exports (12 kg Si ha(-1) yr(-1)) could not be explained by chemical weathering of feldspars or quartz dissolution. Instead, dissolution of a relictic, phytogenic Si pool seems to be the main process for the DSi observed. We identified canopy closure accompanied by a disappearance of grasses as well as the selective extraction of pine trees 30 yr ago as the most probable control for the phenomena observed. From our results we concluded the biogeosystem to be in a transient state in terms of Si cycling. Y1 - 2013 U6 - https://doi.org/10.5194/bg-10-4991-2013 SN - 1726-4170 VL - 10 IS - 7 SP - 4991 EP - 5007 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Ozsayin, Erman A1 - Ciner, T. Attila A1 - Rojay, F. Bora A1 - Dirik, R. Kadir A1 - Melnick, Daniel A1 - Fernandez-Blanco, David A1 - Bertotti, Giovanni A1 - Schildgen, Taylor F. A1 - Garcin, Yannick A1 - Strecker, Manfred A1 - Sudo, Masafumi T1 - Plio-Quaternary extensional tectonics of the Central Anatolian Plateau a case study from the Tuz Golu Basin, Turkey JF - Turkish journal of earth sciences = Türk yerbilimleri dergisi N2 - The Tuz Golu Basin is the largest sedimentary depression located at the center of the Central Anatolian Plateau, an extensive, low-relief region with elevations of ca. 1 km located between the Pontide and Tauride mountains. Presently, the basin morphology and sedimentation processes are mainly controlled by the extensional Tuz Golu Fault Zone in the east and the transtensional Inonu-Eskisehir Fault System in the west. The purpose of this study is to contribute to the understanding of the Plio-Quaternary deformation history and to refine the timing of the latest extensional phase of the Tuz Golu Basin. Field observations, kinematic analyses, interpretations of seismic reflection lines, and Ar-40/Ar-39 dating of a key ignimbrite layer suggest that a regional phase of NNW-SSE to NE-SW contraction ended by 6.81 +/- 0.24 Ma and was followed by N-S to NE-SW extension during the Pliocene-Quaternary periods. Based on sedimentological and chronostratigraphic markers, the average vertical displacement rates over the past 5 or 3 Ma with respect to the central part of Tuz Golu Lake are 0.03 to 0.05 mm/year for the fault system at the western flank of the basin and 0.08 to 0.13 mm/year at the eastern flank. Paleo-shorelines of the Tuz Golu Lake, vestiges of higher lake levels related to Quaternary climate change, are important strain markers and were formed during Last Glacial Maximum conditions as indicated by a radiocarbon age of 21.8 +/- 0.4 ka BP obtained from a stromatolitic crust. Geomorphic observations and deformed lacustrine shorelines suggest that the main strand of the Tuz Golu Fault Zone straddling the foothills of the Sereflikochisar-Aksaray range has not been active during the Holocene. Instead, deformation appears to have migrated towards the interior of the basin along an offshore fault that runs immediately west of Sereflikochisar Peninsula. This basinward migration of deformation is probably associated with various processes acting at the lithospheric scale, such as plateau uplift and/or microplate extrusion. KW - Central Anatolia KW - Tuz Golu Basin KW - orogenic plateau evolution KW - extensional tectonics KW - kinematic analysis KW - lake shoreline Y1 - 2013 U6 - https://doi.org/10.3906/yer-1210-5 SN - 1300-0985 VL - 22 IS - 5 SP - 691 EP - 714 PB - Tübitak CY - Ankara ER - TY - JOUR A1 - Itoh, N. A1 - Marwan, Norbert T1 - An extended singular spectrum transformation (SST) for the investigation of Kenyan precipitation data JF - Nonlinear processes in geophysics N2 - In this paper a change-point detection method is proposed by extending the singular spectrum transformation (SST) developed as one of the capabilities of singular spectrum analysis (SSA). The method uncovers change points related with trends and periodicities. The potential of the proposed method is demonstrated by analysing simple model time series including linear functions and sine functions as well as real world data (precipitation data in Kenya). A statistical test of the results is proposed based on a Monte Carlo simulation with surrogate methods. As a result, the successful estimation of change points as inherent properties in the representative time series of both trend and harmonics is shown. With regards to the application, we find change points in the precipitation data of Kenyan towns (Nakuru, Naivasha, Narok, and Kisumu) which coincide with the variability of the Indian Ocean Dipole (IOD) suggesting its impact of extreme climate in East Africa. Y1 - 2013 U6 - https://doi.org/10.5194/npg-20-467-2013 SN - 1023-5809 VL - 20 IS - 4 SP - 467 EP - 481 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Zibulski, Romy A1 - Herzschuh, Ulrike A1 - Pestryakova, Luidmila Agafyevna A1 - Wolter, Juliane A1 - Mueller, S. A1 - Schilling, N. A1 - Wetterich, Sebastian A1 - Schirrmeister, Lutz A1 - Tian, Fang T1 - River flooding as a driver of polygon dynamics: modern vegetation data and a millennial peat record from the Anabar River lowlands (Arctic Siberia) JF - Biogeosciences N2 - The spatial and temporal variability of a low-centred polygon on the eastern floodplain area of the lower Anabar River (72.070 degrees N, 113.921 degrees E; northern Yakutia, Siberia) has been investigated using a multi-method approach. The present-day vegetation in each square metre was analysed, revealing a community of Larix, shrubby Betula, and Salix on the polygon rim, a dominance of Carex and Andromeda polifolia in the rim-to-pond transition zone, and a predominantly monospecific Scorpidium scorpioides coverage within the pond. The total organic carbon (TOC) content, TOC/TN (total nitrogen) ratio, grain size, vascular plant macrofossils, moss remains, diatoms, and pollen were analysed for two vertical sections and a sediment core from a transect across the polygon. Radiocarbon dating indicates that the formation of the polygon started at least 1500 yr ago; the general positions of the pond and rim have not changed since that time. Two types of pond vegetation were identified, indicating two contrasting development stages of the polygon. The first was a well-established moss association, dominated by submerged or floating Scorpidium scorpioides and/or Drepanocladus spp. and overgrown by epiphytic diatoms such as Tabellaria flocculosa and Eunotia taxa. This stage coincides temporally with a period in which the polygon was only drained by lateral subsurface water flow, as indicated by mixed grain sizes. A different moss association occurred during times of repeated river flooding (indicated by homogeneous medium-grained sand that probably accumulated during the annual spring snowmelt), characterized by an abundance of Meesia triquetra and a dominance of benthic diatoms (e. g. Navicula vulpina), indicative of a relatively high pH and a high tolerance of disturbance. A comparison of the local polygon vegetation (inferred from moss and macrofossil spectra) with the regional vegetation (inferred from pollen spectra) indicated that the moss association with Scorpidium scorpioides became established during relatively favourable climatic conditions, while the association dominated by Meesia triquetra occurred during periods of harsh climatic conditions. Our study revealed a strong riverine influence (in addition to climatic influences) on polygon development and the type of peat accumulated. Y1 - 2013 U6 - https://doi.org/10.5194/bg-10-5703-2013 SN - 1726-4170 VL - 10 IS - 8 SP - 5703 EP - 5728 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Huber, Robert A1 - Rigling, Andreas A1 - Bebi, Peter A1 - Brand, Fridolin Simon A1 - Briner, Simon A1 - Buttler, Alexandre A1 - Elkin, Che A1 - Gillet, Francois A1 - Gret-Regamey, Adrienne A1 - Hirschi, Christian A1 - Lischke, Heike A1 - Scholz, Roland Werner A1 - Seidl, Roman A1 - Spiegelberger, Thomas A1 - Walz, Ariane A1 - Zimmermann, Willi A1 - Bugmann, Harald T1 - Sustainable land use in Mountain Regions under global change synthesis across scales and disciplines JF - Ecology and society : a journal of integrative science for resilience and sustainability N2 - Mountain regions provide essential ecosystem goods and services (EGS) for both mountain dwellers and people living outside these areas. Global change endangers the capacity of mountain ecosystems to provide key services. The Mountland project focused on three case study regions in the Swiss Alps and aimed to propose land-use practices and alternative policy solutions to ensure the provision of key EGS under climate and land-use changes. We summarized and synthesized the results of the project and provide insights into the ecological, socioeconomic, and political processes relevant for analyzing global change impacts on a European mountain region. In Mountland, an integrative approach was applied, combining methods from economics and the political and natural sciences to analyze ecosystem functioning from a holistic human-environment system perspective. In general, surveys, experiments, and model results revealed that climate and socioeconomic changes are likely to increase the vulnerability of the EGS analyzed. We regard the following key characteristics of coupled human-environment systems as central to our case study areas in mountain regions: thresholds, heterogeneity, trade-offs, and feedback. Our results suggest that the institutional framework should be strengthened in a way that better addresses these characteristics, allowing for (1) more integrative approaches, (2) a more network-oriented management and steering of political processes that integrate local stakeholders, and (3) enhanced capacity building to decrease the identified vulnerability as central elements in the policy process. Further, to maintain and support the future provision of EGS in mountain regions, policy making should also focus on project-oriented, cross-sectoral policies and spatial planning as a coordination instrument for land use in general. KW - adaptive management KW - climate change KW - ecosystem services KW - experiments KW - interdisciplinary research KW - land-use change KW - modeling KW - transdisciplinary research Y1 - 2013 U6 - https://doi.org/10.5751/ES-05499-180336 SN - 1708-3087 VL - 18 IS - 3 PB - Resilience Alliance CY - Wolfville ER - TY - INPR A1 - Burgold, Julia A1 - Frenzel, Fabian A1 - Rolfes, Manfred T1 - Observations on slums and their touristification T2 - Die Erde : journal of the Geographical Society of Berlin ; Zeitschrift der Gesellschaft für Erdkunde zu Berlin Y1 - 2013 SN - 0013-9998 VL - 144 IS - 2 SP - CP2 EP - 104 PB - Gesellschaft für Erdkunde CY - Berlin ER - TY - JOUR A1 - Zimmermann, B. A1 - Zimmermann, Alexander A1 - Scheckenbach, H. L. A1 - Schmid, T. A1 - Hall, Jefferson. S. A1 - van Breugel, Michiel T1 - Changes in rainfall interception along a secondary forest succession gradient in lowland Panama JF - Hydrology and earth system sciences : HESS N2 - Secondary forests are rapidly expanding in tropical regions. Yet, despite the importance of understanding the hydrological consequences of land-cover dynamics, the relationship between forest succession and canopy interception is poorly understood. This lack of knowledge is unfortunate because rainfall interception plays an important role in regional water cycles and needs to be quantified for many modeling purposes. To help close this knowledge gap, we designed a throughfall monitoring study along a secondary succession gradient in a tropical forest region of Panama. The investigated gradient comprised 20 forest patches 3 to 130 yr old. We sampled each patch with a minimum of 20 funnel-type throughfall collectors over a continuous 2month period that had nearly 900 mm of rain. During the same period, we acquired forest inventory data and derived several forest structural attributes. We then applied simple and multiple regression models (Bayesian model averaging, BMA) and identified those vegetation parameters that had the strongest influence on the variation of canopy interception. Our analyses yielded three main findings. First, canopy interception changed rapidly during forest succession. After only a decade, throughfall volumes approached levels that are typical for mature forests. Second, a parsimonious (simple linear regression) model based on the ratio of the basal area of small stems to the total basal area outperformed more complex multivariate models (BMA approach). Third, based on complementary forest inventory data, we show that the influence of young secondary forests on interception in realworld fragmented landscapes might be detectable only in regions with a substantial fraction of young forests. Our re-sults suggest that where entire catchments undergo forest regrowth, initial stages of succession may be associated with a substantial decrease of streamflow generation. Our results further highlight the need to study hydrological processes in all forest succession stages, including early ones. Y1 - 2013 U6 - https://doi.org/10.5194/hess-17-4659-2013 SN - 1027-5606 SN - 1607-7938 VL - 17 IS - 11 SP - 4659 EP - 4670 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Oberhänsli, Roland A1 - Koralay, E. A1 - Candan, Osman A1 - Pourteau, Amaury A1 - Bousquet, Romain T1 - Late cretaceous eclogitic high-pressure relics in the Bitlis Massif JF - Geodinamica acta : revue de géologie dynamique et de géographie physique N2 - A new occurrence of eclogites was found in the Kesandere valley in the eastern most part of the Bitlis complex, SE Anatolia. These high-pressure (HP) relics were preserved in calc-arenitic metasediments within the high-grade metamorphic basement of the Bitlis complex. The eclogitic parageneses were strongly overprinted during decompression and heating. These new eclogites locality complements the evidence of blueschist-facies metamorphism documented recently in the meta-sedimentary cover sequence of this part of the Bitlis complex. Thermodynamic calculations suggest peak conditions of ca. 480-540 degrees C/1.9-2.4GPa. New U/Pb dates of 84.4 +/-.9 and 82.4 +/-.9Ma were obtained on zircons from two Kesandere eclogite samples. On the basis of geochemical criteria, these dates are interpreted to represent zircon crystallization during the eclogitic peak stage. Kesandere eclogites differ from those previously described in the western Bitlis complex (Mt. Gablor locality) in terms of lithologic association, protolithic origin, and peak P-T conditions (600-650 degrees C/1.0-2.0GPa, respectively). On the other hand, eclogitic metamorphism of Kesandere metasediments occurred shortly before blueschist-facies metamorphism of the sedimentary cover (79-74Ma Ar-40/Ar-39 white mica). Therefore, the exhumation of Kesandere eclogites started between ca. 82 and 79Ma, while the meta-sedimentary cover was being buried. During this short time span, Kesandere eclogite were likely uplifted from similar to 65 to 35km depth, indicating a syn-subduction exhumation rate of similar to 4.3mm/a. Subsequently, eclogite- and blueschist-facies rocks were likely retrogressed contemporarily during collision-type metamorphism (around 72-69Ma). The Bitlis HP rocks thus sample a subduction zone that separated the Bitlis-Puturge (Bistun?) block from the South-Armenian block, further north. To the south, Eocene metasediments of the Urse formation are imbricated below the Bitlis complex. They contain (post Eocene) blueschists, testifying separation from the Arabian plate and southward migration of the subduction zone. The HT overprint of Kesandere eclogites can be related to the asthenospheric flow provoked by subducting slab retreat or break off. KW - eclogites KW - zircon KW - U KW - Pb ages KW - E Anatolia KW - subduction-collision Y1 - 2013 U6 - https://doi.org/10.1080/09853111.2013.858951 SN - 0985-3111 SN - 1778-3593 VL - 26 IS - 3-4 SP - 175 EP - 190 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Heckmann, Tobias A1 - Schwanghart, Wolfgang T1 - Geomorphic coupling and sediment connectivity in an alpine catchment - Exploring sediment cascades using graph theory JF - Geomorphology : an international journal on pure and applied geomorphology N2 - Through their relevance for sediment budgets and the sensitivity of geomorphic systems, geomorphic coupling and (sediment) connectivity represent important topics in geomorphology. Since the introduction of the systems perspective to physical geography by Chorley and Kennedy (1971), a catchment has been perceived as consisting of landscape elements (e.g. landforms, subcatchments) that are coupled by geomorphic processes through sediment transport. In this study, we present a novel application of mathematical graph theory to explore the network structure of coarse sediment pathways in a central alpine catchment. Numerical simulation models for rockfall, debris flows, and (hillslope and channel) fluvial processes are used to establish a spatially explicit graph model of sediment sources, pathways and sinks. The raster cells of a digital elevation model form the nodes of this graph, and simulated sediment trajectories represent the corresponding edges. Model results are validated by visual comparison with the field situation and aerial photos. The interaction of sediment pathways, i.e. where the deposits of a geomorphic process form the sources of another process, forms sediment cascades, represented by paths (a succession of edges) in the graph model. We show how this graph can be used to explore upslope (contributing area) and downslope (source to sink) functional connectivity by analysing its nodes, edges and paths. The analysis of the spatial distribution, composition and frequency of sediment cascades yields information on the relative importance of geomorphic processes and their interaction (however regardless of their transport capacity). In the study area, the analysis stresses the importance of mass movements and their interaction, e.g. the linkage of large rockfall source areas to debris flows that potentially enter the channel network. Moreover, it is shown that only a small percentage of the study area is coupled to the channel network which itself is longitudinally disconnected by natural and anthropogenic barriers. Besides the case study, we discuss the methodological framework and alternatives for node and edge representations of graph models in geomorphology. We conclude that graph theory provides an excellent methodological framework for the analysis of geomorphic systems, especially for the exploration of quantitative approaches towards sediment connectivity. KW - Geomorphic coupling KW - Sediment connectivity KW - Sediment cascades KW - Graph theory Y1 - 2013 U6 - https://doi.org/10.1016/j.geomorph.2012.10.033 SN - 0169-555X VL - 182 IS - 2 SP - 89 EP - 103 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kahmen, Ansgar A1 - Schefuss, Enno A1 - Sachse, Dirk T1 - Leaf water deuterium enrichment shapes leaf wax n-alkane delta D values of angiosperm plants I experimental evidence and mechanistic insights JF - Geochimica et cosmochimica acta : journal of the Geochemical Society and the Meteoritical Society N2 - Leaf wax n-alkanes of terrestrial plants are long-chain hydrocarbons that can persist in sedimentary records over geologic timescales. Since meteoric water is the primary source of hydrogen used in leaf wax synthesis, the hydrogen isotope composition (delta D value) of these biomarkers contains information on hydrological processes. Consequently, leaf wax n-alkane delta D values have been advocated as powerful tools for paleohydrological research. The exact kind of hydrological information that is recorded in leaf wax n-alkanes remains, however, unclear because critical processes that determine their delta D values have not yet been resolved. In particular the effects of evaporative deuterium (D)-enrichment of leaf water on the delta D values of leaf wax n-alkanes have not yet been directly assessed and quantified. Here we present the results of a study where we experimentally tested if and by what magnitude evaporative D-enrichment of leaf water affects the delta D of leaf wax n-alkanes in angiosperm C3 and C4 plants. Our study revealed that n-alkane delta D values of all plants that we investigated were affected by evaporative D-enrichment of leaf water. For dicotyledonous plants we found that the full extent of leaf water evaporative D-enrichment is recorded in leaf wax n-alkane delta D values. For monocotyledonous plants we found that between 18% and 68% of the D-enrichment in leaf water was recorded in the delta D values of their n-alkanes. We hypothesize that the different magnitudes by which evaporative D-enrichment of leaf water affects the delta D values of leaf wax n-alkanes in monocotyledonous and dicotyledonous plants is the result of differences in leaf growth and development between these plant groups. Our finding that the evaporative D-enrichment of leaf water affects the delta D values of leaf wax n-alkanes in monocotyledonous and dicotyledonous plants albeit at different magnitudes - has important implications for the interpretation of leaf wax n-alkane delta D values from paleohydrological records. In addition, our finding opens the door to employ delta D values of leaf wax n-alkanes as new ecohydrological proxies for evapotranspiration that can be applied in contemporary plant and ecosystem research. Y1 - 2013 U6 - https://doi.org/10.1016/j.gca.2012.09.003 SN - 0016-7037 VL - 111 SP - 39 EP - 49 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Beyene, Yonas A1 - Katoh, Shigehiro A1 - Wolde Gabriel, Giday A1 - Hart, William K. A1 - Uto, Kozo A1 - Sudo, Masafumi A1 - Kondo, Megumi A1 - Hyodo, Masayuki A1 - Renne, Paul R. A1 - Suwa, Gen A1 - Asfaw, Berhane T1 - The characteristics and chronology of the earliest. Acheulean at Konso, Ethiopia JF - Proceedings of the National Academy of Sciences of the United States of America N2 - The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6-1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period similar to 1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world's earliest with an age of similar to 1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at similar to 1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology. KW - chronostratigraphy KW - Early Pleistocene KW - lithic technology development Y1 - 2013 U6 - https://doi.org/10.1073/pnas.1221285110 SN - 0027-8424 VL - 110 IS - 5 SP - 1584 EP - 1591 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Huang, Shaochun A1 - Hattermann, Fred A1 - Krysanova, Valentina A1 - Bronstert, Axel T1 - Projections of climate change impacts on river flood conditions in Germany by combining three different RCMs with a regional eco-hydrological model JF - Climatic change : an interdisciplinary, intern. journal devoted to the description, causes and implications of climatic change N2 - A general increase in precipitation has been observed in Germany in the last century, and potential changes in flood generation and intensity are now at the focus of interest. The aim of the paper is twofold: a) to project the future flood conditions in Germany accounting for various river regimes (from pluvial to nival-pluvial regimes) and under different climate scenarios (the high, A2, low, B1, and medium, A1B, emission scenarios) and b) to investigate sources of uncertainty generated by climate input data and regional climate models. Data of two dynamical Regional Climate Models (RCMs), REMO (REgional Model) and CCLM (Cosmo-Climate Local Model), and one statistical-empirical RCM, Wettreg (Wetterlagenbasierte Regionalisierungsmethode: weather-type based regionalization method), were applied to drive the eco-hydrological model SWIM (Soil and Water Integrated Model), which was previously validated for 15 gauges in Germany. At most of the gauges, the 95 and 99 percentiles of the simulated discharge using SWIM with observed climate data had a good agreement with the observed discharge for 1961-2000 (deviation within +/- 10 %). However, the simulated discharge had a bias when using RCM climate as input for the same period. Generalized Extreme Value (GEV) distributions were fitted to the annual maximum series of river runoff for each realization for the control and scenario periods, and the changes in flood generation over the whole simulation time were analyzed. The 50-year flood values estimated for two scenario periods (2021-2060, 2061-2100) were compared to the ones derived from the control period using the same climate models. The results driven by the statistical-empirical model show a declining trend in the flood level for most rivers, and under all climate scenarios. The simulations driven by dynamical models give various change directions depending on region, scenario and time period. The uncertainty in estimating high flows and, in particular, extreme floods remains high, due to differences in regional climate models, emission scenarios and multi-realizations generated by RCMs. Y1 - 2013 U6 - https://doi.org/10.1007/s10584-012-0586-2 SN - 0165-0009 SN - 1573-1480 VL - 116 IS - 3-4 SP - 631 EP - 663 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Vorpahl, Peter A1 - Dislich, Claudia A1 - Elsenbeer, Helmut A1 - Märker, Michael A1 - Schröder-Esselbach, Boris T1 - Biotic controls on shallow translational landslides JF - Earth surface processes and landforms : the journal of the British Geomorphological Research Group N2 - In undisturbed tropical montane rainforests massive organic layers accommodate the majority of roots and only a small fraction of roots penetrate the mineral soil. We investigated the contribution of vegetation to slope stability in such environments by modifying a standard model for slope stability to include an organic layer with distinct mechanical properties. The importance of individual model parameters was evaluated using detailed measurements of soil and vegetation properties to reproduce the observed depth of 11 shallow landslides in the Andes of southern Ecuador. By distinguishing mineral soil, organic layer and above-ground biomass, it is shown that in this environment vegetation provides a destabilizing effect mainly due to its contribution to the mass of the organic layer (up to 973 t ha-1 under wet conditions). Sensitivity analysis shows that the destabilizing effect of the mass of soil and vegetation can only be effective on slopes steeper than 37.9 degrees. This situation applies to 36% of the study area. Thus, on the steep slopes of this megadiverse ecosystem, the mass of the growing forest promotes landsliding, which in turn promotes a new cycle of succession. This feedback mechanism is worth consideration in further investigations of the impact of landslides on plant diversity in similar environments. KW - shallow translational landslides KW - tropical montane forest KW - biomass KW - organic layer Y1 - 2013 U6 - https://doi.org/10.1002/esp.3320 SN - 0197-9337 VL - 38 IS - 2 SP - 198 EP - 212 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Sobel, Edward A1 - Chen, Jie A1 - Schoenbohm, Lindsay M. A1 - Thiede, Rasmus Christoph A1 - Stockli, Daniel F. A1 - Sudo, Masafumi A1 - Strecker, Manfred T1 - Oceanic-style subduction controls late Cenozoic deformation of the Northern Pamir orogen JF - Earth & planetary science letters N2 - The northern part of the Pamir orogen is the preeminent example of an active intracontinental subduction zone in the early stages of continent-continent collision. Such zones are the least understood type of plate boundaries because modern examples are few and of limited access, and ancient analogs have been extensively overprinted by subsequent tectonic and erosion processes. In the Pamir, it has been assumed that most of the plate convergence was accommodated by overthrusting along the plate-bounding Main Pamir Thrust (MPT), which forms the principal northern mountain and deformation front of the Pamir. However, the synopsis of our new and previously published thermochronologic data from this region shows that the hanging wall of the MPT experienced relatively minor amounts of late Cenozoic exhumation. The Pamir orogen as a whole is an integral part of the overriding plate in a subduction system, while the remnant basin to the north constitutes the downgoing plate, with the bulk of the convergence accommodated by underthrusting. Herein, we demonstrate that the observed deformation of the upper and lower plates within the Pamir-Alai convergence zone resembles highly arcuate oceanic subduction systems characterized by slab rollback, subduction erosion, subduction accretion, and marginal slab-tear faults. We suggest that the curvature of the North Pamir is genetically linked to the short width and rollback of the south-dipping Alai slab; northward motion (indentation) of the Pamir is accommodated by crustal processes related to this rollback. The onset of south-dipping subduction is tentatively linked to intense Pamir contraction following break-off of the north-dipping Indian slab beneath the Karakoram. KW - subduction accretion KW - subduction erosion KW - exhumation KW - thermochronology KW - intracontinental deformation KW - Pamir Y1 - 2013 U6 - https://doi.org/10.1016/j.epsl.2012.12.009 SN - 0012-821X VL - 363 IS - 1 SP - 204 EP - 218 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Knapmeyer-Endrun, Brigitte A1 - Krüger, Frank A1 - Legendre, C. P. A1 - Geissler, Wolfram H. T1 - Tracing the influence of the trans-european suture zone into the mantle transition zone JF - Earth & planetary science letters N2 - Cratons with their thick lithospheric roots can influence the thermal structure, and thus the convective flow, in the surrounding mantle. As mantle temperatures are hard to measure directly, depth variations in the mantle transition zone (MTZ) discontinuities are often employed as a proxy. Here, we use a large new data set of P-receiver functions to map the 410 km and 660 km discontinuities beneath the western edge of the East European Craton and adjacent Phanerozoic Europe across the most fundamental lithospheric boundary in Europe, the Trans-European Suture Zone (TESZ). We observe significantly shorter travel times for conversions from both MTZ discontinuities within the craton, caused by the high velocities of the cratonic root. By contrast, the differential travel time across the MTZ is normal to only slightly raised. This implies that any insulating effect of the cratonic keel does not reach the MTZ. In contrast to earlier observations in Siberia, we do not find any trace of a discontinuity at 520 km depth, which indicates a rather dry MTZ beneath the western edge of the craton. Within most of covered Phanerozoic Europe, the MTZ differential travel time is remarkably uniform and in agreement with standard Earth models. No widespread thermal effects of the various episodes of Caledonian and Variscan subduction that took place during the amalgamation of the continent remain. Only more recent tectonic events, related to Alpine subduction and Quarternary volcanism in the Eifel area, can be traced. While the East European craton shows no distinct imprint into the MTZ, we discover the signature of the TESZ in the MTZ in the form of a linear region of about 350 km width with a 1.5 s increase in differential travel time, which could either be caused by high water content or decreased temperature. Taking into account results of recent S-wave tomographies, raised water content in the MTZ cannot be the main cause for this observation. Accordingly, we explain the increase, equivalent to a 15 km thicker MTZ, by a temperature decrease of about 80 K. We discuss two alternative models for this temperature reduction, either a remnant of subduction or an indication of downwelling due to small-scale, edge-driven convection caused by the contrast in lithospheric thickness across the TESZ. Any subducted lithosphere found in the MTZ at this location is unlikely to be related to Variscan subduction along the TESZ, though, as Eurasia has moved significantly northward since the Variscan orogeny. KW - mantle transition zone KW - Trans-European Suture Zone KW - East European Craton KW - edge-driven convection KW - receiver functions Y1 - 2013 U6 - https://doi.org/10.1016/j.epsl.2012.12.028 SN - 0012-821X SN - 1385-013X VL - 363 SP - 73 EP - 87 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Sirocko, Frank A1 - Dietrich, Stephan A1 - Veres, Daniel A1 - Grootes, Pieter M. A1 - Schaber-Mohr, Katja A1 - Seelos, Klemens A1 - Nadeau, Marie-Josee A1 - Kromer, Bernd A1 - Rothacker, Leo A1 - Roehner, Marieke A1 - Krbetschek, Matthias A1 - Appleby, Peter G. A1 - Hambach, Ulrich A1 - Rolf, Christian A1 - Sudo, Masafumi A1 - Grim, Stephanie T1 - Multi-proxy dating of Holocene maar lakes and Pleistocene dry maar sediments in the Eifel, Germany JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - During the last twelve years the ELSA Project (Eifel Laminated Sediment Archive) at Mainz University has drilled a total of about 52 cores from 27 maar lakes and filled-in maar basins in the Eifel/Germany. Dating has been completed for the Holocene cores using 6 different methods (Pb-210 and Cs-137 activities, palynostratigraphy, event markers, varve counting, C-14) In general, the different methods consistently complement one another within error margins. Event correlation was used for relating typical lithological changes with historically known events such as the two major Holocene flood events at 1342 AD and ca 800 BC. Dating of MIS2-MIS3 core sections is based on greyscale tuning, radiocarbon and OSL dating, magnetostratigraphy and tephrochronology. The lithological changes in the sediment cores demonstrate a sequence of events similar to the North Atlantic rapid climate variability of the Last Glacial Cycle. The warmest of the MIS3 interstadials was GI14, when a forest with abundant spruce covered the Eifel area from 55 to 48 ka BP, i.e. during a time when also other climate archives in Europe suggested very warm conditions. The forest of this "Early Stage 3 warm phase" developed subsequently into a steppe with scattered birch and pine, and finally into a glacial desert at around 25 ka BP. Evidence for Mono Lake and Laschamp geomagnetic excursions is found in two long cores. Several large eruptions during Middle and Late Pleistocene (Ulmener Maar - 11,000 varve years BP, Laacher See - 12,900 varve years BP, Mosenberg volcanoes/Meerfelder Maar 41-45 cal ka BP, Dumpel Maar 116 ka BP, Glees Maar - 151 ka BP) produced distinct ash-layers crucial for inter-core and inter-site correlations. The oldest investigated maar of the Eifel is Ar-40/Ar-39 dated to the time older than 520 ka BP. KW - Eifel maar KW - Laminated lake sediments KW - Tuning KW - Historical events KW - C-14-derived chronology KW - Varve counting KW - Luminescence dating KW - Palynostratigraphy KW - (CS)-C-137 and Pb-210 dating KW - Palaeomagnetism KW - Tephrostratigraphy KW - Argon-Argon dating KW - GIS Y1 - 2013 U6 - https://doi.org/10.1016/j.quascirev.2012.09.011 SN - 0277-3791 VL - 62 SP - 56 EP - 76 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Richter, Dania A1 - Schröder-Esselbach, Boris A1 - Hartmann, Niklas K. A1 - Matuschka, Franz-Rainer T1 - Spatial stratification of various Lyme disease spirochetes in a Central European site JF - FEMS microbiology ecology N2 - To determine whether the genospecies composition of Lyme disease spirochetes is spatially stratified, we collected questing Ixodes ricinus ticks in neighboring plots where rodents, birds, and lizards were present as reservoir host and compared the prevalence of various genospecies. The overall prevalence of spirochetes in questing ticks varied across the study site. Borrelia lusitaniae appeared to infect adult ticks in one plot at the same frequency as did Borrelia afzelii in the other plots. The relative density of questing nymphal and adult ticks varied profoundly. Where lizards were exceedingly abundant, these vertebrates seemed to constitute the dominant host for nymphal ticks, contributing the majority of infected adult ticks. Because lizards support solely B.lusitaniae and appear to exclude other genospecies, their narrow genospecies association results in predominance of B.lusitaniae in sites where lizards are abundant, while limiting its spread to the host's habitat range. To the extent that Central European B.lusitaniae strains are nonpathogenic, the presence of numerous lizards should locally decrease risk of infection for people. Evaluation of regional risk of infection by Lyme disease spirochetes should take the spatial effect of hosts into consideration, which stratify the distribution of specifically infected ticks on a small scale. KW - Lyme disease KW - Borrelia lusitaniae KW - Borrelia afzelii KW - stratification KW - lizard KW - zooprophylaxis Y1 - 2013 U6 - https://doi.org/10.1111/1574-6941.12029 SN - 0168-6496 VL - 83 IS - 3 SP - 738 EP - 744 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Hinzen, Klaus-G A1 - Reamer, Sharon K. A1 - Scherbaum, Frank T1 - Slow fourier transform JF - Seismological research letters Y1 - 2013 U6 - https://doi.org/10.1785/0220120139 SN - 0895-0695 VL - 84 IS - 2 SP - 251 EP - 257 PB - Seismological Society of America CY - Albany ER - TY - JOUR A1 - Zimmermann, Alexander A1 - Schinn, Dustin S. A1 - Francke, Till A1 - Elsenbeer, Helmut A1 - Zimmermann, Beate T1 - Uncovering patterns of near-surface saturated hydraulic conductivity in an overland flow-controlled landscape JF - Geoderma : an international journal of soil science N2 - Saturated hydraulic conductivity (K-s) is an important soil characteristic affecting soil water storage, runoff generation and erosion processes. In some areas where high-intensity rainfall coincides with low K-s values at shallow soil depths, frequent overland flow entails dense drainage networks. Consequently, linear structures such as flowlines alternate with inter-flowline areas. So far, investigations of the spatial variability of K-s mainly relied on isotropic covariance models which are unsuitable to reveal patterns resulting from linear structures. In the present study, we applied two sampling approaches so as to adequately characterize K-s spatial variability in a tropical forest catchment that features a high density of flowlines: A classical nested sampling survey and a purposive sampling strategy adapted to the presence of flowlines. The nested sampling approach revealed the dominance of small-scale variability, which is in line with previous findings. Our purposive sampling, however, detected a strong spatial gradient: surface K-s increased substantially as a function of distance to flowline; 10 m off flowlines, values were similar to the spatial mean of K-s. This deterministic trend can be included as a fixed effect in a linear mixed modeling framework to obtain realistic spatial fields of K-s. In a next step we used probability maps based on those fields and prevailing rainfall intensities to assess the hydrological relevance of the detected pattern. This approach suggests a particularly good agreement between the probability statements of K-s exceedance and observed overland flow occurrence during wet stages of the rainy season. KW - Soil hydrology KW - Saturated hydraulic conductivity KW - Overland flow generation KW - Spatial patterns KW - Drainage network Y1 - 2013 U6 - https://doi.org/10.1016/j.geoderma.2012.11.002 SN - 0016-7061 VL - 195 IS - 169 SP - 1 EP - 11 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hikel, Harald A1 - Yair, Aaron A1 - Schwanghart, Wolfgang A1 - Hoffmann, Ulrike A1 - Strähl, Sarah A1 - Kuhn, Nikolaus J. T1 - Experimental investigation of soil ecohydrology on rocky desert slopes in the Negev Highlands, Israel JF - Zeitschrift für Geomorphologie N2 - Purpose: Dry land vegetation is expected to respond sensitively to climate change and the projected variability of rainfall events. Rainfall as a water source is an obvious factor for the water supply of vegetation. However, the interaction of water and surface on rocky desert slopes with a patchy soil cover is also vital for vegetation in drylands. In particular, runoff on rocky surfaces and infiltration capacity of soil patches determine plant available water. Process-based studies into rock-soil interaction benefit from rainfall simulation, but require an approach accounting for the micro-scale heterogeneity of the slope surfaces. This study therefore aims at developing a suitable procedure for examining rock-soil interaction and the relevance of soil volume for storing plant available water in the northern Negev, Israel. Materials and methods: To determine the amount of rainfall required to fill the available soil water storage capacity rainfall simulation experiments were conducted. The design of the rainfall-simulator and the selection of the plots aimed specifically at observing infiltration into small soil patches on a micro-scale relevant for the prevalent vegetation cover. Results and discussion: The preliminary results of the study in the Negev Desert indicate that the ratio between soil volume and frequency of rainfall events determine the effect of climate change on plant available water and thus ultimately vegetation cover. Conclusions: Based on the experiments examining runoff and soil moisture the qualitative understanding of hillslope ecohydrology in a rocky desert environment can be expanded into a quantitative assessment of the potential impact of varying rainfall conditions. The study also illustrates the contribution of rainfall simulation experiments for studies on the impact of climate change. KW - Drylands KW - Ecohydrology KW - Rocky deserts KW - Rainfall simulation Y1 - 2013 U6 - https://doi.org/10.1127/0372-8854/2012/S-00116 SN - 0372-8854 VL - 57 IS - 2 SP - 39 EP - 58 PB - Cramer CY - Stuttgart ER - TY - JOUR A1 - Deplazes, Gaudenz A1 - Lueckge, Andreas A1 - Peterson, Larry C. A1 - Timmermann, Axel A1 - Hamann, Yvonne A1 - Hughen, Konrad A. A1 - Roehl, Ursula A1 - Laj, Carlo A1 - Cane, Mark A. A1 - Sigman, Daniel M. A1 - Haug, Gerald H. T1 - Links between tropical rainfall and North Atlantic climate during the last glacial period JF - Nature geoscience N2 - During the last glacial period, the North Atlantic region experienced pronounced, millennial-scale alternations between cold, stadial conditions and milder interstadial conditions-commonly referred to as Dansgaard-Oeschger oscillations-as well as periods of massive iceberg discharge known as Heinrich events(1). Changes in Northern Hemisphere temperature, as recorded in Greenland(2-4), are thought to have affected the location of the Atlantic intertropical convergence zone(5,6) and the strength of the Indian summer monsoon(7,8). Here we use high-resolution records of sediment colour-a measure of terrigenous versus biogenic content-from the Cariaco Basin off the coast of Venezuela and the Arabian Sea to assess teleconnections with the North Atlantic climate system during the last glacial period. The Cariaco record indicates that the intertropical convergence zone migrated seasonally over the site during mild stadial conditions, but was permanently displaced south of the basin during peak stadials and Heinrich events. In the Arabian Sea, we find evidence of a weak Indian summer monsoon during the stadial events. The tropical records show a more variable response to North Atlantic cooling than the Greenland temperature records. We therefore suggest that Greenland climate is especially sensitive to variations in the North Atlantic system-in particular sea-ice extent-whereas the intertropical convergence zone and Indian monsoon system respond primarily to variations in mean Northern Hemisphere temperature. Y1 - 2013 U6 - https://doi.org/10.1038/ngeo1712 SN - 1752-0894 VL - 6 IS - 3 SP - 213 EP - 217 PB - Nature Publ. Group CY - New York ER - TY - JOUR A1 - Krause, Stefan A1 - Tecklenburg, Christina A1 - Munz, Matthias A1 - Naden, Emma T1 - Streambed nitrogen cycling beyond the hyporheic zone: Flow controls on horizontal patterns and depth distribution of nitrate and dissolved oxygen in the upwelling groundwater of a lowland river JF - Journal of geophysical research : Biogeosciences N2 - Biogeochemical turnover in hyporheic zones is known to have the potential to affect the chemical signature of surface water cycling through shallow streambed sediments. This study investigates the impact of streambed physical properties on the fate of nitrate and dissolved oxygen in groundwater upwelling through the streambed of a lowland river. For analyzing depth-dependent patterns and zonation of nitrogen concentrations, diffuse gel probes in shallow (top 15 cm) streambed sediments have been deployed in a nested setup together with multilevel minipiezometers for streambed sediments of 15-150 cm. Spatial heterogeneity of groundwater upwelling was controlled by patterns of low-conductivity peat and clay strata that caused locally confined conditions, suggesting increased streambed residence times. Nitrate concentrations in the upwelling groundwater changed by up to 68.06 mg L-1 within the top 15 cm of streambed sediments and by up to 107.47 mg L-1 at depths of 15-150 cm, indicating that significant nitrogen turnover was not restricted to shallow streambed sediments. Intensive reduction of nitrate concentrations was found, in particular, in vicinity of low-conductivity streambed strata. The coincidence of confined groundwater upwelling and reduced oxygen concentrations at these locations suggests that increased residence times and associated depletion of dissolved oxygen create conditions favorable for nitrate reduction. Our results highlight that increased nitrogen turnover at aquifer-river interfaces is not necessarily limited to shallow streambed zones, where surface water is mixing with groundwater, but can affect upwelling groundwater in reactive hot spots that extend to greater streambed depths and beyond hyporheic mixing zones. Citation: Krause, S., C. Tecklenburg, M. Munz, and E. Naden (2013), Streambed nitrogen cycling beyond the hyporheic zone: Flow controls on horizontal patterns and depth distribution of nitrate and dissolved oxygen in the upwelling groundwater of a lowland river, Y1 - 2013 U6 - https://doi.org/10.1029/2012JG002122 SN - 0148-0227 VL - 118 IS - 1 SP - 54 EP - 67 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Cosentino, Domenico A1 - Buchwaldt, Robert A1 - Sampalmieri, Gianluca A1 - Iadanza, Annalisa A1 - Cipollari, Paola A1 - Schildgen, Taylor F. A1 - Hinnov, Linda A. A1 - Ramezani, Jahandar A1 - Bowring, Samuel A. T1 - Refining the mediterranean "Messinian gap" with high-precision U-Pb zircon geochronology, central and northern Italy JF - Geology N2 - Astronomically tuned cyclic sedimentary successions provide unprecedented insight into the temporal evolution of depositional systems and major geologic events. However, placing astronomically calibrated records into an absolute time frame with confidence requires independent and precise geochronologic constraints. Astronomical tuning of the precessionally modulated sedimentary cycles of the Mediterranean Basin deposited during the Messinian Salinity Crisis (5.96-5.33 Ma) has indicated an similar to 90 k.y. "Messinian gap", corresponding to the evaporative drawdown of the Mediterranean following the closure of the Mediterranean-Atlantic gateway. In the Messinian deposits, a volcanic ash dated by Ar-40/Ar-39 geochronology was used to anchor the sedimentary cycles to the insolation curve. However, the uncertainty of the Ar-40/Ar-39 date introduces a potential two-cycle (similar to 40 k.y.) uncertainty in the tuning. Using high-precision chemical abrasion-thermal ionization mass spectrometry (CA-TIMS) U-Pb geochronology on single zircon grains from two Messinian ash layers in Italy, we obtained dates of 5.5320 +/- 0.0046 Ma and 5.5320 +/- 0.0074 Ma with sub-precessional resolution. Combined with our astronomical tuning of the Messinian Lower Evaporites, the results refine the duration of the "Messinian gap" to at most 28 or 58 +/- 9.6 k.y., which correlates with either the TG12 glacial interval alone, or both TG12 and TG14 glacial intervals, supporting the hypothesis of a glacio-eustatic contribution in fully isolating the Mediterranean from the Atlantic Ocean. Our new U-Pb dates also allow us to infer a precessionally modulated cyclicity for the post-evaporitic deposits, and hence enable us to tune those successions to the insolation curve. Y1 - 2013 U6 - https://doi.org/10.1130/G33820.1 SN - 0091-7613 VL - 41 IS - 3 SP - 323 EP - 326 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Jeltsch, Florian A1 - Blaum, Niels A1 - Brose, Ulrich A1 - Chipperfield, Joseph D. A1 - Clough, Yann A1 - Farwig, Nina A1 - Geissler, Katja A1 - Graham, Catherine H. A1 - Grimm, Volker A1 - Hickler, Thomas A1 - Huth, Andreas A1 - May, Felix A1 - Meyer, Katrin M. A1 - Pagel, Jörn A1 - Reineking, Björn A1 - Rillig, Matthias C. A1 - Shea, Katriona A1 - Schurr, Frank Martin A1 - Schroeder, Boris A1 - Tielbörger, Katja A1 - Weiss, Lina A1 - Wiegand, Kerstin A1 - Wiegand, Thorsten A1 - Wirth, Christian A1 - Zurell, Damaris T1 - How can we bring together empiricists and modellers in functional biodiversity research? JF - Basic and applied ecology : Journal of the Gesellschaft für Ökologie N2 - Improving our understanding of biodiversity and ecosystem functioning and our capacity to inform ecosystem management requires an integrated framework for functional biodiversity research (FBR). However, adequate integration among empirical approaches (monitoring and experimental) and modelling has rarely been achieved in FBR. We offer an appraisal of the issues involved and chart a course towards enhanced integration. A major element of this path is the joint orientation towards the continuous refinement of a theoretical framework for FBR that links theory testing and generalization with applied research oriented towards the conservation of biodiversity and ecosystem functioning. We further emphasize existing decision-making frameworks as suitable instruments to practically merge these different aims of FBR and bring them into application. This integrated framework requires joint research planning, and should improve communication and stimulate collaboration between modellers and empiricists, thereby overcoming existing reservations and prejudices. The implementation of this integrative research agenda for FBR requires an adaptation in most national and international funding schemes in order to accommodate such joint teams and their more complex structures and data needs. KW - Biodiversity theory KW - Biodiversity experiments KW - Conservation management KW - Decision-making KW - Ecosystem functions and services KW - Forecasting KW - Functional traits KW - Global change KW - Monitoring programmes KW - Interdisciplinarity Y1 - 2013 U6 - https://doi.org/10.1016/j.baae.2013.01.001 SN - 1439-1791 VL - 14 IS - 2 SP - 93 EP - 101 PB - Elsevier CY - Jena ER - TY - JOUR A1 - Böttle, Markus A1 - Rybski, Diego A1 - Kropp, Jürgen T1 - How changing sea level extremes and protection measures alter coastal flood damages JF - Water resources research N2 - While sea level rise is one of the most likely consequences of climate change, the provoked costs remain highly uncertain. Based on a block-maxima approach, we provide a stochastic framework to estimate the increase of expected damages with sea level rise as well as with meteorological changes and demonstrate the application to two case studies. In addition, the uncertainty of the damage estimations due to the stochastic nature of extreme events is studied. Starting with the probability distribution of extreme flood levels, we calculate the distribution of implied damages in a specific region employing stage-damage functions. Universal relations of the expected damages and their standard deviation, which demonstrate the importance of the shape of the damage function, are provided. We also calculate how flood protection reduces the damages leading to a more complex picture, where the extreme value behavior plays a fundamental role. Citation: Boettle, M., D. Rybski, and J. P. Kropp (2013), How changing sea level extremes and protection measures alter coastal flood damages, Water Resour. Res., 49, 1199-1210, doi: 10.1002/wrcr.20108. Y1 - 2013 U6 - https://doi.org/10.1002/wrcr.20108 SN - 0043-1397 VL - 49 IS - 3 SP - 1199 EP - 1210 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Taft, Linda A1 - Wiechert, Uwe A1 - Zhang, Hucai A1 - Lei, Guoliang A1 - Mischke, Steffen A1 - Plessen, Birgit A1 - Weynell, Marc A1 - Winkler, Andreas A1 - Riedel, Frank T1 - Oxygen and carbon isotope patterns archived in shells of the aquatic gastropod Radix - hydrologic and climatic signals across the Tibetan Plateau in sub-monthly resolution JF - Quaternary international : the journal of the International Union for Quaternary Research N2 - The Tibetan Plateau (TP), including its surrounding mountain ranges, represents the largest store of ice outside the polar regions. It hosts numerous lakes as well as the head waters of major Asian rivers, on which billions of people depend, and it is particularly sensitive to climate change. The moisture transport to the TP is controlled by the Indian and Pacific monsoon and the Westerlies. Understanding the evolution of the interaction of these circulation systems requires studies on climate archives in different spatial and temporal contexts. The objective of this study is to learn more about the interannual variability of precipitation patterns across the TP and how different hydrologic systems react to different climatic factors. Aragonite shells of the aquatic gastropod Radix, which is widely distributed in the region, may represent suitable archives for inferring hydrologic and climatic signals in particularly high resolution. Therefore, sclerochronological studies of delta O-18 and delta C-13 ratios in Radix shells from seven lakes were conducted, each representing a different hydrologic and climatic setting, on a transect from the Pamirs across the TP. The shell patterns exhibit an increasing influence of precipitation and a decreasing influence of evaporation on the isotope compositions from west to east. delta O-18 values of shells from lakes on the eastern and central TP (Donggi Cona, Yamdrok Yumco, Tarab Co) mirror monsoon signals, indicated by more negative values and higher variabilities compared to the more western lakes (Karakul, Bangong/Nyak, Manasarovar). In Yadang Co, located on the central southern TP, the monsoon rains did not reach the lake in the sampling year, although it is located in a region which is usually affected by monsoon circulation. The delta O-18 values are used to differentiate the annual hydrological cycle into ice cover period, melt water period, precipitation period and evaporation period. delta C-13 compositions in the shells particularly depend on specific habitats, which vary in biological productivity and in carbon sources. delta O-18 and delta C-13 patterns show a positive covariance in shells originating from large closed basins. The results show that Radix shells mirror general climatic differences between the seven lake regions. These differences reflect both regional and local climate signals in sub-seasonal resolution, without noticeable dependence on the particular lake system. Y1 - 2013 U6 - https://doi.org/10.1016/j.quaint.2012.10.031 SN - 1040-6182 VL - 290 IS - 1 SP - 282 EP - 298 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Costa, Alexandre Cunha A1 - Förster, Saskia A1 - de Araujo, Jose Carlos A1 - Bronstert, Axel T1 - Analysis of channel transmission losses in a dryland river reach in north-eastern Brazil using streamflow series, groundwater level series and multi-temporal satellite data JF - Hydrological processes N2 - Scarcity of hydrological data, especially streamflow discharge and groundwater level series, restricts the understanding of channel transmission losses (TL) in drylands. Furthermore, the lack of information on spatial river dynamics encompasses high uncertainty on TL analysis in large rivers. The objective of this study was to combine the information from streamflow and groundwater level series with multi-temporal satellite data to derive a hydrological concept of TL for a reach of the Middle Jaguaribe River (MJR) in semi-arid north-eastern Brazil. Based on this analysis, we proposed strategies for its modelling and simulation. TL take place in an alluvium, where river and groundwater can be considered to be hydraulically connected. Most losses certainly infiltrated only through streambed and levees and not through the flood plains, as could be shown by satellite image analysis. TL events whose input river flows were smaller than a threshold did not reach the outlet of the MJR. TL events whose input flows were higher than this threshold reached the outlet losing on average 30% of their input. During the dry seasons (DS) and at the beginning of rainy seasons (DS/BRS), no river flow is expected for pre-events, and events have vertical infiltration into the alluvium. At the middle and the end of the rainy seasons (MRS/ERS), river flow sustained by base flow occurs before/after events, and lateral infiltration into the alluvium plays a major role. Thus, the MJR shifts from being a losing river at DS/BRS to become a losing/gaining (mostly losing) river at MRS/ERS. A model of this system has to include the coupling of river and groundwater flow processes linked by a leakage approach. KW - channel transmission losses KW - multi-temporal RapidEye satellite data KW - semi-arid hydrology KW - north-eastern Brazil KW - dryland rivers KW - riveraquifer interaction Y1 - 2013 U6 - https://doi.org/10.1002/hyp.9243 SN - 1099-1085 VL - 27 IS - 7 SP - 1046 EP - 1060 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Romero-Viana, Lidia A1 - Kienel, Ulrike A1 - Wilkes, Heinz A1 - Sachse, Dirk T1 - Growth-dependent hydrogen isotopic fractionation of algal lipid biomarkers in hypersaline Isabel Lake (Mexico) JF - Geochimica et cosmochimica acta : journal of the Geochemical Society and the Meteoritical Society N2 - In this study, we evaluated the potential of the hydrogen isotopic composition of algal lipid biomarkers as a proxy for past hydroclimatic variability in hypersaline Isabel Lake, Mexico (Eastern Pacific). We compared rainfall variability recorded in the region over the last 65 years with changes in delta D values of the most abundant compounds preserved in the uppermost 16 cm of lake sediment. Changes in delta D values of the 1,15-C-32 diol (delta D-diol), a specific biomarker of algal populations, were related to rainfall variability; specifically, n-alkyl diols were more deuterium-enriched (depleted) during wetter (drier) periods. Strikingly, neither the magnitude of lipid biomarker isotopic changes over interannual timescales (of up to 70-80 parts per thousand) nor the direction of that variability can be explained by changes in delta D values of the water source or salinity fluctuations (approximately 30 on the practical salinity scale) controlled by seasonal rainfall. However, changes in sedimentary biomarker composition, higher total organic carbon content and less negative delta C-13 values of the 1,15-C-32 diol indicate enhanced algal growth during wetter periods. We find that these conditions result in less negative delta D values of n-alkyl diols. We hypothesize that due to higher lipid demand during enhanced algal growth, an increasing proportion of hydrogen for lipid synthesis is derived from the cytosol via oxidation of polysaccharides, which may cause a deuterium enrichment of the acetogenic compounds. This study has significant implications for paleohydrological reconstructions using algal lipid delta D values, particularly in highly seasonal environments such as Isabel Lake. In such environments, delta D values of specific algal lipid biomarkers may not record the full seasonal cycle in source water delta D but appear to be mainly controlled by the physiological state of algal populations. Our data provide the first evidence that changes in D/H fractionation due to algal growth conditions can be recorded in sediments. For paleoclimate reconstructions in such environments, algal growth conditions should be constrained with additional proxy data (delta C-13 values of the same biomarkers), as the net D/H fractionation between water and lipids may not have been constant over time. Y1 - 2013 U6 - https://doi.org/10.1016/j.gca.2012.12.017 SN - 0016-7037 VL - 106 IS - 4 SP - 490 EP - 500 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Hamann, Göran A1 - Tronicke, Jens A1 - Steelman, Colby M. A1 - Endres, Anthony L. T1 - Spectral velocity analysis for the determination of ground-wave velocities and their uncertainties in multi-offset GPR data JF - Near surface geophysics N2 - In many hydrological applications, ground-wave velocity measurements are increasingly used to map and monitor shallow soil water content. In this study, we propose an automated spectral velocity analysis method to determine the direct ground-wave (DGW) velocity from common midpoint (CMP) or multi-offset ground-penetrating radar (GPR) data. The method introduced in this paper is a variation of the well-known spectral velocity analysis for seismic and GPR reflection events where velocity spectra are computed using different coherency measures along hyperbolas following the normal moveout model. Here, the unnormalized cross-correlation is computed between waveforms across data gathers that are corrected with a linear moveout equation using a predefined range of velocities. Peaks in the resulting velocity spectra identify linear events in the GPR data gathers like DGW events and allow for estimating the corresponding velocities. In addition to obtaining a DGW velocity measurement, we propose a robust method to estimate the associated velocity uncertainties based on the width of the peak in the calculated velocity spectrum. Our proposed method is tested on synthetic data examples to evaluate the influence of subsurface velocity, surveying geometry and signal frequency on the accuracy of estimated ground-wave velocities. In addition, we investigate the influence of such velocity uncertainties on subsequent soil water content estimates using an established petrophysical relationship. Furthermore, we apply our approach to analyse field data, which were collected across a test site in Canada to monitor a wide range of seasonal soil moisture variations. A comparison between our spectral velocity estimates and results derived from manually picked ground-wave arrivals shows good agreement, which illustrates that our spectral velocity analysis is a feasible tool to analyse DGW arrivals in multi-offset GPR data gathers in an objective and more automated manner. Y1 - 2013 U6 - https://doi.org/10.3997/1873-0604.2012038 SN - 1569-4445 VL - 11 IS - 2 SP - 167 EP - 176 PB - European Association of Geoscientists & Engineers CY - Houten ER - TY - JOUR A1 - Beck, Jan A1 - Holloway, Jeremy D. A1 - Schwanghart, Wolfgang T1 - Undersampling and the measurement of beta diversity JF - Methods in ecology and evolution : an official journal of the British Ecological Society N2 - Beta diversity is a conceptual link between diversity at local and regional scales. Various additional methodologies of quantifying this and related phenomena have been applied. Among them, measures of pairwise (dis)similarity of sites are particularly popular. Undersampling, i.e. not recording all taxa present at a site, is a common situation in ecological data. Bias in many metrics related to beta diversity must be expected, but only few studies have explicitly investigated the properties of various measures under undersampling conditions. On the basis of an empirical data set, representing near-complete local inventories of the Lepidoptera from an isolated Pacific island, as well as simulated communities with varying properties, we mimicked different levels of undersampling. We used 14 different approaches to quantify beta diversity, among them dataset-wide multiplicative partitioning (i.e. true beta diversity') and pairwise site x site dissimilarities. We compared their values from incomplete samples to true results from the full data. We used these comparisons to quantify undersampling bias and we calculated correlations of the dissimilarity measures of undersampled data with complete data of sites. Almost all tested metrics showed bias and low correlations under moderate to severe undersampling conditions (as well as deteriorating precision, i.e. large chance effects on results). Measures that used only species incidence were very sensitive to undersampling, while abundance-based metrics with high dependency on the distribution of the most common taxa were particularly robust. Simulated data showed sensitivity of results to the abundance distribution, confirming that data sets of high evenness and/or the application of metrics that are strongly affected by rare species are particularly sensitive to undersampling. The class of beta measure to be used should depend on the research question being asked as different metrics can lead to quite different conclusions even without undersampling effects. For each class of metric, there is a trade-off between robustness to undersampling and sensitivity to rare species. In consequence, using incidence-based metrics carries a particular risk of false conclusions when undersampled data are involved. Developing bias corrections for such metrics would be desirable. KW - Bray-Curtis KW - Chao KW - Effective number of species KW - Incomplete inventories KW - Jaccard KW - Macrolepidoptera KW - Morisita KW - Morisita-Horn KW - NESS KW - Norfolk Island Y1 - 2013 U6 - https://doi.org/10.1111/2041-210x.12023 SN - 2041-210X VL - 4 IS - 4 SP - 370 EP - 382 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Jagdhuber, Thomas A1 - Hajnsek, Irena A1 - Bronstert, Axel A1 - Papathanassiou, Konstantinos Panagiotis T1 - Soil moisture estimation under low vegetation cover using a multi-angular polarimetric decomposition JF - IEEE transactions on geoscience and remote sensing N2 - The estimation of volumetric soil moisture under low agricultural vegetation from fully polarimetric synthetic aperture radar (SAR) data at L-band using a multi-angular polarimetric decomposition is investigated. Radar polarimetry provides the framework to decompose the backscattered signal into different canonical scattering mechanisms referring to scattering contributions from the underlying soil and the vegetation cover. Multiangular observation diversity further increases the information space for soil moisture inversion enabling higher inversion rates and a stable inversion performance. The developed approach was applied on the multi-angular L-band data set acquired by German Aerospace Center's ESAR sensor as part of the OPAQUE campaign in 2008. The obtained results are compared against ground measurements collected by the OPAQUE team over a variety of vegetated agricultural fields. The validation of the estimated against ground measured soil moisture results in an root mean square error level of 6-8 vol.% including all test fields with a variety of crop types. KW - Multi-angular model-based decomposition KW - polarimetric SAR KW - soil moisture Y1 - 2013 U6 - https://doi.org/10.1109/TGRS.2012.2209433 SN - 0196-2892 VL - 51 IS - 4 SP - 2201 EP - 2215 PB - Inst. of Electr. and Electronics Engineers CY - Piscataway ER - TY - JOUR A1 - Stright, Lisa A1 - Bernhardt, Anne A1 - Boucher, Alexandre T1 - DFTopoSim modeling topographically-controlled deposition of subseismic scale sandstone packages within a mass transport dominated deep-water channel belt JF - Mathematical geosciences : the official journal of the International Association for Mathematical Geosciences N2 - Facies bodies in geostatistical models of deep-water depositional environments generally represent channel-levee-overbank-lobe morphologies. Such models adequately capture one set of the erosional and depositional processes resulting from turbidity currents traveling downslope to the ocean basin floor. However, depositional morphologies diverge from the straight forward channel-levee-overbank-lobe paradigm when the topography of the slope or the shape of the basin impacts the timing and magnitude of turbidity current deposition. Subaqueous mass-transport-deposits (MTDs) present the need for an exception to the channel-levee-overbank-lobe archetype. Irregular surface topography of subaqueous MTDs can play a primary role in controlling sand deposition from turbidity currents. MTD topography creates mini-basins in which sand accumulates in irregularly-shaped deposits. These accumulations are difficult to laterally correlate using well-log data due to their variable and unpredictable shape and size. Prediction is further complicated because sandstone bodies typical of this setting are difficult to resolve in seismic-reflection data. An event-based model is presented, called DFTopoSim, which simulates debris flows and turbidity currents. The accommodation space on top of and between debris flow lobes is filled in by sand from turbidity currents. When applied to a subsurface case in the Molasse Basin of Upper Austria, DFTopoSim predicts sand packages consistent with observations from core, well, and seismic data and the interpretation of the sedimentologic processes. DFTopoSim expands the set of available geostatistical deep-water depositional models beyond the standard channel-levee-overbank-lobe model. KW - Geostatistics KW - Event-based modeling KW - Facies modeling KW - Deep-marine sedimentology KW - Submarine channel Y1 - 2013 U6 - https://doi.org/10.1007/s11004-013-9444-7 SN - 1874-8961 VL - 45 IS - 3 SP - 277 EP - 296 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Negro, Francois A1 - Bousquet, Romain A1 - Vils, Flurin A1 - Pellet, Clara-Marine A1 - Hänggi-Schaub, Jeanette T1 - Thermal structure and metamorphic evolution of the Piemont-Ligurian metasediments in the northern Western Alps JF - Swiss journal of geosciences N2 - In the Western Alps, the Piemont-Ligurian oceanic domain records blueschist to eclogite metamorphic conditions during the Alpine orogeny. This domain is classically divided into two "zones" (Combin and Zermatt-Saas), with contrasting metamorphic evolution, and separated tectonically by the Combin fault. This study presents new metamorphic and temperature (RSCM thermometry) data obtained in Piemont-Ligurian metasediments and proposes a reevaluation of the P-T evolution of this domain. In the upper unit (or "Combin zone") temperatures are in the range of 420-530 A degrees C, with an increase of temperature from upper to lower structural levels. Petrological evidences show that these temperatures are related to the retrograde path and to deformation at greenschist metamorphic conditions. This highlights heating during exhumation of HP metamorphic rocks. In the lower unit (or "Zermatt-Saas zone"), temperatures are very homogeneous in the range of 500-540 A degrees C. This shows almost continuous downward temperature increase in the Piemont-Ligurian domain. The observed thermal structure is interpreted as the result of the upper and lower unit juxtaposition along shear zones at a temperature of similar to 500 A degrees C during the Middle Eocene. This juxtaposition probably occurred at shallow crustal levels (similar to 15-20 km) within a subduction channel. We finally propose that the Piemont-Ligurian Domain should not be viewed as two distinct "zones", but rather as a stack of several tectonic slices. KW - RSCM thermometry KW - Zermatt-Saas KW - Combin KW - Cignana KW - HP and UHP metamorphism Y1 - 2013 U6 - https://doi.org/10.1007/s00015-013-0119-7 SN - 1661-8726 VL - 106 IS - 1 SP - 63 EP - 78 PB - Springer CY - Basel ER - TY - JOUR A1 - Dulanya, Zuze A1 - Reed, Jane M. A1 - Trauth, Martin H. T1 - Mapping changing shorelines in the Malombe and Chiuta lakes of Malawi-environmental effects of recent climatic variations JF - Catena : an interdisciplinary journal of soil science, hydrology, geomorphology focusing on geoecology and landscape evolution N2 - This study examines patterns of climate variability by mapping shoreline changes between 1973 and 2008 for two shallow lakes in Malawi, East Africa. Multi-temporal LANDSAT data covering eight different years within the period of investigation were utilised for lake-area mapping, using image classification techniques. The approach was verified using simple comparisons with local rainfall data and satellite altimetry data. Results indicated that the lake areas varied between the different years investigated and that, although the lakes were affected by the same climate-forcing mechanisms, the individual basin characteristics had a critical effect on their responses. The most likely drivers for the climate-related shoreline variations are the El Nino/Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), causing synchronous changes to the water levels in both lakes, albeit showing differences in climate signal amplification. KW - Lake Malombe KW - Lake Chiuta KW - Lake-area KW - ENSO/IOD Y1 - 2013 U6 - https://doi.org/10.1016/j.catena.2012.10.016 SN - 0341-8162 VL - 104 IS - 10 SP - 111 EP - 119 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Nazarova, Larisa B. A1 - de Hoog, Verena A1 - Hoff, Ulrike A1 - Dirksen, Oleg A1 - Diekmann, Bernhard T1 - Late Holocene climate and environmental changes in Kamchatka inferred from the subfossil chironomid record JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - This study presents a reconstruction of the Late Holocene climate in Kamchatka based on chironomid remains from a 332 cm long composite sediment core recovered from Dvuyurtochnoe Lake (Two-Yurts Lake, TYL) in central Kamchatka. The oldest recovered sediments date to about 4500 cal years BP. Chironomid head capsules from TYL reflect a rich and diverse fauna. An unknown morphotype of Tanytarsini, Tanytarsus type klein, was found in the lake sediments. Our analysis reveals four chironomid assemblage zones reflecting four different climatic periods in the Late Holocene. Between 4500 and 4000 cal years BP, the chironomid composition indicates a high lake level, well-oxygenated lake water conditions and close to modern temperatures (similar to 13 degrees C). From 4000 to 1000 cal years BP, two consecutive warm intervals were recorded, with the highest reconstructed temperature reaching 16.8 degrees C between 3700 and 2800 cal years BP. Cooling trend, started around 1100 cal years BP led to low temperatures during the last stage of the Holocene. Comparison with other regional studies has shown that termination of cooling at the beginning of late Holocene is relatively synchronous in central Kamchatka, South Kurile, Bering and Japanese Islands and take place around 3700 cal years BP. From ca 3700 cal years BP to the last millennium, a newly strengthened climate continentality accompanied by general warming trend with minor cool excursions led to apparent spatial heterogeneity of climatic patterns in the region. Some timing differences in climatic changes reconstructed from chironomid record of TYL sediments and late Holocene events reconstructed from other sites and other proxies might be linked to differences in local forcing mechanisms or caused by the different degree of dating precision, the different temporal resolution, and the different sensitive responses of climate proxies to the climate variations. Further high-resolution stratigraphic studies in this region are needed to understand the spatially complex pattern of climate change in Holocene in Kamchatka and the surrounding region. KW - Kamchatka KW - Holocene KW - Chironomids KW - Palaeoclimate KW - Temperature Y1 - 2013 U6 - https://doi.org/10.1016/j.quascirev.2013.01.018 SN - 0277-3791 VL - 67 IS - 9 SP - 81 EP - 92 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Lück, Erika A1 - Rühlmann, Jörg T1 - Resistivity mapping with GEOPHILUS ELECTRICUS - Information about lateral and vertical soil heterogeneity JF - Geoderma : an international journal of soil science N2 - GEOPHILUS ELECTRICUS (nickname GEOPHILUS) is a novel system for mapping the complex electrical bulk resistivity of soils. Rolling electrodes simultaneously measure amplitude and phase data at frequencies ranging from 1 mHz to 1 kHz. The sensor's design and technical specifications allow for measuring these parameters at five depths of up to ca. 1.5 m. Data inversion techniques can be employed to determine resistivity models instead of apparent values and to image soil layers and their geometry with depth. When used in combination with a global positioning system (GPS) and a suitable cross-country vehicle, it is possible to map about 100 ha/day (assuming 1 data point is recorded per second and the line spacing is 18 m). The applicability of the GEOPHILUS system has been demonstrated on several sites, where soils show variations in texture, stratification, and thus electrical characteristics. The data quality has been studied by comparison with 'static' electrodes, by repeated measurements, and by comparison with other mobile conductivity mapping devices (VERIS3100 and EM38). The high quality of the conductivity data produced by the GEOPHILUS system is evident and demonstrated by the overall consistency of the individual maps, and in the clear stratification also confirmed by independent data. The GEOPHILUS system measures complex values of electrical resistivity in terms of amplitude and phase. Whereas electrical conductivity data (amplitude) are well established in soil science, the interpretation of phase data is a topic of current research. Whether phase data are able to provide additional information depends on the site-specific settings. Here, we present examples, where phase data provide complementary information on man-made structures such as metal pipes and soil compaction. KW - Proximal soil sensing KW - Electrical conductivity KW - Electrical resistivity KW - Phase angle KW - Mapping KW - Soil stratification Y1 - 2013 U6 - https://doi.org/10.1016/j.geoderma.2012.11.009 SN - 0016-7061 VL - 199 SP - 2 EP - 11 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Wiesmeier, Martin A1 - Prietzel, Jörg A1 - Barthold, Frauke Katrin A1 - Spörlein, Peter A1 - Geuss, Uwe A1 - Hangen, Edzard A1 - Reischl, Arthur A1 - Schilling, Bernd A1 - von Lützow, Margit A1 - Kögel-Knabner, Ingrid T1 - Storage and drivers of organic carbon in forest soils of southeast Germany (Bavaria) - Implications for carbon sequestration JF - Forest ecology and management N2 - Temperate forest soils of central Europe are regarded as important pools for soil organic carbon (SOC) and thought to have a high potential for carbon (C) sequestration. However, comprehensive data on total SOC storage, particularly under different forest types, and its drivers is limited. In this study, we analyzed a forest data set of 596 completely sampled soil profiles down to the parent material or to a depth of 1 m within Bavaria in southeast Germany in order to determine representative SOC stocks under different forest types in central Europe and the impact of different environmental parameters. We calculated a total median SOC stock of 9.8 kg m(-2) which is considerably lower compared with many other inventories within central Europe that used modelled instead of measured soil properties. Statistical analyses revealed climate as controlling parameter for the storage of SOC with increasing stocks in cool, humid mountainous regions and a strong decrease in areas with higher temperatures. No significant differences of total SOC storage were found between broadleaf, coniferous and mixed forests. However, coniferous forests stored around 35% of total SOC in the labile organic layer that is prone to human disturbance, forest fires and rising temperatures. In contrast, mixed and broadleaf forests stored the major part of SOC in the mineral soil. Moreover, these two forest types showed unchanged or even slightly increased mineral SOC stocks with higher temperatures, whereas SOC stocks in mineral soils under coniferous forest were distinctly lower. We conclude that mixed and broadleaf forests are more advantageous for C sequestration than coniferous forests. An intensified incorporation of broadleaf species in extent coniferous forests of Bavaria would prevent substantial SOC losses as a result of rising temperatures in the course of climate change. KW - Tree species effect KW - Soil organic matter KW - Climate change KW - Forest management Y1 - 2013 U6 - https://doi.org/10.1016/j.foreco.2013.01.025 SN - 0378-1127 VL - 295 IS - 10 SP - 162 EP - 172 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Amour, Frederic A1 - Mutti, Maria A1 - Christ, Nicolas A1 - Immenhauser, Adrian A1 - Benson, Gregory S. A1 - Agar, Susan M. A1 - Tomas, Sara A1 - Kabiri, Lahcen T1 - Outcrop analog for an oolitic carbonate ramp reservoir a scale-dependent geologic modeling approach based on stratigraphic hierarchy JF - AAPG bulletin N2 - Considerable effort has been devoted to the development of simulation algorithms for facies modeling, whereas a discussion of how to combine those techniques has not existed. The integration of multiple geologic data into a three-dimensional model, which requires the combination of simulation techniques, is yet a current challenge for reservoir modeling. This article presents a thought process that guides the acquisition and modeling of geologic data at various scales. Our work is based on outcrop data collected from a Jurassic carbonate ramp located in the High Atlas mountain range of Morocco. The study window is 1 km (0.6 mi) wide and 100 m (328.1 ft) thick. We describe and model the spatial and hierarchical arrangement of carbonate bodies spanning from largest to smallest: (1) stacking pattern of high-frequency depositional sequences, (2) facies association, and (3) lithofacies. Five sequence boundaries were modeled using differential global position system mapping and light detection and ranging data. The surface-based model shows a low-angle profile with modest paleotopographic relief at the inner-to-middle ramp transition. Facies associations were populated using truncated Gaussian simulation to preserve ordered trends between the inner, middle, and outer ramps. At the lithofacies scale, field observations and statistical analysis show a mosaiclike distribution that was simulated using a fully stochastic approach with sequential indicator simulation. This study observes that the use of one single simulation technique is unlikely to correctly model the natural patterns and variability of carbonate rocks. The selection and implementation of different techniques customized for each level of the stratigraphic hierarchy will provide the essential computing flexibility to model carbonate settings. This study demonstrates that a scale-dependent modeling approach should be a common procedure when building subsurface and outcrop models. Y1 - 2013 U6 - https://doi.org/10.1306/10231212039 SN - 0149-1423 VL - 97 IS - 5 SP - 845 EP - 871 PB - American Association of Petroleum Geologists CY - Tulsa ER - TY - JOUR A1 - Anoop, Ambili A1 - Prasad, S. A1 - Plessen, Birgit A1 - Basavaiah, Nathani A1 - Gaye, B. A1 - Naumann, R. A1 - Menzel, P. A1 - Weise, S. A1 - Brauer, Achim T1 - Palaeoenvironmental implications of evaporative gaylussite crystals from Lonar Lake, central India JF - Journal of quaternary science N2 - We have undertaken petrographic, mineralogical, geochemical and isotopic investigations on carbonate minerals found within a 10-m-long core from Lonar Lake, central India, with the aim of evaluating their potential as palaeoenvironmental proxies. The core encompasses the entire Holocene and is the first well-dated high-resolution record from central India. While calcite and/or aragonite were found throughout the core, the mineral gaylussite was found only in two specific intervals (46303890 and 2040560 cal a BP). Hydrochemical and isotope data from inflowing streams and lake waters indicate that evaporitic processes play a dominant role in the precipitation of carbonates within this lake. Isotopic (18O and 13C) studies on the evaporative gaylussite crystals and residual bulk carbonates (calcite) from the long core show that evaporation is the major control on 18O enrichment in both the minerals. However, in case of 13C additional mechanisms, for example methanogenesis (gaylussite) and phytoplankton productivity (calcium carbonate), play an additional important role in some intervals. We also discuss the relevance of our investigation for palaeoclimate reconstruction and late Holocene monsoon variability. KW - evaporites KW - gaylussite KW - isotopes KW - Lonar Lake KW - monsoon Y1 - 2013 U6 - https://doi.org/10.1002/jqs.2625 SN - 0267-8179 VL - 28 IS - 4 SP - 349 EP - 359 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Miller, Scott R. A1 - Sak, Peter B. A1 - Kirby, Eric A1 - Bierman, Paul R. T1 - Neogene rejuvenation of central appalachian topography evidence for differential rock uplift from stream profiles and erosion rates JF - Earth & planetary science letters N2 - The persistence of topography within ancient orogens remains one of the outstanding questions in landscape evolution. In the eastern North American Appalachians, this question is manifest in the outstanding problem of whether topographic relief is in a quasi-equilibrium state, decaying slowly over many millennia, or whether relief has increased during the late Cenozoic. Here we present quantitative geomorphic data from the nonglaciated portion of the Susquehanna River drainage basin that provide insight into these end-member models. Analysis of channel profiles draining upland catchments in the northern Valley and Ridge, Appalachian Plateau, Blue Ridge, and Piedmont provinces reveals that a large number of streams have well defined knickpoints clustered at 300-600 m elevation but not systematically associated with transitions from weak to resistant substrate. Cosmogenic Be-10 inventories of modern stream sediment indicate that erosion rates are spatially variable, ranging from similar to 5-30 m/Myr above knickpoints to similar to 50-100 m/Myr below knickpoints. Overall, channel gradients, normalized for drainage area, scale linearly with catchment-averaged erosion rates. Collectively, regionally consistent spatial relationships among erosion rate, channel steepness, and knickpoints reveal an ongoing wave of transient channel adjustment to a change in relative base level. Reconstructions of relict channel profiles above knickpoints suggest that higher rates of incision are associated with similar to 100-150 m of relative base level fall that accompanied epierogenic rock uplift rather than a change to a more erosive climate or drainage reorganization. Channel response timescales imply that the onset of relative base level change predates similar to 3.5 Ma and may have begun as early as similar to 15 Ma. We suggest that adjustment of the channel network was likely driven by changes in mantle dynamics along the eastern seaboard of North America during the Neogene. KW - Appalachian Mountains KW - stream profile KW - knickpoint KW - transient erosion KW - cosmogenic nuclides Y1 - 2013 U6 - https://doi.org/10.1016/j.epsl.2013.04.007 SN - 0012-821X SN - 1385-013X VL - 369 IS - 2 SP - 1 EP - 12 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Baroni, Gabriele A1 - Ortuani, B. A1 - Facchi, A. A1 - Gandolfi, C. T1 - The role of vegetation and soil properties on the spatio-temporal variability of the surface soil moisture in a maize-cropped field JF - Journal of hydrology N2 - Soil moisture dynamics are affected by complex interactions among several factors. Understanding the relative importance of these factors is still an important challenge in the study of water fluxes and solute transport in unsaturated media. In this study, the spatio-temporal variability of surface soil moisture was investigated in a 10 ha flat cropped field located in northern Italy. Soil moisture was measured on a regular 50 x 50 m grid on seven dates during the growing season. For each measurement campaign, the spatial variability of the soil moisture was compared with the spatial variability of the soil texture and crop properties. In particular, to better understand the role of the vegetation, the spatio-temporal variability of two different parameters - leaf area index and crop height - was monitored on eight dates at different crop development stages. Statistical and geostatistical analysis was then applied to explore the interactions between these variables. In agreement with other studies, the results show that the soil moisture variability changes according to the average value within the field, with the standard deviation reaching a maximum value under intermediate mean soil moisture conditions and the coefficient of variation decreasing exponentially with increasing mean soil moisture. The controls of soil moisture variability change according to the average soil moisture within the field. Under wet conditions, the spatial distribution of the soil moisture reflects the variability of the soil texture. Under dry conditions, the spatial distribution of the soil moisture is affected mostly by the spatial variability of the vegetation. The interaction between these two factors is more important under intermediate soil moisture conditions. These results confirm the importance of considering the average soil moisture conditions within a field when investigating the controls affecting the spatial variability of soil moisture. This study highlights the importance of considering the spatio-temporal variability of the vegetation in investigating soil moisture dynamics, especially under intermediate and dry soil moisture conditions. The results of this study have important implications in different hydrological applications, such as for sampling design, ranking stability application, indirect measurements of soil properties and model parameterisation. KW - Soil moisture KW - Spatio-temporal variability KW - Controlling factors KW - Principal component analysis KW - Geostatistics KW - Agricultural field Y1 - 2013 U6 - https://doi.org/10.1016/j.jhydrol.2013.03.007 SN - 0022-1694 SN - 1879-2707 VL - 489 IS - 7 SP - 148 EP - 159 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Gao, Mingxing A1 - Zeilinger, Gerold A1 - Xu, Xiwei A1 - Wang, Qingliang A1 - Hao, Ming T1 - DEM and GIS analysis of geomorphic indices for evaluating recent uplift of the northeastern margin of the Tibetan Plateau, China JF - Geomorphology : an international journal on pure and applied geomorphology N2 - The northeastern margin of the Tibetan Plateau is a tectonically active region consisting of a series of faults with bounded intermountain basins and is located in the transition zone between the Tibetan Plateau and the Loess Plateau. Active deformation that may affect the topography in this region can be quantified using geomorphic indices. Therefore, we applied geomorphic indices such as the hypsometric integral and the stream length gradient index to infer neo-tectonics in the northeastern margin of the Tibetan Plateau. Different time-scaled geodetic leveling data and river incision rates were also integrated into the investigation. The results show that the hypsometric integrals are not significantly affected by lithology but spatially correspond to the hanging walls of thrust faults. The hypsometric integrals are also positively correlated with the leveling data. Although the stream length gradient index is influenced by lithology, its most pronounced anomalies of the stream length gradient are associated with the thrust faults. Consequently, the uplift in the northeast margin of the Tibetan Plateau appeared to be concentrated along the hanging walls of the thrust faults. KW - Tectonic geomorphology KW - Hypsometry analysis KW - Stream length gradient KW - Active tectonics KW - Leveling data KW - Tibetan Plateau Y1 - 2013 U6 - https://doi.org/10.1016/j.geomorph.2013.02.008 SN - 0169-555X VL - 190 IS - 20 SP - 61 EP - 72 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Pradhan, Prajal A1 - Reusser, Dominik Edwin A1 - Kropp, Jürgen T1 - Embodied greenhouse gas emissions in Diets JF - PLoS one N2 - Changing food consumption patterns and associated greenhouse gas (GHG) emissions have been a matter of scientific debate for decades. The agricultural sector is one of the major GHG emitters and thus holds a large potential for climate change mitigation through optimal management and dietary changes. We assess this potential, project emissions, and investigate dietary patterns and their changes globally on a per country basis between 1961 and 2007. Sixteen representative and spatially differentiated patterns with a per capita calorie intake ranging from 1,870 to >3,400 kcal/day were derived. Detailed analyses show that low calorie diets are decreasing worldwide, while in parallel diet composition is changing as well: a discernable shift towards more balanced diets in developing countries can be observed and steps towards more meat rich diets as a typical characteristics in developed countries. Low calorie diets which are mainly observable in developing countries show a similar emission burden than moderate and high calorie diets. This can be explained by a less efficient calorie production per unit of GHG emissions in developing countries. Very high calorie diets are common in the developed world and exhibit high total per capita emissions of 3.7-6.1 kg CO2eq./day due to high carbon intensity and high intake of animal products. In case of an unbridled demographic growth and changing dietary patterns the projected emissions from agriculture will approach 20 Gt CO2eq./yr by 2050. Y1 - 2013 U6 - https://doi.org/10.1371/journal.pone.0062228 SN - 1932-6203 VL - 8 IS - 5 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Dallmeyer, A. A1 - Claussen, Martin A1 - Wang, Y. A1 - Herzschuh, Ulrike T1 - Spatial variability of Holocene changes in the annual precipitation pattern a model-data synthesis for the Asian monsoon region JF - Climate dynamics : observational, theoretical and computational research on the climate system N2 - This study provides a detailed analysis of the mid-Holocene to present-day precipitation change in the Asian monsoon region. We compare for the first time results of high resolution climate model simulations with a standardised set of mid-Holocene moisture reconstructions. Changes in the simulated summer monsoon characteristics (onset, withdrawal, length and associated rainfall) and the mechanisms causing the Holocene precipitation changes are investigated. According to the model, most parts of the Indian subcontinent received more precipitation (up to 5 mm/day) at mid-Holocene than at present-day. This is related to a stronger Indian summer monsoon accompanied by an intensified vertically integrated moisture flux convergence. The East Asian monsoon region exhibits local inhomogeneities in the simulated annual precipitation signal. The sign of this signal depends on the balance of decreased pre-monsoon and increased monsoon precipitation at mid-Holocene compared to present-day. Hence, rainfall changes in the East Asian monsoon domain are not solely associated with modifications in the summer monsoon circulation but also depend on changes in the mid-latitudinal westerly wind system that dominates the circulation during the pre-monsoon season. The proxy-based climate reconstructions confirm the regional dissimilarities in the annual precipitation signal and agree well with the model results. Our results highlight the importance of including the pre-monsoon season in climate studies of the Asian monsoon system and point out the complex response of this system to the Holocene insolation forcing. The comparison with a coarse climate model simulation reveals that this complex response can only be resolved in high resolution simulations. KW - Asian monsoon KW - Holocene KW - Precipitation KW - Climate modelling KW - Moisture reconstructions Y1 - 2013 U6 - https://doi.org/10.1007/s00382-012-1550-6 SN - 0930-7575 SN - 1432-0894 VL - 40 IS - 11-12 SP - 2919 EP - 2936 PB - Springer CY - New York ER - TY - JOUR A1 - Cesca, Simone A1 - Braun, Thomas A1 - Maccaferri, Francesco A1 - Passarelli, Luigi A1 - Rivalta, Eleonora A1 - Dahm, Torsten T1 - Source modelling of the M5-6 Emilia-Romagna, Italy, earthquakes (2012 May 20-29) JF - Geophysical journal international N2 - On 2012 May 20 and 29, two damaging earthquakes with magnitudes M-w 6.1 and 5.9, respectively, struck the Emilia-Romagna region in the sedimentary Po Plain, Northern Italy, causing 26 fatalities, significant damage to historical buildings and substantial impact to the economy of the region. The earthquake sequence included four more aftershocks with M-w, >= 5.0, all at shallow depths (about 7-9 km), with similar WNW-ESE striking reverse mechanism. The timeline of the sequence suggests significant static stress interaction between the largest events. We perform here a detailed source inversion, first adopting a point source approximation and considering pure double couple and full moment tensor source models. We compare different extended source inversion approaches for the two largest events, and find that the rupture occurred in both cases along a subhorizontal plane, dipping towards SSW Directivity is well detected for the May 20 main shock, indicating that the rupture propagated unilaterally towards SE. Based on the focal mechanism solution, we further estimate the co-seismic static stress change induced by the May 20 event. By using the rate-and-state model and a Poissonian earthquake occurrence, we infer that the second largest event of May 29 was induced with a probability in the range 0.2-0.4. This suggests that the segment of fault was already prone to rupture. Finally, we estimate peak ground accelerations for the two main events as occurred separately or simultaneously. For the scenario involving hypothetical rupture areas of both main events, we estimate M-w = 6.3 and an increase of ground acceleration by 50 per cent. The approach we propose may help to quantify rapidly which regions are invested by a significant increase of the hazard, bearing the potential for large aftershocks or even a second main shock. KW - Earthquake dynamics KW - Earthquake source observations Y1 - 2013 U6 - https://doi.org/10.1093/gji/ggt069 SN - 0956-540X VL - 193 IS - 3 SP - 1658 EP - 1672 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Maghsoudi, Samira A1 - Cesca, Simone A1 - Hainzl, Sebastian A1 - Kaiser, Diethelm A1 - Becker, Dirk A1 - Dahm, Torsten T1 - Improving the estimation of detection probability and magnitude of completeness in strongly heterogeneous media, an application to acoustic emission (AE) JF - Geophysical journal international N2 - Reliable estimations of magnitude of completeness (M-c) are essential for a correct interpretation of seismic catalogues. The spatial distribution of M-c may be strongly variable and difficult to assess in mining environments, owing to the presence of galleries, cavities, fractured regions, porous media and different mineralogical bodies, as well as in consequence of inhomogeneous spatial distribution of the seismicity. We apply a 3-D modification of the probabilistic magnitude of completeness (PMC) method, which relies on the analysis of network detection capabilities. In our approach, the probability to detect an event depends on its magnitude, source receiver Euclidian distance and source receiver direction. The suggested method is proposed for study of the spatial distribution of the magnitude of completeness in a mining environment and here is applied to a 2-months acoustic emission (AE) data set recorded at the Morsleben salt mine, Germany. The dense seismic network and the large data set, which includes more than one million events, enable a detailed testing of the method. This method is proposed specifically for strongly heterogeneous media. Besides, it can also be used for specific network installations, with sensors with a sensitivity, dependent on the direction of the incoming wave (e.g. some piezoelectric sensors). In absence of strong heterogeneities, the standards PMC approach should be used. We show that the PMC estimations in mines strongly depend on the source receiver direction, and cannot be correctly accounted using a standard PMC approach. However, results can be improved, when adopting the proposed 3-D modification of the PMC method. Our analysis of one central horizontal and vertical section yields a magnitude of completeness of about M-c approximate to 1 (AE magnitude) at the centre of the network, which increases up to M-c approximate to 4 at further distances outside the network; the best detection performance is estimated for a NNE-SSE elongated region, which corresponds to the strike direction of the low-attenuating salt body. Our approach provides us with small-scale details about the capability of sensors to detect an earthquake, which can be linked to the presence of heterogeneities in specific directions. Reduced detection performance in presence of strong structural heterogeneities (cavities) is confirmed by synthetic waveform modelling in heterogeneous media. KW - Seismic attenuation KW - Statistical seismology Y1 - 2013 U6 - https://doi.org/10.1093/gji/ggt049 SN - 0956-540X VL - 193 IS - 3 SP - 1556 EP - 1569 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Uhlmann, Manuela A1 - Korup, Oliver A1 - Huggel, Christian A1 - Fischer, Luzia A1 - Kargel, Jeffrey S. T1 - Supra-glacial deposition and flux of catastrophic rock-slope failure debris, south-central Alaska JF - Earth surface processes and landforms : the journal of the British Geomorphological Research Group N2 - The ongoing debate over the effects of global environmental change on Earth's cryosphere calls for detailed knowledge about process rates and their variability in cold environments. In this context, appraisals of the coupling between glacier dynamics and para-glacial erosion rates in tectonically active mountains remain rare. We contribute to filling this knowledge gap and present an unprecedented regional-scale inventory of supra-glacial sediment flux and hillslope erosion rates inferred from an analysis of 123 large (> 0 center dot 1km2) catastrophic bedrock landslides that fell onto glaciers in the Chugach Mountains, Alaska, as documented by satellite images obtained between 1972 to 2008. Assuming these supra-glacial landslide deposits to be passive strain markers we infer minimum decadal-scale sediment yields of 190 to 7400tkm-2yr-1 for a given glacier-surface cross-section impacted by episodic rock-slope failure. These rates compare to reported fluvial sediment yields in many mountain rivers, but are an order of magnitude below the extreme sediment yields measured at the snouts of Alaskan glaciers, indicating that the bulk of debris discharged derives from en-glacial, sub-glacial or ice-proximal sources. We estimate an average minimum para-glacial erosion rate by large, episodic rock-slope failures at 0 center dot 5-0 center dot 7mmyr-1 in the Chugach Mountains over a 50-yr period, with earthquakes likely being responsible for up to 73% of this rate. Though ranking amongst the highest decadal landslide erosion rates for this size of study area worldwide, our inferred rates of hillslope erosion in the Chugach Mountains remain an order of magnitude below the pace of extremely rapid glacial sediment export and glacio-isostatic surface uplift previously reported from the region. KW - glacier KW - landslide KW - erosion rate KW - sediment yield KW - Alaska Y1 - 2013 U6 - https://doi.org/10.1002/esp.3311 SN - 0197-9337 VL - 38 IS - 7 SP - 675 EP - 682 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Vormoor, Klaus Josef A1 - Skaugen, Thomas T1 - Temporal disaggregation of daily temperature and precipitation grid data for Norway JF - Journal of hydrometeorology N2 - This paper presents a simple approach for the temporal disaggregation from daily to 3-hourly observed gridded temperature and precipitation (1 x 1km(2)) on the national scale. The intended use of the disaggregated 3-hourly data is to recalibrate the hydrological model currently used by the Norwegian Water Resources and Energy Directorate (NVE) for daily flood forecasting. By adapting the hydrological model to a 3-hourly temporal scale, the flood forecasting can benefit from available meteorological forecasts with finer temporal resolution and can better represent critical events of short duration and at small spatial scales. By consulting the temporal patterns of a High-Resolution Limited-Area Model (HIRLAM) hindcast series for northern Europe with an hourly temporal and a 0.1 degrees spatial resolution, existing daily 1 x 1km(2) grids for temperature and precipitation covering all of Norway (the seNorge data) were disaggregated into 3-hourly values for the time period September 1957 to December 2010. For the period 2000-05, the disaggregated 3-hourly temperature and precipitation data are validated against observed values from five meteorological stations and against 3-hourly data from the HIRLAM hindcast and daily seNorge data simply split into eight fractions. The results show that the disaggregated data perform best with anomaly correlation coefficients between 0.89 and 0.92 for temperature. With regard to precipitation, the disaggregated data also provide the highest correlations and the lowest errors. In addition, the disaggregated data prove to be best in estimating intervals without precipitation and tend to be most appropriate in estimating extreme precipitation with low occurrence probability (<20%). Y1 - 2013 U6 - https://doi.org/10.1175/JHM-D-12-0139.1 SN - 1525-755X VL - 14 IS - 3 SP - 989 EP - 999 PB - American Meteorological Soc. CY - Boston ER - TY - JOUR A1 - Walter, Marius J. A1 - Trauth, Martin H. T1 - A MATLAB based orientation analysis of Acheulean handaxe accumulations in Olorgesailie and Kariandusi, Kenya Rift JF - Journal of human evolution N2 - The Pleistocene archeological record in East Africa has revealed unusual accumulations of Acheulean handaxes at prehistoric sites. In particular, there has been intensive debate concerning whether the artifact accumulation at the Middle Pleistocene Olorgesailie (Southern Kenya Rift) and Kariandusi (Central Kenya Rift) sites were a result of fluvial reworking or of in situ deposition by hominids. We used a two-step approach to test the hypothesis of fluvial reworking. Firstly, the behavior of handaxes in water currents was investigated in a current flume and the flow threshold required to reorientate the handaxes was determined. The results of these experiments suggested that, in relatively high energy and non-steady flow conditions, handaxes will reorientate themselves perpendicular to the current direction. Secondly, an automated image analysis routine was developed and applied to archeological plans from three Acheulean sites, two at Olorgesailie and one at Kariandusi, in order to determine the orientations of the handaxes. A Rayleigh test was then applied to the orientation data to test for a preferred orientation. The results revealed that the handaxes at the Upper Kariandusi Site and the Olorgesailie Main Site Mid Trench had a preferential orientation, suggesting reworking by a paleocurrent. The handaxes from the Olorgesailie Main Site H/6A, however, appeared to be randomly oriented and in situ deposition by the producers therefore remains a possibility. KW - Excavation plan KW - Artifact KW - Flume channel KW - Shape detection KW - Rayleigh test Y1 - 2013 U6 - https://doi.org/10.1016/j.jhevol.2013.02.011 SN - 0047-2484 VL - 64 IS - 6 SP - 569 EP - 581 PB - Elsevier CY - London ER - TY - JOUR A1 - Thiede, Rasmus Christoph A1 - Ehlers, Todd T1 - Large spatial and temporal variations in Himalayan denudation JF - Earth & planetary science letters N2 - In the last decade growing interest has emerged in quantifying the spatial and temporal variations in mountain building. Until recently, insufficient data have been available to attempt such a task at the scale of large orogens such as the Himalaya. The Himalaya accommodates ongoing convergence between India and Eurasia and is a focal point for studying orogen evolution and hypothesized interactions between tectonics and climate. Here we integrate 1126 published bedrock mineral cooling ages with a transient 1D Monte-Carlo thermal-kinematic erosion model to quantify the denudation histories along similar to 2700 km of the Himalaya. The model free parameter is a temporally variable denudation rate from 50 Ma to present. Thermophysical material properties and boundary conditions were tuned to individual study areas. Monte-Carlo simulations were conducted to identify the range of denudation histories that can reproduce the observed cooling ages. Results indicate large temporal and spatial variations in denudation and these are resolvable across different tectonic units of the Himalaya. More specifically, across > 1000 km of the southern Greater Himalaya denudation rates were highest (similar to 1.5-3 mm/yr) between similar to 10 and 2 Ma and lower (0.5-2.6 mm/yr) over the last 2 My. These differences are best determined in the NW-Himalaya. In contrast to this, across the similar to 2500 km length of the northern Greater Himalaya denudation rates vary over length scales of similar to 300-1700 km. Slower denudation (<1 mm/yr) occurred between 10 and 4 Ma followed by a large increase (1.2-2.6 mm/yr) in the last similar to 4 Ma. We find that only the southern Greater Himalayan Sequence clearly supports a continuous co-evolution of tectonics, climate and denudation. Results from the higher elevation northern Greater Himalaya suggest either tectonic driven variations in denudation due to a ramp-flat geometry in the main decollement and/or recent glacially enhanced denudation. KW - Himalaya KW - exhumation KW - low temperature chronology KW - thermal modeling KW - erosion Y1 - 2013 U6 - https://doi.org/10.1016/j.epsl.2013.03.004 SN - 0012-821X VL - 371 IS - 2 SP - 278 EP - 293 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Thiede, Rasmus Christoph A1 - Sobel, Edward A1 - Chen, Jie A1 - Schoenbohm, Lindsay M. A1 - Stockli, Daniel F. A1 - Sudo, Masafumi A1 - Strecker, Manfred T1 - Late Cenozoic extension and crustal doming in the India-Eurasia collision zone new thermochronologic constraints from the NE Chinese Pamir JF - Tectonics N2 - The northward motion of the Pamir indenter with respect to Eurasia has resulted in coeval thrusting, strike-slip faulting, and normal faulting. The eastern Pamir is currently deformed by east-west oriented extension, accompanied by uplift and exhumation of the Kongur Shan (7719m) and Muztagh Ata (7546m) gneiss domes. Both domes are an integral part of the footwall of the Kongur Shan extensional fault system (KES), a 250 km long, north-south oriented graben. Why active normal faulting within the Pamir is primarily localized along the KES and not distributed more widely throughout the orogen has remained unclear. In addition, relatively little is known about how deformation has evolved throughout the Cenozoic, despite refined estimates on present-day crustal deformation rates and microseismicity, which indicate where crustal deformation is presently being accommodated. To better constrain the spatiotemporal evolution of faulting along the KES, we present 39 new apatite fission track, zircon U-Th-Sm/He, and Ar-40/Ar-39 cooling ages from a series of footwall transects along the KES graben shoulder. Combining these data with present-day topographic relief, 1-D thermokinematic and exhumational modeling documents successive stages, rather than synchronous deformation and gneiss dome exhumation. While the exhumation of the Kongur Shan commenced during the late Miocene, extensional processes in the Muztagh Ata massif began earlier and have slowed down since the late Miocene. We present a new model of synorogenic extension suggesting that thermal and density effects associated with a lithospheric tear fault along the eastern margin of the subducting Alai slab localize extensional upper plate deformation along the KES and decouple crustal motion between the central/western Pamir and eastern Pamir/Tarim basin. KW - Pamir KW - gneiss domes KW - collision KW - extension KW - thermochronology KW - exhumation Y1 - 2013 U6 - https://doi.org/10.1002/tect.20050 SN - 0278-7407 VL - 32 IS - 3 SP - 763 EP - 779 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Macaulay, Euan A. A1 - Sobel, Edward A1 - Mikolaichuk, Alexander A1 - Landgraf, Angela A1 - Kohn, Barry A1 - Stuart, Finlay T1 - Thermochronologic insight into late Cenozoic deformation in the basement-cored Terskey Range, Kyrgyz Tien Shan JF - Tectonics N2 - Basement-cored ranges formed by reverse faulting within intracontinental mountain belts are often composed of poly-deformed lithologies. Geological data capable of constraining the timing, magnitude, and distribution of the most recent deformational phase are usually missing in such ranges. In this paper, we present new low temperature thermochronological and geological data from a transect through the basement-cored Terskey Range, located in the Kyrgyz Tien Shan. Using these data, we are able to investigate the range's late Cenozoic deformation for the first time. Displacements on reactivated faults are constrained and deformation of thermochronologically derived structural markers is assessed. These structural markers postdate the earlier deformational phases, providing the only record of Cenozoic deformation and of the reactivation of structures within the Terskey Range. Overall, these structural markers have a southern inclination, interpreted to reflect the decreasing inclination of the reverse fault bounding the Terskey Range. Our thermochronological data are also used to investigate spatial and temporal variations in the exhumation of the Terskey Range, identifying a three-stage Cenozoic exhumation history: (1) virtually no exhumation in the Paleogene, (2) increase to slightly higher exhumation rates at similar to 26-20Ma, and (3) significant increase in exhumation starting at similar to 10Ma. KW - Thermochronology KW - Basement-cored ranges KW - Tien Shan KW - Structural geology Y1 - 2013 U6 - https://doi.org/10.1002/tect.20040 SN - 0278-7407 VL - 32 IS - 3 SP - 487 EP - 500 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Loebens, Stefan A1 - Sobel, Edward A1 - Bense, Frithjof A. A1 - Wemmer, Klaus A1 - Dunkl, Istvan A1 - Siegesmund, Siegfried T1 - Refined exhumation history of the northern Sierras Pampeanas, Argentina JF - Tectonics N2 - The Sierra de Aconquija and Cumbres Calchaquies in the thick-skinned northern Sierras Pampeanas, NW Argentina present an ideal setting to investigate the tectonically and erosionally controlled exhumation and uplift history of mountain ranges using thermochronological methods. Although these ranges are located along strike of one another, their spatiotemporal evolution varies significantly. Integrating modeled cooling histories constrained by K-Ar ages of muscovite and biotite, apatite fission track data as well as (U-Th)/He measurement of zircon and apatite reveal the structural evolution of these ranges beginning in the late stage of the Paleozoic Famatinian Orogeny. Following localized rift-related exhumation in the central part of the study area and slow erosion elsewhere, growth of the modern topography commenced in the Cenozoic during Andean deformation. The main activity occurred during the late Miocene, with varying magnitudes of rock uplift, surface uplift, and exhumation in the two mountain ranges. The Cumbres Calchaquies is characterized by a total of 5-7km of vertical rock uplift, around 3km of crestal surface uplift, and a maximum exhumation of 2-4km since that time. The Sierra de Aconquija experienced 10-13km of vertical rock uplift, similar to 4-5km of peak surface uplift, and 6-8km of exhumation since around 9Ma. Much of this exhumation occurred along a previously poorly recognized fault. Miocene reactivation of Cretaceous rift structures may explain along-strike variations within these ranges. Dating of sedimentary samples from adjacent basins supports the evolutionary model developed for the mountain ranges. KW - Thermochronology KW - Sierras Pampeanas KW - thermal modeling KW - exhumation and uplift Y1 - 2013 U6 - https://doi.org/10.1002/tect.20038 SN - 0278-7407 VL - 32 IS - 3 SP - 453 EP - 472 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Oberhänsli, Roland T1 - High-Pressure - Low-temperature evolution in the Indus-Tsangpo suture along the Kohistan Arc (Kaghan Valley, NE Pakistan) JF - Episodes : journal of international geosciences N2 - North of Naran in the Kaghan Valley (NE Pakistan), the metabasites of the melange units lying below the Kohistan Arc, contain glaucophane. Typically they reflect blueschist-metamorphic conditions (0.7 GPa, 400 degrees C). Associated graphite-rich metapelites with quartz veins underwent upper greenschist to amphibolite conditions. Near Naran we observed in quartz grains of type 3 veins first minute relics of Fe-Mg carpholite indicating earlier blueschist metamorphic conditions. P-T estimates indicate 1.2-1.6 GPa at 380-410 degrees C, pressure and temperature values typical for blueschist metamorphic conditions. Changes in mineral assemblages and abundant sudoite component in associated chlorite point to a pressure drop after peak I conditions. We assign the observed changes to peak I conditions occurring during a Cretaceous subduction event. Temperatures estimated with Raman graphite-thermometry clearly indicate a significant subsequent rise of post-peak I temperatures up to 500 degrees C. This is compatible with the amphibolite peak II assigned to the Tertiary continental collision that leads to subduction of the Indian Plate and ultra-high-pressure metamorphism. During subduction the blueschist metamorphic metapelites underwent dehydration, which caused alteration in the overlying lithospheric mantle. In a hydrated lithospheric mantle density is significantly reduced which enhanced subduction of continental crust in the Higher Himalaya. This P-T evolution is typical for a collision orogen with a high plateau but remarkably contrasting findings from Eastern Anatolia, where plateau building is in "statu nascendi" (e.g., Oberhänsli et al., 2010). Y1 - 2013 SN - 0705-3797 VL - 36 IS - 2 SP - 87 EP - 93 PB - Geological Society of India CY - Bangalore ER - TY - JOUR A1 - Lambert, Ian A1 - Durrheim, Ray A1 - Godoy, Marcio A1 - Kota, Mxolisi A1 - Leahy, Pat A1 - Ludden, John A1 - Nickless, Edmund A1 - Oberhänsli, Roland A1 - Anjian, Wang A1 - Williams, Neil T1 - Resourcing future generations a proposed new IUGS initiative JF - Episodes : journal of international geosciences Y1 - 2013 SN - 0705-3797 VL - 36 IS - 2 SP - 82 EP - 86 PB - Geological Society of India CY - Bangalore ER - TY - JOUR A1 - Mohr, Christian Heinrich A1 - Coppus, Ruben A1 - Iroume, Andres A1 - Huber, Anton A1 - Bronstert, Axel T1 - Runoff generation and soil erosion processes after clear cutting JF - Journal of geophysical research : Earth surface N2 - Timber harvesting by clear cutting is known to impose environmental impacts, including severe disturbance of the soil hydraulic properties which intensify the frequency and magnitude of surface runoff and soil erosion. However, it remains unanswered if harvest areas act as sources or sinks for runoff and soil erosion and whether such behavior operates in a steady state or evolves through time. For this purpose, 92 small-scale rainfall simulations of different intensities were carried out under pine plantation conditions and on two clear-cut harvest areas of different age. Nonparametrical Random Forest statistical models were set up to quantify the impact of environmental variables on the hydrological and erosion response. Regardless of the applied rainfall intensity, runoff always initiated first and yielded most under plantation cover. Counter to expectations, infiltration rates increased after logging activities. Once a threshold rainfall intensity of 20mm/h was exceeded, the younger harvest area started to act as a source for both runoff and erosion after connectivity was established, whereas it remained a sink under lower applied rainfall intensities. The results suggest that the impact of microtopography on surface runoff connectivity and water-repellent properties of the topsoil act as first-order controls for the hydrological and erosion processes in such environments. Fast rainfall-runoff response, sediment-discharge-hystereses, and enhanced postlogging groundwater recharge at catchment scale support our interpretation. At the end, we show the need to account for nonstationary hydrological and erosional behavior of harvest areas, a fact previously unappreciated in predictive models. KW - infiltration KW - runoff KW - erosion KW - connectivity KW - rainfall simulation KW - catchment Y1 - 2013 U6 - https://doi.org/10.1002/jgrf.20047 SN - 2169-9003 VL - 118 IS - 2 SP - 814 EP - 831 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Neill, Christopher A1 - Coe, Michael T. A1 - Riskin, Shelby H. A1 - Krusche, Alex V. A1 - Elsenbeer, Helmut A1 - Macedo, Marcia N. A1 - McHorney, Richard A1 - Lefebvre, Paul A1 - Davidson, Eric A. A1 - Scheffler, Raphael A1 - Figueira, Adelaine Michela e Silva A1 - Porder, Stephen A1 - Deegan, Linda A. T1 - Watershed responses to Amazon soya bean cropland expansion and intensification JF - Philosophical transactions of the Royal Society of London : B, Biological sciences N2 - The expansion and intensification of soya bean agriculture in southeastern Amazonia can alter watershed hydrology and biogeochemistry by changing the land cover, water balance and nutrient inputs. Several new insights on the responses of watershed hydrology and biogeochemistry to deforestation in Mato Grosso have emerged from recent intensive field campaigns in this region. Because of reduced evapotranspiration, total water export increases threefold to fourfold in soya bean watersheds compared with forest. However, the deep and highly permeable soils on the broad plateaus on which much of the soya bean cultivation has expanded buffer small soya bean watersheds against increased stormflows. Concentrations of nitrate and phosphate do not differ between forest or soya bean watersheds because fixation of phosphorus fertilizer by iron and aluminium oxides and anion exchange of nitrate in deep soils restrict nutrient movement. Despite resistance to biogeochemical change, streams in soya bean watersheds have higher temperatures caused by impoundments and reduction of bordering riparian forest. In larger rivers, increased water flow, current velocities and sediment flux following deforestation can reshape stream morphology, suggesting that cumulative impacts of deforestation in small watersheds will occur at larger scales. KW - soya beans KW - watersheds KW - nitrogen KW - phosphorus KW - soil Y1 - 2013 U6 - https://doi.org/10.1098/rstb.2012.0425 SN - 0962-8436 SN - 1471-2970 VL - 368 IS - 1619 PB - Royal Society CY - London ER - TY - JOUR A1 - Jolivet, Laurent A1 - Faccenna, Claudio A1 - Huet, Benjamin A1 - Labrousse, Loic A1 - Le Pourhiet, Laetitia A1 - Lacombe, Olivier A1 - Lecomte, Emmanuel A1 - Burov, Evguenii A1 - Denele, Yoann A1 - Brun, Jean-Pierre A1 - Philippon, Melody A1 - Paul, Anne A1 - Salaue, Gwenaelle A1 - Karabulut, Hayrullah A1 - Piromallo, Claudia A1 - Monie, Patrick A1 - Gueydan, Frederic A1 - Okay, Aral I. A1 - Oberhänsli, Roland A1 - Pourteau, Amaury A1 - Augier, Romain A1 - Gadenne, Leslie A1 - Driussi, Olivier T1 - Aegean tectonics strain localisation, slab tearing and trench retreat JF - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth N2 - We review the geodynamic evolution of the Aegean-Anatolia region and discuss strain localisation there over geological times. From Late Eocene to Present, crustal deformation in the Aegean backarc has localised progressively during slab retreat. Extension started with the formation of the Rhodope Metamorphic Core Complex (Eocene) and migrated to the Cyclades and the northern Menderes Massif (Oligocene and Miocene), accommodated by crustal-scale detachments and a first series of core complexes (MCCs). Extension then localised in Western Turkey, the Corinth Rift and the external Hellenic arc after Messinian times, while the North Anatolian Fault penetrated the Aegean Sea. Through time the direction and style of extension have not changed significantly except in terms of localisation. The contributions of progressive slab retreat and tearing, basal drag, extrusion tectonics and tectonic inheritance are discussed and we favour a model (I) where slab retreat is the main driving engine, (2) successive slab tearing episodes are the main causes of this stepwise strain localisation and (3) the inherited heterogeneity of the crust is a major factor for localising detachments. The continental crust has an inherited strong heterogeneity and crustal-scale contacts such as major thrust planes act as weak zones or as zones of contrast of resistance and viscosity that can localise later deformation. The dynamics of slabs at depth and the asthenospheric flow due to slab retreat also have influence strain localisation in the upper plate. Successive slab ruptures from the Middle Miocene to the late Miocene have isolated a narrow strip of lithosphere, still attached to the African lithosphere below Crete. The formation of the North Anatolian Fault is partly a consequence of this evolution. The extrusion of Anatolia and the Aegean extension are partly driven from below (asthenospheric flow) and from above (extrusion of a lid of rigid crust). KW - Backarc extension KW - Slab retreat KW - Asthenospheric flow KW - Strain localisation KW - Aegean Sea KW - Metamorphic core complex Y1 - 2013 U6 - https://doi.org/10.1016/j.tecto.2012.06.011 SN - 0040-1951 VL - 597 SP - 1 EP - 33 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Yair, Aaron A1 - Bryan, Rorke B. A1 - Lavee, Hanoch A1 - Schwanghart, Wolfgang A1 - Kuhn, Nikolaus J. T1 - The resilience of a badland area to climate change in an arid environment JF - Catena : an interdisciplinary journal of soil science, hydrology, geomorphology focusing on geoecology and landscape evolution N2 - Badlands have long been considered as model landscapes due to their perceived close relationship between form and process. The often intense features of erosion have also attracted many geomorphologists because the associated high rates of erosion appeared to offer the opportunity for studying surface processes and the resulting forms. Recently, the perceived simplicity of badlands has been questioned because the expected relationships between driving forces for erosion and the resulting sediment yield could not be observed. Further, a high variability in erosion and sediment yield has been observed across scales. Finally, denudation based on currently observed erosion rates would have lead to the destruction of most badlands a long time ago. While the perceived simplicity of badlands has sparked a disproportional (compared to the land surface they cover) amount of research, our increasing amount of information has not necessarily increased our understanding of badlands in equal terms. Overall, badlands appear to be more complex than initially assumed. In this paper, we review 40 years of research in the Zin Valley Badlands in Israel to reconcile some of the conflicting results observed there and develop a perspective on the function of badlands as model landscapes. While the data collected in the Zin Valley clearly confirm that spatial and temporal patterns of geomorphic processes and their interaction with topography and surface properties have to be understood, we still conclude that the process of realizing complexity in the "simple" badlands has a model function both for our understanding as well as perspective on all landscape systems. KW - Badlands KW - Model landscape KW - Climate change KW - Resilience Y1 - 2013 U6 - https://doi.org/10.1016/j.catena.2012.04.006 SN - 0341-8162 VL - 106 IS - 4 SP - 12 EP - 21 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Donner, Stefanie A1 - Rößler, Dirk A1 - Krüger, Frank A1 - Ghods, Abdolreza A1 - Strecker, Manfred T1 - Segmented seismicity of the M (w) 6.2 Baladeh earthquake sequence (Alborz Mountains, Iran) revealed from regional moment tensors JF - Journal of seismology N2 - The M (w) 6.2 Baladeh earthquake occurred on 28 May 2004 in the Alborz Mountains, northern Iran. This earthquake was the first strong shock in this intracontinental orogen for which digital regional broadband data are available. The Baladeh event provides a rare opportunity to study fault geometry and ongoing deformation processes using modern seismological methods. A joint inversion for hypocentres and a velocity model plus a surface-wave group dispersion curve analysis were used to obtain an adapted velocity model, customised for mid- and long-period waveform modelling. Based on the new velocity model, regional waveform data of the mainshock and larger aftershocks (M (w) a parts per thousand yen3.3) were inverted for moment tensors. For the Baladeh mainshock, this included inversion for kinematic parameters. All analysed earthquakes show dominant thrust mechanisms at depths between 14 and 26 km, with NW-SE striking fault planes. The mainshock ruptured a 28A degrees south-dipping area of 24 x 21 km along a north-easterly direction. The rupture plane of the mainshock does not coincide with the aftershock distribution, neither in map view nor with respect to depth. The considered aftershocks form two main clusters. The eastern cluster is associated with the mainshock. The western cluster does not appear to be connected with the rupture plane of the mainshock but, instead, indicates a second activated fault plane dipping at 85A degrees towards the north. KW - Alborz Mountains KW - Iran KW - Baladeh earthquake KW - Inversion for moment tensors KW - Seismotectonics Y1 - 2013 U6 - https://doi.org/10.1007/s10950-013-9362-7 SN - 1383-4649 VL - 17 IS - 3 SP - 925 EP - 959 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Scott, James M. A1 - Konrad-Schmolke, Matthias A1 - O'Brien, Patrick J. A1 - Günter, Christina T1 - High-T, low-P formation of rare olivine-bearing symplectites in variscan eclogite JF - Journal of petrology N2 - Extremely rare veinlets and reaction textures composed of symplectites of olivine (similar to Fo(43-55)) + plagioclase +/- spinel +/- ilmenite, associated with more common pyroxene + plagioclase and amphibole + plagioclase varieties, are preserved within eclogites and garnet pyroxenites in the Moldanubian Zone of the Bohemian Massif. Thermodynamic modelling integrated with conventional geothermometry conducted on an eclogite reveals that the symplectite-forming stage occurred at high T (similar to 850 degrees C) and low P (< 6 and > 2 center dot 5 kbar). The development of the different symplectite types reflects reactions that took place in micro-scale domains. The breakdown of high-P garnet controlled the formation of olivine-bearing and amphibole + plagioclase symplectites, whereas breakdown of high-P omphacite led to formation of pyroxene + plagioclase symplectites. In addition, post-eclogite facies but pre-symplectite stage porphyroblastic amphibole and phlogopite were also replaced by olivine-bearing symplectites. Material transfer calculations and thermodynamic modelling indicate that the formation of different symplectite types was linked despite their different bulk compositions. For example, the olivine-bearing symplectites gained Fe +/- Mg, whereas adjacent amphibole + plagioclase and pyroxene + plagioclase symplectites show losses in Fe and Mg; Al, Si and Ca were also variably exchanged. The olivine-bearing symplectites were particularly sensitive to Na despite the small concentration of this element. In eclogites where Na was readily available, the plagioclase composition in the olivine-bearing symplectites shifted from pure anorthite to bytownite, with the less calcic feldspar partitioning Si and inhibiting the formation of orthopyroxene. This regional high-T, low-P granulite-facies symplectite overprint may have been caused by advective heat loss from rapidly exhumed high-T, high-P granulitic bodies (Gfohl Unit) that were emplaced into and over the middle crust (Monotonous and Varied Series) during Carboniferous continent-continent collision. KW - olivine KW - symplectite KW - eclogite KW - thermodynamics KW - Variscan Y1 - 2013 U6 - https://doi.org/10.1093/petrology/egt015 SN - 0022-3530 SN - 1460-2415 VL - 54 IS - 7 SP - 1375 EP - 1398 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Tu, Rui A1 - Ge, Maorong A1 - Zhang, Hongping A1 - Huang, Guanwen T1 - The realization and convergence analysis of combined PPP based on raw observation JF - Advances in space research N2 - In order to speed up Precise Point Positioning (PPP)'s convergence, a combined PPP method with GPS and GLONASS which is based on using raw observations is proposed, and the positioning results and convergence time have been compared with that of single system. The ionospheric delays and receiver's Differential Code Bias (DCB) corrections are estimated as unknown parameters in this method. The numerical results show that the combined PPP has not caused significant impacts on the final solutions, but it greatly improved Position Dilution of Precision (PDOP) and convergence speed and enhanced the reliability of the solution. Meanwhile, the convergence speed is greatly influenced by the receiver's DCB, positioning results in horizontal which are better than 10 cm can be realized within 10 min. In addition, the ionosphere and DCB products can be provided with high precision. KW - GPS and GLONASS KW - Precise Point Positioning KW - Raw observation KW - DCB KW - Combine Y1 - 2013 U6 - https://doi.org/10.1016/j.asr.2013.03.005 SN - 0273-1177 VL - 52 IS - 1 SP - 211 EP - 221 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Grigoli, Francesco A1 - Cesca, Simone A1 - Vassallo, Maurizio A1 - Dahm, Torsten T1 - Automated seismic event location by travel-time stacking an application to mining induced seismicity JF - Seismological research letters Y1 - 2013 U6 - https://doi.org/10.1785/0220120191 SN - 0895-0695 VL - 84 IS - 4 SP - 666 EP - 677 PB - Seismological Society of America CY - Albany ER - TY - JOUR A1 - Omrani, Hadi A1 - Moazzen, Mohssen A1 - Oberhänsli, Roland A1 - Altenberger, Uwe A1 - Lange, Manuela T1 - The Sabzevar blueschists of the North-Central Iranian micro-continent as remnants of the Neotethys-related oceanic crust subduction JF - International journal of earth sciences N2 - The Sabzevar ophiolites mark the Neotethys suture in east-north-central Iran. The Sabzevar metamorphic rocks, as part of the Cretaceous Sabzevar ophiolitic complex, consist of blueschist, amphibolite and greenschist. The Sabzevar blueschists contain sodic amphibole, epidote, phengite, calcite +/- A omphacite +/- A quartz. The epidote amphibolite is composed of sodic-calcic amphibole, epidote, albite, phengite, quartz +/- A omphacite, ilmenite and titanite. The greenschist contains chlorite, plagioclase and pyrite, as main minerals. Thermobarometry of a blueschist yields a pressure of 13-15.5 kbar at temperatures of 420-500 A degrees C. Peak metamorphic temperature/depth ratios were low (similar to 12 A degrees C/km), consistent with metamorphism in a subduction zone. The presence of epidote in the blueschist shows that the rocks were metamorphosed entirely within the epidote stability field. Amphibole schist samples experienced pressures of 5-7 kbar and temperatures between 450 and 550 A degrees C. The presence of chlorite, actinolite, biotite and titanite indicate greenschist facies metamorphism. Chlorite, albite and biotite replacing garnet or glaucophane suggests temperatures of > 300 A degrees C for greenschist facies. The formation of high-pressure metamorphic rocks is related to north-east-dipping subduction of the Neotethys oceanic crust and subsequent closure during lower Eocene between the Central Iranian Micro-continent and Eurasia (North Iran). KW - Central Iranian micro-continent (CIM) KW - Neotethys Ocean KW - Glaucophane schist KW - Sabzevar KW - Iran Y1 - 2013 U6 - https://doi.org/10.1007/s00531-013-0881-9 SN - 1437-3254 VL - 102 IS - 5 SP - 1491 EP - 1512 PB - Springer CY - New York ER - TY - JOUR A1 - Mohsen, Ayman A1 - Asch, Günter A1 - Kind, Rainer A1 - Mechie, James A1 - Weber, Michael H. T1 - The lithosphere-asthenosphere boundary in the eastern part of the Dead Sea Basin (DSB) from S-to-P receiver functions JF - Arabian journal of geosciences N2 - Clear S-to-P converted waves from the crust-mantle boundary (Moho) and lithosphere-asthenosphere boundary (LAB) have been observed on the eastern part of the Dead Sea Basin (DSB), and are used for the determination of the depth of the Moho and the LAB. A temporary network consisting of 18 seismic broad-band stations was operated in the DSB region as part of the DEad Sea Integrated REsearch project for 1.5 years beginning in September 2006. The obtained Moho depth (similar to 35 km) from S-to-P receiver functions agrees well with the results from P-to-S receiver functions and other geophysical data. The thickness of the lithosphere on the eastern part of the DSB is about 75 km. The results obtained here support and confirm previous studies, based on xenolith data, geodynamic modeling, heat flow observations, and S-to-P receiver functions. Therefore, the lithosphere on the eastern part of the DSB and along Wadi Araba has been thinned in the Late Cenozoic, following rifting and spreading of the Red Sea. The thinning of the lithosphere occurred without a concomitant change in the crustal thickness and thus an upwelling of the asthenosphere in the study area is invoked as the cause of the lithosphere thinning. KW - Dead Sea basin KW - S receiver functions KW - Lithosphere Y1 - 2013 U6 - https://doi.org/10.1007/s12517-011-0503-4 SN - 1866-7511 SN - 1866-7538 VL - 6 IS - 7 SP - 2343 EP - 2350 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Hachmöller, Barbara A1 - Paasche, Hendrik T1 - Integration of surface-based tomographic models for zonation and multimodel guided extrapolation of sparsely known petrophysical parameters JF - Geophysics N2 - We integrate the information of multiple tomographic models acquired from the earth's surface by modifying a statistical approach recently developed for the integration of cross-borehole tomographic models. In doing so, we introduce spectral cluster analysis as the new core of the model integration procedure to capture the spatial heterogeneity present in all considered tomographic models and describe this heterogeneity in a fuzzy sense. Because spectral cluster algorithms analyze model structure locally, they are considered relatively robust with regard to systematically and spatially varying imaging capabilities typical for geophysical tomographic surveys conducted on the earth's surface. Using a synthetic aquifer example, a fuzzy spectral cluster algorithm can be used to integrate the information provided by 2D tomographic refraction seismic and DC resistivity surveys. The integrated information in the fuzzy membership domain is then used to derive an integrated zonal geophysical model outlining the major structural units present in both input models. We also explain how the fuzzy membership information can be used to identify optimal locations for sparse logging of additional target parameters, i.e., porosity information in our synthetic example. We demonstrate how this sparse porosity information can be extrapolated based on all tomographic input models. The resultant 2D porosity model matches the original porosity distribution reasonably well within the spatial resolution limits of the underlying tomographic models. Consecutively, we apply this approach to a field data base acquired over a former river channel. Sparse information about natural gamma radiation is available and extrapolated on the basis of the fuzzy membership information obtained by spectral cluster analysis of 2D P-wave velocity and electrical resistivity models. This field data shows that the presented parameter extrapolation procedure is robust, even if the locations of target parameter acquisition have not been optimized with regard to the fuzzy membership information. Y1 - 2013 U6 - https://doi.org/10.1190/GEO2012-0417.1 SN - 0016-8033 VL - 78 IS - 4 SP - EN43 EP - EN53 PB - Society of Exploration Geophysicists CY - Tulsa ER - TY - JOUR A1 - Cao, Xianyong A1 - Ni, Jian A1 - Herzschuh, Ulrike A1 - Wang, Yongbo A1 - Zhao, Yan T1 - A late quaternary pollen dataset from eastern continental Asia for vegetation and climate reconstructions set up and evaluation JF - Review of palaeobotany and palynology : an international journal N2 - A total of 271 pollen records were selected from a large collection of both raw and digitized pollen spectra from eastern continental Asia (70 degrees-135 degrees E and 18 degrees-55 degrees N). Following pollen percentage recalculations, taxonomic homogenization, and age-depth model revision, the pollen spectra were interpolated at a 500-year resolution and a taxonomically harmonized and temporally standardized fossil pollen dataset established with 226 pollen taxa, covering the last 22 cal lea. Of the 271 pollen records, 85% were published since 1990, with reliable chronologies and high temporal resolutions; of these, 50% have raw data with complete pollen assemblages, ensuring the quality of this dataset The pollen records available for each 500-year time slice are well distributed over all main vegetation types and climatic zones of the study area, making their pollen spectra suitable for paleovegetation and paleoclimate research. Such a dataset can be used as an example for the development of similar datasets for other regions of the world. KW - fossil pollen KW - eastern asia KW - pollen taxa KW - age-depth model KW - resampling Y1 - 2013 U6 - https://doi.org/10.1016/j.revpalbo.2013.02.003 SN - 0034-6667 VL - 194 IS - 13 SP - 21 EP - 37 PB - Elsevier CY - Amsterdam ER - TY - GEN A1 - Thiede, Rasmus Christoph A1 - Ehlers, Todd T1 - Large spatial and temporal variations in Himalayan denudation (vol 371, pg 278, 2013) T2 - Earth & planetary science letters Y1 - 2013 U6 - https://doi.org/10.1016/j.epsl.2013.07.004 SN - 0012-821X VL - 374 IS - 13 SP - 256 EP - 257 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rohrmann, Alexander A1 - Heermance, Richard A1 - Kapp, Paul A1 - Cai, Fulong T1 - Wind as the primary driver of erosion in the Qaidam Basin, China JF - Earth & planetary science letters N2 - Deserts are a major source of loess and may undergo substantial wind-erosion as evidenced by yardang fields, deflation pans, and wind-scoured bedrock landscapes. However, there are few quantitative estimates of bedrock removal by wind abrasion and deflation. Here, we report wind-erosion rates in the western Qaidam Basin in central China based on measurements of cosmogenic Be-10 in exhumed Miocene sedimentary bedrock. Sedimentary bedrock erosion rates range from 0.05 to 0.4 mm/yr, although the majority of measurements cluster at 0.125 +/- 0.05 mm/yr. These results, combined with previous work, indicate that strong winds, hyper-aridity, exposure of friable Neogene strata, and ongoing rock deformation and uplift in the western Qaidam Basin have created an environment where wind, instead of water, is the dominant agent of erosion and sediment transport. Its geographic location (upwind) combined with volumetric estimates suggest that the Qaidam Basin is a major source (up to 50%) of dust to the Chinese Loess Plateau to the east. The cosmogenically derived wind erosion rates are within the range of erosion rates determined from glacial and fluvial dominated landscapes worldwide, exemplifying the effectiveness of wind to erode and transport significant quantities of bedrock. KW - wind KW - cosmogenic nuclide-dating KW - earth surface processes KW - Chinese Loess Plateau KW - climate KW - Asia Y1 - 2013 U6 - https://doi.org/10.1016/j.epsl.2013.03.011 SN - 0012-821X VL - 374 SP - 1 EP - 10 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Glombitza, Clemens A1 - Stockhecke, Mona A1 - Schubert, Carsten J. A1 - Vetter, Alexandra A1 - Kallmeyer, Jens T1 - Sulfate reduction controlled by organic matter availability in deep sediment cores from the saline, alkaline Lake Van (Eastern Anatolia,Turkey) JF - Frontiers in microbiology N2 - As part of the International Continental Drilling Program deep lake drilling project Paleo Van, we investigated sulfate reduction (SR) in deep sediment cores of the saline, alkaline (salinity 21.4%0, alkalinity 155 m mEq-1, pH 9.81) Lake Van, Turkey. The cores were retrieved in the Northern Basin (NB) and at Ahlat Ridge (AR) and reached a maximum depth of 220 m. Additionally, 65-75 cm long gravity cores were taken at both sites. SR rates (SRR) were low (<22 nmol cm-3 day-1) compared to lakes with higher salinity and alkalinity, indicating that salinity and alkalinity are not limiting SR in Lake Van. Both sites differ significantly in rates and depth distribution of SR. In NB, SRR are up to 10 times higher than at AR. SR could be detected down to 19 mblf (meters below lake floor) at NB and down to 13 mblf at AR. Although SRR were lower at AR than at NB, organic matter (OM) concentrations were higher. In contrast, dissolved OM in the pore water at AR contained more macromolecular OM and less low molecular weight OM.VVe thus suggest, that OM content alone cannot be used to infer microbial activity at Lake Van but that quality of OM has an important impact as well. These differences suggest that biogeochemical processes in lacustrine sediments are reacting very sensitively to small variations in geological, physical, or chemical parameters over relatively short distances. KW - saline lake KW - alkaline lake KW - sulfate reduction KW - deep biosphere KW - organic matter Y1 - 2013 U6 - https://doi.org/10.3389/fmicb.2013.00209 SN - 1664-302X VL - 4 IS - 28 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Pourteau, Amaury A1 - Sudo, Masafumi A1 - Candan, Osman A1 - Lanari, P. A1 - Vidal, O. A1 - Oberhänsli, Roland T1 - Neotethys closure history of Anatolia - insights from Ar-40-Ar-39 geochronology and P-T estimation in high-pressure metasedimentary rocks JF - Journal of metamorphic geology N2 - The multiple high-pressure (HP), low-temperature (LT) metamorphic units of Western and Central Anatolia offer a great opportunity to investigate the subduction-and continental accretion-related evolution of the eastern limb of the long-lived Aegean subduction system. Recent reports of the HP-LT index mineral Fe-Mg-carpholite in three metasedimentary units of the Gondwana-derived Anatolide-Tauride continental block (namely the Afyon Zone, the Oren Unit and the southern Menderes Massif) suggest a more complicated scenario than the single-continental accretion model generally put forward in previous studies. This study presents the first isotopic dates (white mica Ar-40-Ar-39 geochronology), and where possible are combined with P-T estimates (chlorite thermometry, phengite barometry, multi-equilibrium thermobarometry), on carpholite-bearing rocks from these three HP-LT metasedimentary units. It is shown that, in the Afyon Zone, carpholite-bearing assemblages were retrogressed through greenschist-facies conditions at c. 67-62 Ma. Early retrograde stages in the Oren Unit are dated to 63-59 Ma. In the Kurudere-Nebiler Unit (HP Mesozoic cover of the southern Menderes Massif), HP retrograde stages are dated to c. 45 Ma, and post-collisional cooling to c. 26 Ma. These new results support that the Oren Unit represents the westernmost continuation of the Afyon Zone, whereas the Kurudere-Nebiler Unit correlates with the Cycladic Blueschist Unit of the Aegean Domain. In Western Anatolia, three successive HP-LT metamorphic belts thus formed: the northernmost Tavsanli Zone (c. 88-82 Ma), the Oren-Afyon Zone (between 70 and 65 Ma), and the Kurudere-Nebiler Unit (c. 52-45 Ma). The southward younging trend of the HP-LT metamorphism from the upper and internal to the deeper and more external structural units, as in the Aegean Domain, points to the persistence of subduction in Western Anatolia between 93-90 and c. 35 Ma. After the accretion of the Menderes-Tauride terrane, in Eocene times, subduction stopped, leading to continental collision and associated Barrovian-type metamorphism. Because, by contrast, the Aegean subduction did remain active due to slab roll-back and trench migration, the eastern limb (below Southwestern Anatolia) of the Hellenic slab was dramatically curved and consequently teared. It therefore is suggested that the possibility for subduction to continue after the accretion of buoyant (e.g. continental) terranes probably depends much on palaeogeography. KW - Ar-40-Ar-39 geochronology KW - Anatolia KW - chlorite-phengite thermobarometry KW - high-pressure metasedimentary rocks Y1 - 2013 U6 - https://doi.org/10.1111/jmg.12034 SN - 0263-4929 SN - 1525-1314 VL - 31 IS - 6 SP - 585 EP - 606 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Regalla, Christine A1 - Kirby, Eric A1 - Fisher, Donald A1 - Bierman, Paul R. T1 - Active forearc shortening in Tohoku, Japan - constraints on fault geometry from erosion rates and fluvial longitudinal profiles JF - Geomorphology : an international journal on pure and applied geomorphology N2 - Convexities in the longitudinal profiles of actively incising rivers are typically considered to represent the morphologic signal of a transient response to external perturbations in tectonic or climatic forcing. Distinguishing such knickzones from those that may be anchored to the channel network by spatial variations in rock uplift, however, can be challenging. Here, we combine stream profile analysis, Be-10 watershed-averaged erosion rates, and numerical modeling of stream profile evolution to evaluate whether knickzones in the Abukuma massif of northeast Japan represent a temporal or spatial change in rock uplift rate in relation to forearc shortening. Knickzones in channels that drain the eastern flank of the Abukuma massif are characterized by breaks in slope-area scaling and separate low-gradient, alluvial upper-channel segments from high-gradient, deeply-incised lower channel segments. Average erosion rates inferred from Be-10 concentrations in modern sediment below knickzones exceed erosion rates above knickzones by 20-50%. Although profile convexities could be interpreted as a transient response to an increase in rock uplift rate associated with slip on the range-bounding fault, geologic constraints on the initiation of fault slip and the magnitude of displacement cannot be reconciled with a recent, spatially uniform increase in slip rate. Rather, we find that knickzone position, stream profile gradients, and basin averaged erosion rates are best explained by a relatively abrupt spatial increase in uplift rate localized above a flat-ramp transition in the fault system. These analyses highlight the importance of considering spatially non-uniform uplift in the interpretation of stream profile evolution and demonstrate that the adjustment of river profiles to fault displacement can provide constraints on fault geometry in actively eroding landscapes. (C) 2013 Elsevier B.V. All rights reserved. KW - Knickzones KW - Fluvial longitudinal profile KW - Cosmogenic Be-10 erosion rates KW - Basement-involved thrusts KW - Futaba fault KW - Fukushima Prefecture Y1 - 2013 U6 - https://doi.org/10.1016/j.geomorph.2013.04.029 SN - 0169-555X VL - 195 IS - 8 SP - 84 EP - 98 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Rudolph, Nicole A1 - Voss, Sebastian A1 - Moradi, Ahmad B. A1 - Nagl, Stefan A1 - Oswald, Sascha T1 - Spatio-temporal mapping of local soil pH changes induced by roots of lupin and soft-rush JF - Plant and soil N2 - The rhizosphere is a dynamic system strongly influenced by root activity. Roots modify the pH of their surrounding soil causing the soil pH to vary as a function of distance from root surface, location along root axes, and root maturity. Non-invasive imaging techniques provide the possibility to capture pH patterns around the roots as they develop. We developed a novel fluorescence imaging set up and applied to the root system of two lupin (Lupinus albus L., Lupinus angustifolius L.) and one soft-rush (Juncus effusus L.) species. We grew plants in glass containers filled with soil and equipped with fluorescence sensor foils on the container side walls. We gained highly-resolved data on the spatial distribution of H+ around the roots by taking time-lapse images of the samples over the course of several days. We showed how the soil pH in the vicinity of roots developed over time to different values from that of the original bulk soil. The soil pH in the immediate vicinity of the root surface varied greatly along the root length, with the most acidic point being at 0.56-3.36 mm behind the root tip. Indications were also found for temporal soil pH changes due to root maturity. In conclusion, this study shows that this novel optical fluorescence imaging set up is a powerful tool for studying pH developments around roots in situ. KW - Acidification KW - Alkalization KW - Exudates KW - Fluorescence imaging KW - Optical sensors KW - pH mapping KW - Rhizosphere Y1 - 2013 U6 - https://doi.org/10.1007/s11104-013-1775-0 SN - 0032-079X VL - 369 IS - 1-2 SP - 669 EP - 680 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Tian, Fang A1 - Herzschuh, Ulrike A1 - Dallmeyer, Anne A1 - Xu, Qinghai A1 - Mischke, Steffen A1 - Biskaborn, Boris T1 - Environmental variability in the monsoon-westerlies transition zone during the last 1200 years - lake sediment analyses from central Mongolia and supra-regional synthesis JF - Quaternary science reviews : the international multidisciplinary research and review journal N2 - A high resolution multi proxy (pollen, grain size, total organic carbon) record from a small mountain lake (Lake Khuisiin; 46.6 degrees N, 101.8 degrees E; 2270 m a.s.l.) in the south eastern Khangai Mountains of central Mongolia has been used to explore changes in vegetation and climate over the last 1200 years. The pollen data indicates that the vegetation changed from dry steppe dominated by Poaceae and Artemisia (ca AD 760-950), to Larix forest steppe (ca AD 950-1170), Larix Betula forest steppe (ca AD 1170-1380), meadow dominated by Cyperaceae and Poaceae (ca AD 1380-1830), and Larix Betula forest steppe (after similar to AD 1830). The cold-wet period between AD 1380 and 1830 may relate to the Little Ice Age. Environmental changes were generally subtle and climate change seems to have been the major driver of variations in vegetation until at least the early part of the 20th century, suggesting that either the level of human activity was generally low, or the relationship between human activity and vegetation did not alter substantially between AD 760 and 1830. A review of centennial scale moisture records from China and Mongolia revealed that most areas experienced major changes at ca AD 1500 and AD 1900. However, the moisture availability since AD 1500 varied between sites, with no clear regional pattern or relationship to present day conditions. Both the reconstructions and the moisture levels simulation on a millennium scale performed in the MPI Earth System Model indicate that the monsoon-westerlies transition area shows a greater climate variability than those areas influenced by the westerlies, or by the summer monsoon only. KW - Pollen KW - Grain size KW - TOC KW - Asian monsoon KW - Westerlies KW - Late Holocene KW - Vegetation change KW - Mongolia Y1 - 2013 U6 - https://doi.org/10.1016/j.quascirev.2013.05.005 SN - 0277-3791 VL - 73 IS - 2 SP - 31 EP - 47 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Meere, Patrick A. A1 - Mulchrone, Kieran F. A1 - Timmerman, Martin T1 - Shear folding in low-grade metasedimentary rocks - reverse shear along cleavage at a high angle to the maximum compressive stress JF - Geology N2 - Shear folding, which is also referred to as slip folding, involves shear along planes that are oriented approximately parallel to the axial plane of the fold structure. These planes, which are typically axial-planar cleavage planes, facilitate high-angle reverse slip leading to fold limb rotation and amplification. This study builds on recent advances in our understanding of the role of weak fault zones in facilitating slip on misoriented faults; i.e., faults at a high angle to the maximum principal tectonic stress (sigma(1)). Analysis of folded marine sedimentary rocks from the Variscan of southern Ireland provides unambiguous microstructural evidence for reverse shear on chemically weakened cleavage domains. Significant silica loss in these cleavage domains, and as a consequence marked mechanical weakening, is seen as the primary cause for the reverse slip associated with the shear folding of these sedimentary rocks. Y1 - 2013 U6 - https://doi.org/10.1130/G34150.1 SN - 0091-7613 VL - 41 IS - 8 SP - 879 EP - 882 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Schertl, Hans-Peter A1 - O'Brien, Patrick T1 - Continental crust at mantle depths - key minerals and microstructures JF - Elements : an international magazine of mineralogy, geochemistry, and petrology N2 - Finding evidence for ultrahigh-pressure (UHP) metamorphism in crustal rocks is far from straightforward. The index minerals coesite and diamond are incredibly inconspicuous and are therefore difficult to use as UHP prospecting tools. Consequently, petrographers rely on recognizing subtle breakdown microstructures that result from pressure release during the return to the surface of the once deeply buried rock. Similarly, many other UHP minerals are first suspected on the basis of typical reaction or exsolution microstructures. Thus, the painstaking use of microscopic techniques has been fundamental to the tremendous advances in characterizing, quantifying, and understanding macroscopic-scale, deep continental subduction, rapid exhumation, and mountain-building processes. KW - ultrahigh-pressure KW - coesite KW - microdiamond KW - majorite KW - exsolution microstructures KW - polymorphism Y1 - 2013 U6 - https://doi.org/10.2113/gselements.9.4.261 SN - 1811-5209 SN - 1811-5217 VL - 9 IS - 4 SP - 261 EP - 266 PB - Mineralogical Society of America CY - Chantilly ER - TY - JOUR A1 - Kaiser, Björn Onno A1 - Cacace, Mauro A1 - Scheck-Wenderoth, Magdalena T1 - Quaternary channels within the Northeast German Basin and their relevance on double diffusive convective transport processes - constraints from 3-D thermohaline numerical simulations JF - Geochemistry, geophysics, geosystems N2 - The internal geological structure of the Northeast German Basin (NEGB) is affected by intense salt diapirism and by the presence of several stratified aquifer complexes of regional relevance. The shallow Quaternary to late Tertiary freshwater aquifer is separated from the underlying Mesozoic saline aquifers by an embedded Tertiary clay enriched aquitard (Rupelian Aquitard). An important feature of this aquitard is that hydraulic connections between the upper and lower aquifers do exist in areas where the Rupelian Aquitard is missing (hydrogeological windows). Three-dimensional thermohaline numerical simulations are carried out to investigate the effects of such hydrogeological windows in the Rupelian Aquitard on the resulting groundwater, temperature, and salinity distributions. Numerical results suggest that hydrogeological windows act as preferential domains of hydraulic interconnectivity between the different aquifers at depth and enable vigorous heat and mass transport which causes a mixing of warm and saline groundwater with cold and less saline groundwater within both aquifers. In areas where the Rupelian Aquitard confines the Mesozoic aquifer, dissolved solutes from major salt structures are transported laterally giving rise to plumes of variable salinity content ranging from few hundreds of meters to several tens of kilometers. Furthermore, destabilizing thermal buoyancy forces may overwhelm counteracting stabilizing salinity induced forces offside of salt domes. This may result in buoyant upward groundwater flow transporting heat and mass to shallower levels within the same Mesozoic Aquifer. KW - double diffusive convection KW - thermohaline processes KW - numerical simulations KW - salt structures KW - Northeast German Basin KW - quarternary channels Y1 - 2013 U6 - https://doi.org/10.1002/ggge.20192 SN - 1525-2027 VL - 14 IS - 8 SP - 3156 EP - 3175 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Gocke, Martina A1 - Liang, Wu A1 - Sommer, Michael A1 - Kuzyakov, Yakov T1 - Silicon uptake by wheat - effects of Si pools and pH JF - Journal of plant nutrition and soil science = Zeitschrift für Pflanzenernährung und Bodenkunde N2 - Silicon (Si), although not considered essential, has beneficial effects on plant growth which are mostly associated with the ability to accumulate amorphous (phytogenic) Si, e.g., as phytoliths. Phytogenic Si is the most active Si pool in the soil-plant system because of its great surface-to-volume ratio, amorphous structure, and high water solubility. Despite the high abundance of Si in terrestrial biogeosystems and its importance, e.g., for the global C cycle, little is known about Si fluxes between soil and plants and Si pools used by plants. This study aims at elucidating the contribution of various soil Si pools to Si uptake by wheat. As pH affects dissolution of Si pools and Si uptake by plants, the effect of pH (4.5 and 7) was evaluated. Wheat was grown on Si-free pellets mixed with one of the following Si pools: quartz sand (crystalline), anorthite powder (crystalline), or silica gel (amorphous). Silicon content was measured in aboveground biomass, roots, and soil solution 4 times in intervals of 7 d. At pH 4.5, plants grew best on anorthite, but pH did not significantly affect Si-uptake rates. Total Si contents in plant biomass were significantly higher in the silica-gel treatment compared to all other treatments, with up to 26 mg g(-1) in aboveground biomass and up to 17 mg g(-1) in roots. Thus, Si uptake depends on the conversion of Si into plant-available silicic acid. This conversion occurs too slowly for crystalline Si phases, therefore Si uptake from treatments with quartz sand and anorthite did not differ from the control. For plants grown on silica gel, real Si-uptake rates were higher than the theoretical value calculated based on water transpiration. This implies that Si uptake by wheat is driven not only by passive water flux but also by active transporters, depending on Si concentration in the aqueous phase, thus on type of Si pool. These results show that Si uptake by plants as well as plant growth are significantly affected by the type of Si pool and factors controlling its solubility. KW - anorthite KW - global Si cycle KW - phytogenic silica KW - quartz KW - silica gel KW - soil Si pools KW - Triticum aestivum L Y1 - 2013 U6 - https://doi.org/10.1002/jpln.201200098 SN - 1436-8730 SN - 1522-2624 VL - 176 IS - 4 SP - 551 EP - 560 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Reichstein, Markus A1 - Bahn, Michael A1 - Ciais, Philippe A1 - Frank, Dorothea A1 - Mahecha, Miguel D. A1 - Seneviratne, Sonia I. A1 - Zscheischler, Jakob A1 - Beer, Christian A1 - Buchmann, Nina A1 - Frank, David C. A1 - Papale, Dario A1 - Rammig, Anja A1 - Smith, Pete A1 - Thonicke, Kirsten A1 - van der Velde, Marijn A1 - Vicca, Sara A1 - Walz, Ariane A1 - Wattenbach, Martin T1 - Climate extremes and the carbon cycle JF - Nature : the international weekly journal of science N2 - The terrestrial biosphere is a key component of the global carbon cycle and its carbon balance is strongly influenced by climate. Continuing environmental changes are thought to increase global terrestrial carbon uptake. But evidence is mounting that climate extremes such as droughts or storms can lead to a decrease in regional ecosystem carbon stocks and therefore have the potential to negate an expected increase in terrestrial carbon uptake. Here we explore the mechanisms and impacts of climate extremes on the terrestrial carbon cycle, and propose a pathway to improve our understanding of present and future impacts of climate extremes on the terrestrial carbon budget. Y1 - 2013 U6 - https://doi.org/10.1038/nature12350 SN - 0028-0836 VL - 500 IS - 7462 SP - 287 EP - 295 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Wiesmeier, Martin A1 - Hübner, Rico A1 - Barthold, Frauke Katrin A1 - Spörlein, Peter A1 - Geuss, Uwe A1 - Hangen, Edzard A1 - Reischl, Arthur A1 - Schilling, Bernd A1 - von Lützow, Margit A1 - Kögel-Knabner, Ingrid T1 - Amount, distribution and driving factors of soil organic carbon and nitrogen in cropland and grassland soils of southeast Germany (Bavaria) JF - Agriculture, ecosystems & environment : an international journal for scientific research on the relationship of agriculture and food production to the biosphere N2 - Agricultural soils have a high potential for sequestration of atmospheric carbon due to their volume and several promising management options. However, there is a remarkable lack of information about the status quo of organic carbon in agricultural soils. In this study a comprehensive data set of 384 cropland soils and 333 grassland soils within the state of Bavaria in southeast Germany was analyzed in order to provide representative information on total amount, regional distribution and driving parameters of soil organic carbon (SOC) and nitrogen (N) in agricultural soils of central Europe. The results showed that grassland soils stored higher amounts of SOC (11.8 kg m(-2)) and N (0.92 kg m(-2)) than cropland soils (9.0 and 0.66 kg m(-2), respectively) due to moisture-induced accumulation of soil organic matter (SOM) in B horizons. Surprisingly, no distinct differences were found for the A horizons since tillage led to a relocation of SOM with depth in cropland soils. Statistical analyses of driving factors for SOM storage revealed soil moisture, represented by the topographic wetness index (TWI), as the most important parameter for both cropland and grassland soils. Climate effects (mean annual temperature and precipitation) were of minor importance in agricultural soils because management options counteracted them to a certain extent, particularly in cropland soils. The distribution of SOC and N stocks within Bavaria based on agricultural regions confirmed the importance of soil moisture since the highest cropland SOC and N stocks were found for tertiary hills and loess regions, which exhibited large areas with potentially high soil moisture content in extant floodplains. Grassland soils showed the highest accumulation of SOC and N in the Alps and Pre-Alps as a result of low temperatures, high amounts of precipitation and high soil moisture content in areas of glacial denudation. Soil class was identified as a further driving parameter for SOC and N storage in cropland soils. In total, cropland and grassland soils in Bavaria store 242 and 134 Mt SOC as well as 19 and 12 Mt N down to a soil depth of 1 m or the parent material, respectively. KW - Soil organic carbon stocks KW - Topographic Wetness Index (TWI) KW - Soil moisture KW - Carbon sequestration KW - Agricultural soils Y1 - 2013 U6 - https://doi.org/10.1016/j.agee.2013.05.012 SN - 0167-8809 VL - 176 IS - 32 SP - 39 EP - 52 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Tomas, Sara A1 - Homann, Martin A1 - Mutti, Maria A1 - Amour, Frederic A1 - Christ, Nicolas A1 - Immenhauser, Adrian A1 - Agar, Susan M. A1 - Kabiri, Lahcen T1 - Alternation of microbial mounds and ooid shoals (Middle Jurasssic, Morocco) - response to paleoenvironmental changes JF - Sedimentary geology : international journal of applied and regional sedimentology N2 - The occurrence of neritic microbial carbonates is often related to ecological refuges, where grazers and other competitors are reduced by environmental conditions, or to post-extinction events (e.g. in the Late Devonian, Early Triassic). Here, we present evidence for Middle Jurassic (Bajocian) microbial mounds formed in the normal marine, shallow neritic setting of an inner, ramp system from the High Atlas of Morocco. The microbial mounds are embedded in cross-bedded oolitic facies. Individual mounds show low relief domal geometries (up to 3 m high and 4.5 m across), but occasionally a second generation of mounds exhibits tabular geometries (<1 m high). The domes are circular in plan view and have intact tops, lacking evidence of current influence on mound preferred growth direction or distribution patterns, or truncation. The mound fades consists almost entirely of non-laminated, micritic thrombolites with branching morphologies and fine-grained, clotted and peloidal fabrics. Normal marine biota are present but infrequent. Several lines of evidence document that microbial mound growth alternates with time intervals of active ooid shoal deposition. This notion is of general significance when compared with modern Bahamian microbialites that co-exist with active sub-aquatic dunes. Furthermore, the lack of detailed studies of Middle Jurassic, normal marine shallow neritic microbial mounds adds a strong motivation for the present study. Specifically, Bajocian mounds formed on a firmground substratum during transgressive phases under condensed sedimentation. Furthermore, a transient increase in nutrient supply in the prevailing mesotrophic setting, as suggested by the heterotrophic-dominated biota, may have controlled microbial mound stages. KW - Microbial mounds KW - Thrombolites KW - Ooid shoals KW - Paleoenvironment KW - Jurassic Y1 - 2013 U6 - https://doi.org/10.1016/j.sedgeo.2013.05.008 SN - 0037-0738 VL - 294 SP - 68 EP - 82 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Hund, Silja V. A1 - Brown, Sandra A1 - Lavkulich, Les M. A1 - Oswald, Sascha T1 - Relating P Lability in Stream Sediments to Watershed Land Use via an Effective Sequential Extraction Scheme JF - Water, air & soil pollution : an international journal of environmental pollution N2 - High applications of P fertilizers and manure are general practice in intensive agriculture and may cause eutrophication in adjacent streams. Bioavailability of P can be estimated by sequential extractions commonly used for soil or sediment. A single combined method may facilitate more effective comparisons of topsoils and adjoining stream sediments, and enhance management decisions. In this study, the suitability of an established soil P sequential extraction was tested on stream bed sediments. The study was conducted in the Sumas River watershed in the agricultural Lower Fraser Valley, Canada. Sediment samples with differing land use (forest, low and high intensity agriculture) from 1993, 1994, 2008, and 2009 from 14 sites along the Sumas River and tributaries were used. Total sequential extraction concentrations were in agreement with aqua regia digestion (Rs=0.96) and showed consistency over the study time sequence. P fractions released by 0.5 M NaHCO3 (median 14 %), 0.1 M NaOH (33 %), and 1.0 M HCl (38 %) were significantly (alpha=0.05) higher than P released by other extractants. These three extraction steps provide a practical and time-effective assessment of P lability in stream sediments and may be used as a combined scheme for sediment and soil. Analytical results further revealed that land use has a major and characteristic impact on P lability. With a land use change from forest to intensive agriculture, results showed an increase in total P concentrations (30 to 4,000 ppm) and in P lability, in particular for the moderately labile NaOH-P fraction (20 to 50 %). KW - Phosphorus KW - Eutrophication KW - Availability KW - Sequential extraction KW - Agriculture KW - River bed sediment Y1 - 2013 U6 - https://doi.org/10.1007/s11270-013-1643-9 SN - 0049-6979 SN - 1573-2932 VL - 224 IS - 9 PB - Springer CY - Dordrecht ER - TY - JOUR A1 - Hoffmann, Bernd A1 - Kahmen, Ansgar A1 - Cernusak, Lucas A. A1 - Arndt, Stefan K. A1 - Sachse, Dirk T1 - Abundance and distribution of leaf wax n-alkanes in leaves of Acacia and Eucalyptus trees along a strong humidity gradient in northern Australia JF - Organic geochemistry : the international journal for rapid publication of current research in organic geochemistry and biochemistry N2 - Environmental parameters such as rainfall, temperature and relative humidity can affect the composition of higher plant leaf wax. The abundance and distribution of leaf wax biomarkers, such as long chain n-alkanes, in sedimentary archives have therefore been proposed as proxies reflecting climate change. However, a robust palaeoclimatic interpretation requires a thorough understanding of how environmental changes affect leaf wax n-alkane distributions in living plants. We have analysed the concentration and chain length distribution of leaf wax n-alkanes in Acacia and Eucalyptus species along a 1500 km climatic gradient in northern Australia that ranges from subtropical to arid. We show that aridity affected the concentration and distribution of n-alkanes for plants in both genera. For both Acacia and Eucalyptus n-alkane concentration increased by a factor of ten to the dry centre of Australia, reflecting the purpose of the wax in preventing water loss from the leaf. Furthermore, Acacian-alkanes decreased in average chain length (ACL) towards the arid centre of Australia, whereas Eucalyptus ACL increased under arid conditions. Our observations demonstrate that n-alkane concentration and distribution in leaf wax are sensitive to hydroclimatic conditions. These parameters could therefore potentially be employed in palaeorecords to estimate past environmental change. However, our finding of a distinct response of n-alkane ACL values to hydrological changes in different taxa also implies that the often assumed increase in ACL under drier conditions is not a robust feature for all plant species and genera and as such additional information about the prevalent vegetation are required when ACL values are used as a palaeoclimate proxy. Y1 - 2013 U6 - https://doi.org/10.1016/j.orggeochem.2013.07.003 SN - 0146-6380 VL - 62 IS - 9 SP - 62 EP - 67 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - König, Hannes Jochen A1 - Uthes, Sandra A1 - Schuler, Johannes A1 - Zhen, Lin A1 - Purushothaman, Seema A1 - Suarma, Utia A1 - Sghaier, Mongi A1 - Makokha, Stella A1 - Helming, Katharina A1 - Sieber, Stefan A1 - Chen, Le A1 - Brouwer, Floor A1 - Morris, Jake A1 - Wiggering, Hubert T1 - Regional impact assessment of land use scenarios in developing countries using the FoPIA approach - findings from five case studies JF - Journal of environmental management N2 - The impact of land use changes on sustainable development is of increasing interest in many regions of the world. This study aimed to test the transferability of the Framework for Participatory Impact Assessment (FoPIA), which was originally developed in the European context, to developing countries, in which lack of data often prevents the use of data-driven impact assessment methods. The core aspect of FoPIA is the stakeholder-based assessment of alternative land use scenarios. Scenario impacts on regional sustainability are assessed by using a set of nine regional land use functions (LUFs), which equally cover the economic, social and environmental dimensions of sustainability. The cases analysed in this study include (1) the alternative spatial planning policies around the Merapi volcano and surrounding areas of Yogyakarta City, Indonesia; (2) the large-scale afforestation of agricultural areas to reduce soil erosion in Guyuan, China; (3) the expansion of soil and water conservation measures in the Oum Zessar watershed, Tunisia; (4) the agricultural intensification and the potential for organic agriculture in Bijapur, India; and (5) the land degradation and land conflicts resulting from land division and privatisation in Narok, Kenya. All five regions are characterised by population growth, partially combined with considerable economic development, environmental degradation problems and social conflicts. Implications of the regional scenario impacts as well as methodological aspects are discussed. Overall, FoPIA proved to be a useful tool for diagnosing regional human-environment interactions and for supporting the communication and social learning process among different stakeholder groups. KW - (Ex-ante) impact assessment KW - Land use change KW - Scenario study KW - Sustainable development KW - Stakeholder participation KW - Developing countries KW - Indicators Y1 - 2013 U6 - https://doi.org/10.1016/j.jenvman.2012.10.021 SN - 0301-4797 SN - 1095-8630 VL - 127 SP - S56 EP - S64 PB - Elsevier CY - London ER - TY - JOUR A1 - Tekken, Vera A1 - Costa, Luís Fílípe Carvalho da A1 - Kropp, Jürgen T1 - Increasing pressure, declining water and climate change in north-eastern Morocco JF - Journal of coastal conservation : planning and management N2 - The coastal stretch of north-eastern Mediterranean Morocco holds vitally important ecological, social, and economic functions. The implementation of large-scale luxury tourism resorts shall push socio-economic development and facilitate the shift from a mainly agrarian to a service economy. Sufficient water availability and intact beaches are among the key requirements for the successful realization of regional development plans. The water situation is already critical, additional water-intense sectors could overstrain the capacity of water resources. Further, coastal erosion caused by sea-level rise is projected. Regional climate change is observable, and must be included in regional water management. Long-term climate trends are assessed for the larger region (Moulouya basin) and for the near-coastal zone at Saidia. The amount of additional water demand is assessed for the large-dimensioned Saidia resort; including the monthly, seasonal and annual tourist per capita water need under inclusion of irrigated golf courses and garden areas. A shift of climate patterns is observed, a lengthening of the dry summer season, and as well a significant decline of annual precipitation. Thus, current water scarcity is mainly human-induced; however, climate change will aggravate the situation. As a consequence, severe environmental damage due to water scarcity is likely and could impinge on the quality of local tourism. The re-adjustment of current management routines is therefore essential. Possible adjustments are discussed and the analysis concludes with management recommendations for innovative regional water management of tourism facilities. KW - North-eastern Morocco KW - Climate change KW - Coastal zone KW - Luxury tourism KW - Water demand KW - Adaptation Y1 - 2013 U6 - https://doi.org/10.1007/s11852-013-0234-7 SN - 1400-0350 VL - 17 IS - 3 SP - 379 EP - 388 PB - Springer CY - New York ER - TY - JOUR A1 - Cammerer, Holger A1 - Thieken, Annegret A1 - Verburg, Peter H. T1 - Spatio-temporal dynamics in the flood exposure due to land use changes in the Alpine Lech Valley in Tyrol (Austria) JF - Natural hazards : journal of the International Society for the Prevention and Mitigation of Natural Hazards N2 - Flood risk is expected to increase in many regions of the world in the next decades with rising flood losses as a consequence. First and foremost, it can be attributed to the expansion of settlement and industrial areas into flood plains and the resulting accumulation of assets. For a future-oriented and a more robust flood risk management, it is therefore of importance not only to estimate potential impacts of climate change on the flood hazard, but also to analyze the spatio-temporal dynamics of flood exposure due to land use changes. In this study, carried out in the Alpine Lech Valley in Tyrol (Austria), various land use scenarios until 2030 were developed by means of a spatially explicit land use model, national spatial planning scenarios and current spatial policies. The combination of the simulated land use patterns with different inundation scenarios enabled us to derive statements about possible future changes in flood-exposed built-up areas. The results indicate that the potential assets at risk depend very much on the selected socioeconomic scenario. The important conditions affecting the potential assets at risk that differ between the scenarios are the demand for new built-up areas as well as on the types of conversions allowed to provide the necessary areas at certain locations. The range of potential changes in flood-exposed residential areas varies from no further change in the most moderate scenario 'Overall Risk' to 119 % increase in the most extreme scenario 'Overall Growth' (under current spatial policy) and 159 % increase when disregarding current building restrictions. KW - Flood risk KW - Land use change KW - Spatial policy KW - Socioeconomic scenarios KW - Mountain basins Y1 - 2013 U6 - https://doi.org/10.1007/s11069-012-0280-8 SN - 0921-030X VL - 68 IS - 3 SP - 1243 EP - 1270 PB - Springer CY - New York ER - TY - JOUR A1 - Herzschuh, Ulrike A1 - Pestryakova, Luidmila Agafyevna A1 - Savelieva, Larissa A. A1 - Heinecke, Liv A1 - Böhmer, Thomas A1 - Biskaborn, Boris A1 - Andreev, Andrei A1 - Ramisch, Arne A1 - Shinneman, Avery L. C. A1 - Birks, H. John B. T1 - Siberian larch forests and the ion content of thaw lakes form a geochemically functional entity JF - Nature Communications N2 - Siberian larch forests growing on shallow permafrost soils have not, until now, been considered to be controlling the abiotic and biotic characteristics of the vast number of thaw-lake ecosystems. Here we show, using four independent data sets (a modern data set from 201 lakes from the tundra to taiga, and three lake-core records), that lake-water geochemistry in Yakutia is highly correlated with vegetation. Alkalinity increases with catchment forest density. We postulate that in this arid area, higher evapotranspiration in larch forests compared with that in the tundra vegetation leads to local salt accumulation in soils. Solutes are transported to nearby thaw lakes during rain events and snow melt, but are not fully transported into rivers, because there is no continuous groundwater flow within permafrost soils. This implies that potentially large shifts in the chemical characteristics of aquatic ecosystems to known warming are absent because of the slow response of catchment forests to climate change. Y1 - 2013 U6 - https://doi.org/10.1038/ncomms3408 SN - 2041-1723 VL - 4 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Hoffmann, Thomas A1 - Schlummer, Manuela A1 - Notebaert, Bastiaan A1 - Verstraeten, Gert A1 - Korup, Oliver T1 - Carbon burial in soil sediments from Holocene agricultural erosion, Central Europe JF - Global biogeochemical cycles N2 - Natural and human-induced erosion supplies high amounts of soil organic carbon (OC) to terrestrial drainage networks. Yet OC fluxes in rivers were considered in global budgets only recently. Modern estimates of annual carbon burial in inland river sediments of 0.6 Gt C, or 22% of C transferred from terrestrial ecosystems to river channels, consider only lakes and reservoirs and disregard any long-term carbon burial in hillslope or floodplain sediments. Here we present the first assessment of sediment-bound OC storage in Central Europe from a synthesis of similar to 1500 Holocene hillslope and floodplain sedimentary archives. We show that sediment storage increases with drainage-basin size due to more extensive floodplains in larger river basins. However, hillslopes retain hitherto unrecognized high amounts of eroded soils at the scale of large river basins such that average agricultural erosion rates during the Holocene would have been at least twice as high as reported previously. This anthropogenic hillslope sediment storage exceeds floodplain storage in drainage basins <10(5) km(2), challenging the notion that floodplains are the dominant sedimentary sinks. In terms of carbon burial, OC concentrations in floodplains exceed those on hillslopes, and net OC accumulation rates in floodplains (0.70.2 g C m(-2)a(-1)) surpass those on hillslopes (0.40.1 g C m(-2)a(-1)) over the last 7500 years. We conclude that carbon burial in floodplains and on hillslopes in Central Europe exceeds terrestrial carbon storage in lakes and reservoirs by at least 2 orders of magnitude and should thus be considered in continental carbon budgets. KW - soil organic carbon KW - human impact KW - soil erosion KW - hillslope KW - floodplain KW - deposition Y1 - 2013 U6 - https://doi.org/10.1002/gbc.20071 SN - 0886-6236 SN - 1944-9224 VL - 27 IS - 3 SP - 828 EP - 835 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Landgraf, Angela A1 - Zielke, Olaf A1 - Arrowsmith, J. Ramón A1 - Ballato, Paolo A1 - Strecker, Manfred A1 - Schildgen, Taylor F. A1 - Friedrich, Anke M. A1 - Tabatabaei, Sayyed-Hassan T1 - Differentiating simple and composite tectonic landscapes using numerical fault slip modeling with an example from the south central Alborz Mountains, Iran JF - Journal of geophysical research : Earth surface N2 - The tectonically driven growth of mountains reflects the characteristics of the underlying fault systems and the applied tectonic forces. Over time, fault networks might be relatively static, but stress conditions could change and result in variations in fault slip orientation. Such a tectonic landscape would transition from a simple to a composite state: the topography of simple landscapes is correlated with a single set of tectonic boundary conditions, while composite landscapes contain inherited topography due to earlier deformation under different boundary conditions. We use fault interaction modeling to compare vertical displacement fields with topographic metrics to differentiate the two types of landscapes. By successively rotating the axis of maximum horizontal stress, we produce a suite of vertical displacement fields for comparison with real landscapes. We apply this model to a transpressional duplex in the south central Alborz Mountains of Iran, where NW oriented compression was superseded by neotectonic NE compression. The consistency between the modeled displacement field and real landforms indicates that the duplex topography is mostly compatible with the modern boundary conditions, but might include a small remnant from the earlier deformation phase. Our approach is applicable for various tectonic settings and represents an approach to identify the changing boundary conditions that produce composite landscapes. It may be particularly useful for identifying changes that occurred in regions where river profiles may no longer record a signal of the change or where the spatial pattern of uplift is complex. KW - fault interaction KW - landscape evolution KW - numerical modeling KW - Alborz Mountains KW - Iran Y1 - 2013 U6 - https://doi.org/10.1002/jgrf.20109 SN - 2169-9003 SN - 2169-9011 VL - 118 IS - 3 SP - 1792 EP - 1805 PB - American Geophysical Union CY - Washington ER -