TY  - JOUR
A1  - Bruttel, Lisa Verena
A1  - Friehe, Tim
T1  - Can short-term incentives induce long-lasting cooperation? Results from a public-goods experiment
JF  - Journal of behavioral and experimental economics
N2  - This paper investigates whether providing strong cooperation incentives only at the outset of a group interaction spills over to later periods to ensure cooperation in the long run. We study a repeated linear public-good game with punishment opportunities and a parameter change after the first ten (of twenty) rounds. Our data shows that cooperation among subjects who had experienced a higher marginal return on public-good contributions or low punishment costs in rounds 1-10 rapidly deteriorated in rounds 11-20 once these incentives were removed, eventually trending below the level of cooperation in the control group. This suggests the possibility of temporary incentives backfiring in the long run. This paper ties in with the literature highlighting the potentially adverse effects of the use of incentives. (C) 2014 Elsevier Inc. All rights reserved.
KW  - Public good game
KW  - Team
KW  - Punishment
KW  - Incentives
KW  - Experiment
Y1  - 2014
U6  - https://doi.org/10.1016/j.socec.2014.09.001
SN  - 2214-8043
SN  - 2214-8051
VL  - 53
SP  - 120
EP  - 130
PB  - Elsevier
CY  - New York
ER  - 
TY  - THES
A1  - Maghsoudi, Samira
T1  - Spatiotemporal microseismicity patterns and detection performance in mining environments
Y1  - 2014
CY  - Potsdam
ER  - 
TY  - JOUR
A1  - Braeuer, Benjamin
A1  - Asch, Günter
A1  - Hofstetter, Rami
A1  - Haberland, Christian
A1  - Jaser, D.
A1  - El-Kelani, R.
A1  - Weber, Michael H.
T1  - Detailed seismicity analysis revealing the dynamics of the southern Dead Sea area
JF  - Journal of seismology
N2  - Within the framework of the international DESIRE (DEad Sea Integrated REsearch) project, a dense temporary local seismological network was operated in the southern Dead Sea area. During 18 recording months, 648 events were detected. Based on an already published tomography study clustering, focal mechanisms, statistics and the distribution of the microseismicity in relation to the velocity models from the tomography are analysed. The determined b value of 0.74 leads to a relatively high risk of large earthquakes compared to the moderate microseismic activity. The distribution of the seismicity indicates an asymmetric basin with a vertical strike-slip fault forming the eastern boundary of the basin, and an inclined western boundary, made up of strike-slip and normal faults. Furthermore, significant differences between the area north and south of the Bokek fault were observed. South of the Bokek fault, the western boundary is inactive while the entire seismicity occurs on the eastern boundary and below the basin-fill sediments. The largest events occurred here, and their focal mechanisms represent the northwards transform motion of the Arabian plate along the Dead Sea Transform. The vertical extension of the spatial and temporal cluster from February 2007 is interpreted as being related to the locking of the region around the Bokek fault. North of the Bokek fault similar seismic activity occurs on both boundaries most notably within the basin-fill sediments, displaying mainly small events with strike-slip mechanism and normal faulting in EW direction. Therefore, we suggest that the Bokek fault forms the border between the single transform fault and the pull-apart basin with two active border faults.
KW  - Dead Sea basin
KW  - Microseismicity
KW  - Cluster
KW  - Pull-apart basin
KW  - Asymmetric basin
KW  - Transform fault
Y1  - 2014
U6  - https://doi.org/10.1007/s10950-014-9441-4
SN  - 1383-4649
SN  - 1573-157X
VL  - 18
IS  - 4
SP  - 731
EP  - 748
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Werner, Andrea
A1  - Werner, Andreas
A1  - Wieland, Ralf
A1  - Kersebaum, Kurt-Christian
A1  - Mirschel, Wilfried
A1  - Ende, Hans-Peter
A1  - Wiggering, Hubert
T1  - Ex ante assessment of crop rotations focusing on energy crops using a multi-attribute decision-making method
JF  - Ecological indicators : integrating monitoring, assessment and management
N2  - The cultivation of plants for use as energy resources is an agricultural and industrial sector with potentially synergistic benefits related to protecting the environment and generating income. Against the background of increasing land-use changes and new agricultural approaches to the production of energy crops, we present a method for identifying future-oriented crop rotations that supports both the economic and environmental components of decision-making strategies with respect to agriculture-related policy decisions (regional mission statements). The conflicting aspects of these objectives can be addressed with the analytic hierarchy process (AHP), a multi-attribute decision-making method that was integrated here. Three models are used to generate simulations of the defined objectives over a planning period of 30 years under the current climate scenario and provide input data for the multi-attribute assessment of several crop rotations. Based on the entire evaluation process, dimensionless global priority vectors are used to indicate how well the crop rotations meet the requirements of the defined mission statement. The method is tested in a municipality in NE Germany. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Agricultural management
KW  - Ex ante assessment
KW  - Multi-attribute decision-making
KW  - AHP
KW  - Crop rotation
KW  - Energy crops
KW  - Regional objectives
KW  - Indicators
Y1  - 2014
U6  - https://doi.org/10.1016/j.ecolind.2014.03.013
SN  - 1470-160X
SN  - 1872-7034
VL  - 45
SP  - 110
EP  - 122
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Freundt, A.
A1  - Grevemeyer, I.
A1  - Rabbel, W.
A1  - Hansteen, T. H.
A1  - Hensen, C.
A1  - Wehrmann, H.
A1  - Kutterolf, S.
A1  - Halama, Ralf
A1  - Frische, M.
T1  - Volatile (H2O, CO2, Cl, S) budget of the Central American subduction zone
JF  - International journal of earth sciences
N2  - After more than a decade of multidisciplinary studies of the Central American subduction zone mainly in the framework of two large research programmes, the US MARGINS program and the German Collaborative Research Center SFB 574, we here review and interpret the data pertinent to quantify the cycling of mineral-bound volatiles (H2O, CO2, Cl, S) through this subduction system. For input-flux calculations, we divide the Middle America Trench into four segments differing in convergence rate and slab lithological profiles, use the latest evidence for mantle serpentinization of the Cocos slab approaching the trench, and for the first time explicitly include subduction erosion of forearc basement. Resulting input fluxes are 40-62 (53) Tg/Ma/m H2O, 7.8-11.4 (9.3) Tg/Ma/m CO2, 1.3-1.9 (1.6) Tg/Ma/m Cl, and 1.3-2.1 (1.6) Tg/Ma/m S (bracketed are mean values for entire trench length). Output by cold seeps on the forearc amounts to 0.625-1.25 Tg/Ma/m H2O partly derived from the slab sediments as determined by geochemical analyses of fluids and carbonates. The major volatile output occurs at the Central American volcanic arc that is divided into ten arc segments by dextral strike-slip tectonics. Based on volcanic edifice and widespread tephra volumes as well as calculated parental magma masses needed to form observed evolved compositions, we determine long-term (10(5) years) average magma and K2O fluxes for each of the ten segments as 32-242 (106) Tg/Ma/m magma and 0.28-2.91 (1.38) Tg/Ma/m K2O (bracketed are mean values for entire Central American volcanic arc length). Volatile/K2O concentration ratios derived from melt inclusion analyses and petrologic modelling then allow to calculate volatile fluxes as 1.02-14.3 (6.2) Tg/Ma/m H2O, 0.02-0.45 (0.17) Tg/Ma/m CO2, and 0.07-0.34 (0.22) Tg/Ma/m Cl. The same approach yields long-term sulfur fluxes of 0.12-1.08 (0.54) Tg/Ma/m while present-day open-vent SO2-flux monitoring yields 0.06-2.37 (0.83) Tg/Ma/m S. Input-output comparisons show that the arc water fluxes only account for up to 40 % of the input even if we include an "invisible" plutonic component constrained by crustal growth. With 20-30 % of the H2O input transferred into the deeper mantle as suggested by petrologic modeling, there remains a deficiency of, say, 30-40 % in the water budget. At least some of this water is transferred into two upper-plate regions of low seismic velocity and electrical resistivity whose sizes vary along arc: one region widely envelopes the melt ascent paths from slab top to arc and the other extends obliquely from the slab below the forearc to below the arc. Whether these reservoirs are transient or steady remains unknown.
KW  - Subduction input
KW  - Forearc dewatering
KW  - Arc magmatism
KW  - Subduction fluids
Y1  - 2014
U6  - https://doi.org/10.1007/s00531-014-1001-1
SN  - 1437-3254
SN  - 1437-3262
VL  - 103
IS  - 7
SP  - 2101
EP  - 2127
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Maslin, Mark A.
A1  - Brierley, Chris M.
A1  - Milner, Alice M.
A1  - Shultz, Susanne
A1  - Trauth, Martin H.
A1  - Wilson, Katy E.
T1  - East African climate pulses and early human evolution
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Current evidence suggests that all of the major events in hominin evolution have occurred in East Africa. Over the last two decades, there has been intensive work undertaken to understand African palaeoclimate and tectonics in order to put together a coherent picture of how the environment of East Africa has varied in the past. The landscape of East Africa has altered dramatically over the last 10 million years. It has changed from a relatively flat, homogenous region covered with mixed tropical forest, to a varied and heterogeneous environment, with mountains over 4 km high and vegetation ranging from desert to cloud forest. The progressive rifting of East Africa has also generated numerous lake basins, which are highly sensitive to changes in the local precipitation-evaporation regime. There is now evidence that the presence of precession-driven, ephemeral deep-water lakes in East Africa were concurrent with major events in hominin evolution. It seems the unusual geology and climate of East Africa created periods of highly variable local climate, which, it has been suggested could have driven hominin speciation, encephalisation and dispersal out of Africa. One example is the significant hominin speciation and brain expansion event at -1.8 Ma that seems to have been coeval with the occurrence of highly variable, extensive, deep-water lakes. This complex, climatically very variable setting inspired first the variability selection hypothesis, which was then the basis for the pulsed climate variability hypothesis. The newer of the two suggests that the long-term drying trend in East Africa was punctuated by episodes of short, alternating periods of extreme humidity and aridity. Both hypotheses, together with other key theories of climate-evolution linkages, are discussed in this paper. Though useful the actual evolution mechanisms, which led to early hominins are still unclear and continue to be debated. However, it is clear that an understanding of East African lakes and their palaeoclimate history is required to understand the context within which humans evolved and eventually left East Africa. (C) 2014 The Authors. Published by Elsevier Ltd.
KW  - Human evolution
KW  - East Africa
KW  - Palaeoclimatology
KW  - Palaeoliminology
KW  - Tectonics
KW  - Hominin
KW  - Orbital forcing
KW  - Cenozoic climate transitions
KW  - Pulsed climate variability hypothesis
Y1  - 2014
U6  - https://doi.org/10.1016/j.quascirev.2014.06.012
SN  - 0277-3791
VL  - 101
SP  - 1
EP  - 17
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - INPR
A1  - Freundt, A.
A1  - Halama, Ralf
A1  - Suess, E.
A1  - Voelker, D.
T1  - Introduction to the special issue on SFB 574 "Volatiles and fluids in subduction zones: climate feedback and trigger mechanisms for natural disasters"
T2  - International journal of earth sciences
Y1  - 2014
U6  - https://doi.org/10.1007/s00531-014-1059-9
SN  - 1437-3254
SN  - 1437-3262
VL  - 103
IS  - 7
SP  - 1729
EP  - 1731
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Garcin, Yannick
A1  - Schefuss, Enno
A1  - Schwab, Valerie F.
A1  - Garreta, Vincent
A1  - Gleixner, Gerd
A1  - Vincens, Annie
A1  - Todou, Gilbert
A1  - Sene, Olivier
A1  - Onana, Jean-Michel
A1  - Achoundong, Gaston
A1  - Sachse, Dirk
T1  - Reconstructing C-3 and C-4 vegetation cover using n-alkane carbon isotope ratios in recent lake sediments from Cameroon, Western Central Africa
JF  - Geochimica et cosmochimica acta : journal of the Geochemical Society and the Meteoritical Society
N2  - Trees and shrubs in tropical Africa use the C-3 cycle as a carbon fixation pathway during photosynthesis, while grasses and sedges mostly use the C-4 cycle. Leaf-wax lipids from sedimentary archives such as the long-chain n-alkanes (e.g., n-C-27 to n-C-33) inherit carbon isotope ratios that are representative of the carbon fixation pathway. Therefore, n-alkane delta C-13 values are often used to reconstruct past C-3/C-4 composition of vegetation, assuming that the relative proportions of C-3 and C-4 leaf waxes reflect the relative proportions of C-3 and C-4 plants. We have compared the delta C-13 values of n-alkanes from modern C-3 and C-4 plants with previously published values from recent lake sediments and provide a framework for estimating the fractional contribution (areal-based) of C-3 vegetation cover (f(C3)) represented by these sedimentary archives. Samples were collected in Cameroon, across a latitudinal transect that accommodates a wide range of climate zones and vegetation types, as reflected in the progressive northward replacement of C-3-dominated rain forest by C-4-dominated savanna. The C-3 plants analysed were characterised by substantially higher abundances of n-C-29 alkanes and by substantially lower abundances of n-C-33 alkanes than the C-4 plants. Furthermore, the sedimentary delta C-13 values of n-C-29 and n-C-31 alkanes from recent lake sediments in Cameroon (-37.4%) to 26.5%) were generally within the range of delta C-13 values for C-3 plants, even when from sites where C-4 plants dominated the catchment vegetation. In such cases simple linear mixing models fail to accurately reconstruct the relative proportions of C-3 and C-4 vegetation cover when using the delta C-13 values of sedimentary n-alkanes, overestimating the proportion of C-3 vegetation, likely as a consequence of the differences in plant wax production, preservation, transport, and/or deposition between C-3 and C-4 plants. We therefore tested a set of non-linear binary mixing models using delta C-13 values from both C-3 and C-4 vegetation as end-members. The non-linear models included a sigmoid function (sine-squared) that describes small variations in the f(C3) values as the minimum and maximum delta C-13 values are approached, and a hyperbolic function that takes into account the differences between C-3 and C-4 plants discussed above. Model fitting and the estimation of uncertainties were completed using the Monte Carlo algorithm and can be improved by future data addition. Models that provided the best fit with the observed delta C-13 values of sedimentary n-alkanes were either hyperbolic functions or a combination of hyperbolic and sine-squared functions. Such non-linear models may be used to convert delta C-13 measurements on sedimentary n-alkanes directly into reconstructions of C-3 vegetation cover. (C) 2014 Elsevier Ltd. All rights reserved.
Y1  - 2014
U6  - https://doi.org/10.1016/j.gca.2014.07.004
SN  - 0016-7037
SN  - 1872-9533
VL  - 142
SP  - 482
EP  - 500
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Zhao, Peng
A1  - Kuhn, Daniela
A1  - Oye, Volker
A1  - Cesca, Simone
T1  - Evidence for tensile faulting deduced from full waveform moment tensor inversion during the stimulation of the Basel enhanced geothermal system
JF  - Geothermics : an international journal of geothermal research and its applications
N2  - Our study presents the results of a moment tensor inversion of 19 microseismic events with M-L between 2.0 and 3.4, associated with the stimulation operation of an enhanced geothermal reservoir in Basel, Switzerland, in 2006. We adopt a three-step procedure to retrieve point source solution parameters based on full waveform inversion. The inversion is performed by fitting displacement amplitude spectra and displacement seismograms in the first and second step, respectively, assuming a double couple source model and thus obtaining focal solutions for all 19 events. Our results are in agreement with focal mechanisms from a previous study, which employed P wave first-motion polarities from more than 40 stations, whereas our solutions are achieved using full waveform data recorded by less than 10 surface stations. In the last step, a full moment tensor inversion is performed. The results from the moment tensor inversion show an improvement on the waveform fitting compared to the double couple models, which is verified by an F-test. We investigate the stability of the moment tensor solutions by employing different velocity models. The isotropic components of the moment tensor solutions of some events are not negligible, suggesting source volume changes due to fluid injection. Events with significant isotropic components occurred mainly during the stimulation phase and close to the injection well. On the other hand, events that occurred in the post-stimulation phase are predominantly pure shear failure and located further away from the well bore. These spatio-temporal patterns can be explained by the influence of pore pressure variations during and after the hydraulic stimulation at the geothermal site. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Induced seismicity
KW  - Hydraulic fracture
KW  - Crack opening and closure
KW  - Source mechanism
KW  - F-test
Y1  - 2014
U6  - https://doi.org/10.1016/j.geothermics.2014.01.003
SN  - 0375-6505
SN  - 1879-3576
VL  - 52
SP  - 74
EP  - 83
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Wolff, Christian Michael
A1  - Kristen-Jenny, Iris
A1  - Schettler, Georg
A1  - Plessen, Birgit
A1  - Meyer, Hanno
A1  - Dulski, Peter
A1  - Naumann, Rudolf
A1  - Brauer, Achim
A1  - Verschuren, Dirk
A1  - Haug, Gerald H.
T1  - Modern seasonality in Lake Challa (Kenya/Tanzania) and its sedimentary documentation in recent lake sediments
JF  - Limnology and oceanography
N2  - From November 2006 to January 2010, a sediment trap that was cleared monthly was deployed in Lake Challa, a deep stratified freshwater lake on the eastern slope of Mt. Kilimanjaro in southern Kenya. Geochemical data from sediment trap samples were compared with a broad range of limnological and meteorological parameters to characterize the effect of single parameters on productivity and sedimentation processes in the crater basin. During the southern hemisphere summer (November-March), when the water temperature is high and the lake is biologically productive (nondiatom algae), calcite predominated in the sediment trap samples. During the "long rain" season (March-May) a small amount of organic matter and lithogenic material caused by rainfall appeared. This was followed by the cool and windy months of the southern hemisphere winter (June-October) when diatoms were the main component, indicating a diatom bloom initiated by improvement of nutrient availability related to upwelling processes. The sediment trap data support the hypothesis that the light-dark lamination couplets, which are abundant in Lake Challa cores, reflect seasonal delivery to the sediments of diatom-rich particulates during the windy months and diatom-poor material during the wet season. However, interannual and spatial variability in upwelling and productivity patterns, as well as El Nino-Southern Oscillation (ENSO)-related rainfall and drought cycles, exert a strong influence on the magnitude and geochemical composition of particle export to the hypolimnion of Lake Challa.
Y1  - 2014
U6  - https://doi.org/10.4319/lo.2014.59.5.1621
SN  - 0024-3590
SN  - 1939-5590
VL  - 59
IS  - 5
SP  - 1621
EP  - 1636
PB  - Wiley
CY  - Waco
ER  - 
TY  - JOUR
A1  - Albrich, Sergi
A1  - Frijia, Gianluca
A1  - Parente, Mariano
A1  - Caus, Esmeralda
T1  - The evolution of the earliest representatives of the genus Orbitoides: Implications for Upper Cretaceous biostratigraphy
JF  - Cretaceous research
N2  - The biostratigraphy of Campanian-Maastrichtian carbonate platforms is largely based on the larger foraminiferal genus Orbitoides. However, while the taxonomy and the chronostratigraphic age of the younger species of this genus are well established, there are still many controversies on the earliest species. We have restudied their morphological characters using a large collection of samples from the type-localities and from continuous sections in the southern Pyrenees. Based on these new observations, the long forgotten species O. sanctae-pelagiae is reinstated, while O. dordoniensis is considered a junior synonym. Successive populations of O. hottingeri, O. sanctae-pelagiae and O. douvillei show gradual morphological changes in time marked by an increase in the size and complexity of the macrospheric embryonal apparatus, an increase of the size of the adult specimens of both generations and the progressive appearance and development of true lateral chamberlets. The Font de les Bagasses Unit in the southern Pyrenees preserves a high-resolution archive of the evolution of the earliest Orbitoides. Strontium isotope stratigraphy indicates that the oldest species, O. hottingeri, made its first appearance in the earliest Campanian, close to the Santonian-Campanian boundary, and was replaced by O. sanctae-pelagiae at a level closely corresponding to the boundary between the Placenticeras bidorsatum and Menabites delawarensis ammonite zones. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Larger foraminifera
KW  - Biostratigraphy
KW  - Strontium isotope stratigraphy
KW  - Late cretaceous
KW  - Orbitoides
Y1  - 2014
U6  - https://doi.org/10.1016/j.cretres.2014.04.013
SN  - 0195-6671
SN  - 1095-998X
VL  - 51
SP  - 22
EP  - 34
PB  - Elsevier
CY  - London
ER  - 
TY  - JOUR
A1  - Dietze, Elisabeth
A1  - Maussion, F.
A1  - Ahlborn, M.
A1  - Diekmann, Bernhard
A1  - Hartmann, K.
A1  - Henkel, K.
A1  - Kasper, T.
A1  - Lockot, G.
A1  - Opitz, S.
A1  - Haberzettl, T.
T1  - Sediment transport processes across the Tibetan Plateau inferred from robust grain-size end members in lake sediments
JF  - Climate of the past : an interactive open access journal of the European Geosciences Union
N2  - Grain-size distributions offer powerful proxies of past environmental conditions that are related to sediment sorting processes. However, they are often of multimodal character because sediments can get mixed during deposition. To facilitate the use of grain size as palaeoenvironmental proxy, this study aims to distinguish the main detrital processes that contribute to lacustrine sedimentation across the Tibetan Plateau using grain-size end-member modelling analysis. Between three and five robust grain-size end-member subpopulations were distinguished at different sites from similarly-likely end-member model runs. Their main modes were grouped and linked to common sediment transport and depositional processes that can be associated with contemporary Tibetan climate (precipitation patterns and lake ice phenology, gridded wind and shear stress data from the High Asia Reanalysis) and local catchment configurations. The coarse sands and clays with grain-size modes > 250 mu m and < 2 mu m were probably transported by fluvial processes. Aeolian sands (similar to 200 mu m) and coarse local dust (similar to 60 mu m), transported by saltation and in near-surface suspension clouds, are probably related to occasional westerly storms in winter and spring. Coarse regional dust with modes similar to 25 mu m may derive from near-by sources that keep in longer term suspension. The continuous background dust is differentiated into two robust end members (modes: 5-10 and 2-5 mu m) that may represent different sources, wind directions and/or sediment trapping dynamics from long-range, upper-level westerly and episodic northerly wind transport. According to this study grain-size end members of only fluvial origin contribute small amounts to mean Tibetan lake sedimentation (19 +/- 5%), whereas local to regional aeolian transport and background dust deposition dominate the clastic sedimentation in Tibetan lakes (contributions: 42 +/- 14% and 51 +/- 11%). However, fluvial and alluvial reworking of aeolian material from nearby slopes during summer seems to limit end-member interpretation and should be cross-checked with other proxy information. If not considered as a stand-alone proxy, a high transferability to other regions and sediment archives allows helpful reconstructions of past sedimentation history.
Y1  - 2014
U6  - https://doi.org/10.5194/cp-10-91-2014
SN  - 1814-9324
SN  - 1814-9332
VL  - 10
IS  - 1
SP  - 91
EP  - 106
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Fahle, Marcus
A1  - Dietrich, Ottfried
T1  - Estimation of evapotranspiration using diurnal groundwater level fluctuations: Comparison of different approaches with groundwater lysimeter data
JF  - Water resources research
N2  - In wetlands or riparian areas, water withdrawal by plants with access to groundwater or the capillary fringe often causes diurnal groundwater fluctuations. Various approaches use the characteristics of these fluctuations for estimation of daily groundwater evapotranspiration rates. The objective of this paper was to review the available methods, compare them with measured evapotranspiration and assess their recharge assumptions. For this purpose, we employed data of 85 rain-free days of a weighable groundwater lysimeter situated at a grassland site in the Spreewald wetland in north-east Germany. Measurements of hourly recharge and daily evapotranspiration rates were used to assess the different approaches. Our results showed that a maximum of 50% of the day to day variance of the daily evapotranspiration rates could be explained by the approaches based on groundwater fluctuations. Simple and more complex methods performed similarly. For some of the approaches, there were indications that erroneous assumptions compensated each other (e.g., when overestimated recharge counteracted underestimated storage change). We found that the usage of longer time spans resulted in improved estimates of the daily recharge rates and that the estimates were further enhanced by including two night averages. When derived from fitting estimates of recharge or evapotranspiration with according measurements the specific yield, needed to convert changes in water level to water volumes, differed considerably among the methods (from 0.022 to 0.064). Thus, the specific yield can be seen as correction factor that compensates for inadequate process descriptions.
KW  - evapotranspiration
KW  - groundwater lysimeter
KW  - specific yield
KW  - diurnal signal
KW  - phreatophytes
KW  - wetland
Y1  - 2014
U6  - https://doi.org/10.1002/2013WR014472
SN  - 0043-1397
SN  - 1944-7973
VL  - 50
IS  - 1
SP  - 273
EP  - 286
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Basavaiah, Nathani
A1  - Wiesner, M. G.
A1  - Anoop, Ambili
A1  - Menzel, P.
A1  - Nowaczyk, Norbert R.
A1  - Deenadayalan, K.
A1  - Brauer, Achim
A1  - Gaye, Birgit
A1  - Naumann, R.
A1  - Riedel, N.
A1  - Stebich, M.
A1  - Prasad, Sushma
T1  - Physicochemical analyses of surface sediments from the Lonar Lake, central India - implications for palaeoenvironmental reconstruction
JF  - Fundamental and applied limnology : official journal of the International Association of Theoretical and Applied Limnology
N2  - We report the results of our investigations on the catchment area, surface sediments, and hydrology of the monsoonal Lonar Lake, central India. Our results indicate that the lake is currently stratified with an anoxic bottom layer, and there is a spatial heterogeneity in the sensitivity of sediment parameters to different environmental processes. In the shallow (0-5 m) near shore oxic-suboxic environments the lithogenic and terrestrial organic content is high and spatially variable, and the organics show degradation in the oxic part. Due to aerial exposure resulting from lake level changes of at least 3m, the evaporitic carbonates are not completely preserved. In the deep water (>5 m) anoxic environment the lithogenics are uniformly distributed and the delta C-13 is an indicator not only for aquatic vs. terrestrial plants but also of lake pH and salinity. The isotopic composition of the evaporites is dependent not only on the isotopic composition of source water (monsoon rainfall and stream inflow) and evaporation, but is also influenced by proximity to the isotopically depleted stream inflow. We conclude that in the deep water environment lithogenic content, and isotopic composition of organic matter can be used for palaeoenvironmental reconstruction.
KW  - isotopes
KW  - lonar lake
KW  - modern surface sediments
KW  - magnetic parameters
KW  - monsoon
KW  - palaeoenvironmental proxies
Y1  - 2014
U6  - https://doi.org/10.1127/1863-9135/2014/0515
SN  - 1863-9135
VL  - 184
IS  - 1
SP  - 51
EP  - 68
PB  - Schweizerbart
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Nishihara, Yu
A1  - Ohuchi, Tomohiro
A1  - Kawazoe, Takaaki
A1  - Spengler, Dirk
A1  - Tasaka, Miki
A1  - Kikegawa, Takumi
A1  - Suzuki, Akio
A1  - Ohtani, Eiji
T1  - Rheology of fine-grained forsterite aggregate at deep upper mantle conditions
JF  - Journal of geophysical research : Solid earth
KW  - high-pressure
KW  - olivine
KW  - rheology
KW  - upper mantle
Y1  - 2014
U6  - https://doi.org/10.1002/2013JB010473
SN  - 2169-9313
SN  - 2169-9356
VL  - 119
IS  - 1
SP  - 253
EP  - 273
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Farinotti, Daniel
A1  - King, Edward C.
A1  - Albrecht, Anika
A1  - Huss, Matthias
A1  - Gudmundsson, Gudmundur Hilmar
T1  - The bedrock topography of Starbuck Glacier, Antarctic Peninsula, as determined by radio-echo soundings and flow modeling
JF  - Annals of glaciology
KW  - Antarctic glaciology
KW  - glaciological instruments and methods
KW  - ground-penetrating radar
KW  - ice-shelf tributary glaciers
KW  - radio-echo sounding
Y1  - 2014
U6  - https://doi.org/10.3189/2014AoG67A025
SN  - 0260-3055
SN  - 1727-5644
VL  - 55
IS  - 67
SP  - 22
EP  - 28
PB  - International Glaciological Society
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Müller, Hans J.
A1  - Beckmann, Felix
A1  - Dobson, David P.
A1  - Hunt, Simon A.
A1  - Lathe, Christian
A1  - Stroncik, Nicole
T1  - New techniques for high pressure falling sphere viscosimetry in DIA-type large volume presses
JF  - High pressure research
KW  - falling sphere viscosimetry
KW  - inelastic properties
KW  - high pressure
KW  - X-radiography
Y1  - 2014
U6  - https://doi.org/10.1080/08957959.2014.950262
SN  - 0895-7959
SN  - 1477-2299
VL  - 34
IS  - 3
SP  - 345
EP  - 354
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Kneis, David
A1  - Chatterjee, C.
A1  - Singh, R.
T1  - Evaluation of TRMM rainfall estimates over a large Indian river basin (Mahanadi)
JF  - Hydrology and earth system sciences : HESS
N2  - The paper examines the quality of satellite-abased precipitation estimates for the lower Mahanadi River basin (eastern India). The considered data sets known as 3B42 and 3B42-RT (version 7/7A) are routinely produced by the tropical rainfall measuring mission (TRMM) from passive microwave and infrared recordings. While the 3B42-RT data are disseminated in real time, the gauge-aadjusted 3B42 data set is published with a delay of some months. The quality of the two products was assessed in a two-astep procedure. First, the correspondence between the remotely sensed precipitation rates and rain gauge data was evaluated at the subbasin scale. Second, the quality of the rainfall estimates was assessed by analysing their performance in the context of rainfall-arunoff simulation.
 At sub-abasin level (4000 to 16 000 km(2)) the satellite-abased areal precipitation estimates were found to be moderately correlated with the gauge-abased counterparts (R-2 of 0.64-0.74 for 3B42 and 0.59-0.72 for 3B42-RT). Significant discrepancies between TRMM data and ground observations were identified at high-aintensity levels. The rainfall depth derived from rain gauge data is often not reflected by the TRMM estimates (hit rate < 0.6 for ground-abased intensities > 80 mm day(-1)). At the same time, the remotely sensed rainfall rates frequently exceed the gauge-abased equivalents (false alarm ratios of 0.2-0.6). In addition, the real-atime product 3B42-RT was found to suffer from a spatially consistent negative bias.
 Since the regionalisation of rain gauge data is potentially associated with a number of errors, the above results are subject to uncertainty. Hence, a validation against independent information, such as stream flow, was essential. In this case study, the outcome of rainfall-arunoff simulation experiments was consistent with the above-mentioned findings. The best fit between observed and simulated stream flow was obtained if rain gauge data were used as model input (Nash-Sutcliffe index of 0.76-0.88 at gauges not affected by reservoir operation). This compares to the values of 0.71-0.78 for the gauge-djusted TRMM 3B42 data and 0.65-0.77 for the 3B42-RT real-atime data. Whether the 3B42-RT data are useful in the context of operational runoff prediction in spite of the identified problems remains a question for further research.
Y1  - 2014
U6  - https://doi.org/10.5194/hess-18-2493-2014
SN  - 1027-5606
SN  - 1607-7938
VL  - 18
IS  - 7
SP  - 2493
EP  - 2502
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Nussbaumer, S.
A1  - Schaub, Y.
A1  - Huggel, C.
A1  - Walz, Ariane
T1  - Risk estimation for future glacier lake outburst floods based on local land-use changes
JF  - Natural hazards and earth system sciences
N2  - Effects of climate change are particularly strong in high-mountain regions. Most visibly, glaciers are shrinking at a rapid pace, and as a consequence, glacier lakes are forming or growing. At the same time the stability of mountain slopes is reduced by glacier retreat, permafrost thaw and other factors, resulting in an increasing landslide hazard which can potentially impact lakes and therewith trigger far-reaching and devastating outburst floods. To manage risks from existing or future lakes, strategies need to be developed to plan in time for adequate risk reduction measures at a local level. However, methods to assess risks from future lake outbursts are not available and need to be developed to evaluate both future hazard and future damage potential.
 Here a method is presented to estimate future risks related to glacier lake outbursts for a local site in southern Switzerland (Naters, Valais). To generate two hazard scenarios, glacier shrinkage and lake formation modelling was applied, combined with simple flood modelling and field work. Furthermore, a land-use model was developed to quantify and allocate land-use changes based on local-to-regional storylines and three scenarios of land-use driving forces. Results are conceptualized in a matrix of three land-use and two hazard scenarios for the year 2045, and show the distribution of risk in the community of Naters, including high and very high risk areas. The study underlines the importance of combined risk management strategies focusing on land-use planning, on vulnerability reduction, as well as on structural measures (where necessary) to effectively reduce future risks related to lake outburst floods.
Y1  - 2014
U6  - https://doi.org/10.5194/nhess-14-1611-2014
SN  - 1561-8633
VL  - 14
IS  - 6
SP  - 1611
EP  - 1624
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Menges, Johanna
A1  - Huguet, C.
A1  - Alcaniz, Josep M.
A1  - Fietz, Susanne
A1  - Sachse, Dirk
A1  - Rosell-Mele, A.
T1  - Influence of water availability in the distributions of branched glycerol dialkyl glycerol tetraether in soils of the Iberian Peninsula
JF  - Biogeosciences
Y1  - 2014
U6  - https://doi.org/10.5194/bg-11-2571-2014
SN  - 1726-4170
SN  - 1726-4189
VL  - 11
IS  - 10
SP  - 2571
EP  - 2581
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Huck, Stefan
A1  - Stein, Melody
A1  - Immenhauser, Adrian
A1  - Skelton, Peter W.
A1  - Christ, Nicolas
A1  - Foellmi, Karl B.
A1  - Heimhofer, Ulrich
T1  - Response of proto-North Atlantic carbonate-platform ecosystems to OAE1a-related stressors
JF  - Sedimentary geology : international journal of applied and regional sedimentology
N2  - Integrated biostratigraphic-chemostratigraphic studies provide evidence that the proto-North Atlantic realm witnessed major changes in carbonate platform production in the run-up of the Early Aptian oceanic anoxic event (OAE) 1a. Whereas pervasive growth of Lithocodium microencrusters represents an early harbinger of OAE1a-related environmental perturbation, the subsequent replacement of oligotrophic rudist-coral-nerineid by mesotrophic orbitolinid-oyster communities was clearly associated with the event itself. In order to test the supra-regional relevance of this major community replacement, two shallow-water sections in the southern Lusitanian Basin (Portugal) are investigated by means of geochemistry (carbon and oxygen isotopes), cement petrography and detailed sedimentological analysis. The focus is on a regional, prominent discontinuity surface (S4) at the transition between oligotrophic and mesotrophic carbonate platform production, which might indicate that the major biotic change could have been associated with a phase of non-sedimentation and possibly erosion. The studied sections (Sao Julia, Crismina) provide evidence that the major Early Aptian biotic turnover was preceded by numerous subordinate but significant changes in platform ecology, which mirrored a series of progressive short-term environmental changes in the course of OAE1. Several transient mass occurrences of orbitolinids indicate repeated phases of ecological stress arguably due to enhanced nutrient input and deepening. Small-scale sea-level changes at parasequence level below the major discontinuity surface are revealed by alternations of rudist assemblages dominated by clinger or recumbent forms as well as intercalated hardground and subaerial exposure stages. Expanded phases of subaerial exposure, however, can be largely ruled out following the geochemical and cement-petrographic data presented here. Enhanced continent-derived siliciclastic input characterising the lower orbitolinid-oyster dominated limestones is in support of a shift to more humid conditions during the middle Early Aptian. This is in line with palaeoclimatic data, which propose a southward movement of the mid-latitude arid climate belt during this time. The documented rapid replacement of oligotrophic assemblages by various environmental-stress adapted carbonate platform communities might be seen as explanation for ongoing Early Aptian proto-North Atlantic carbonate production during a time of widespread platform demise and drowning in the northern Tethyan realm. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Aptian
KW  - Oceanic anoxic event 1a
KW  - Proto-North Atlantic
KW  - Discontinuity surfaces
KW  - Carbonate platform response
KW  - Carbon and oxygen isotopes
Y1  - 2014
U6  - https://doi.org/10.1016/j.sedgeo.2014.08.003
SN  - 0037-0738
SN  - 1879-0968
VL  - 313
SP  - 15
EP  - 31
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Polanski, Stefan
A1  - Fallah, Bijan
A1  - Befort, Daniel J.
A1  - Prasad, Sushma
A1  - Cubasch, Ulrich
T1  - Regional moisture change over India during the past millennium: A comparison of multi-proxy reconstructions and climate model simulations
JF  - Global and planetary change
N2  - The Indian Monsoon Variability during the past Millennium has been simulated with the ECHAM5 model in two different time slices: Medieval Climate Anomaly and the Little Ice Age. The simulations are compared with new centennial-resolving paleo-reconstructions inferred from various well-dated multi-proxies from two core regions, the Himalaya and Central India. A qualitative moisture index is derived from the proxies and compared with simulated moisture anomalies.
 The reconstructed paleo-hydrological changes between the Little Ice Age and the Medieval Climate Anomaly depict a dipole pattern between Himalaya and Central India, which is also captured by the model.
 In the Medieval Climate Anomaly the model exhibits stronger (weaker) dipole signals during summer (winter) compared to Little Ice Age. In summer (winter) months of "Medieval Climate Anomaly minus Little Ice Age" the model simulates wetter conditions over eastern (western and central) Himalaya. Over Central India, a simulated weakening of Indian Summer Monsoon during warmer climate is coincident with reconstructed drying signal in the Lonar Lake record.
 Based on the model simulations, we can differentiate three physical mechanisms which can lead to the moisture anomalies: (i) the western and central Himalaya are influenced by extra-tropical Westerlies during winter, (ii) the eastern Himalaya is affected by summer variations of temperature gradient between Bay of Bengal and Indian subcontinent and by a zonal band of intensified Indian-East Asian monsoon link north of 25 degrees N, and (iii) Central India is dominated by summer sea surface temperature anomalies in the northern Arabian Sea which have an effect on the large-scale advection of moist air masses. The temperatures in the Arabian Sea are linked to the Ind Pacific Warm Pool, which modulates the Indian monsoon strength. (C) 2014 The Authors. Published by Elsevier B.V.
KW  - Medieval Climate Anomaly
KW  - Little Ice Age
KW  - moisture variations in India
KW  - atmosphere-only climate model simulations
KW  - Lonar Crater Lake
KW  - multi-proxy reconstructions
Y1  - 2014
U6  - https://doi.org/10.1016/j.gloplacha.2014.08.016
SN  - 0921-8181
SN  - 1872-6364
VL  - 122
SP  - 176
EP  - 185
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mischke, Steffen
A1  - Ashkenazi, Shoshana
A1  - Almogi-Labin, Ahuva
A1  - Goren-Inbar, Naama
T1  - Ostracod evidence for the Acheulian environment of the ancient Hula Lake (Levant) during the early-mid Pleistocene transition
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - Ostracod shells from the archaeological site Gesher BenotYa'aqov (GBY) in the upper Jordan River Valley (Israel) were investigated to improve the understanding of the environmental conditions of the Acheulian occupation site during the early-mid Pleistocene transition (0.78 Ma). The diverse ostracod assemblage consists of 28 species. The distribution of most of the recorded species in the region today shows that the hydrological conditions at the early-mid Pleistocene transition were not fundamentally different from the modern ones. However, the predominance of Candona neglecta shells in the GBY sequence probably indicates cooler climatic conditions than today. Shells of Candona angulata in the artefact-richer upper half of the sequence suggest a slight salinity increase in the ancient Hula Lake from pure freshwater to slightly oligohaline conditions. This shift probably resulted from wetter conditions and a more stable lake environment with increased residence time of the lake water and stronger influence of evaporation. Shells of the brackish water ostracod Cyprideis torosa and the slightly halophilic Heterocypris sauna and Plesiocypridopsis newtoni were recorded only rarely suggesting that the lake maintained an outlet through the entire period represented by the GBY sequence. Shells of Gomphocythere ortali in GBY cycles 1 and 2 imply that a permanent freshwater stream existed close to the site. Humphcypris subterranea shells in cycles 3-5 provide further evidence that a tributary entered the lake from the south in contrast to the modern setting with the north-south flowing Jordan River at GBY. Statistical analysis of the quantitative ostracod data from GBY identified a group of samples from layers containing more abundant stone artefacts and another group of samples from layers with scarce artefacts. Samples from layers containing more abundant artefacts have relatively high abundances of C. angulata, Darwinula stevensoni and Physocypria kraepelini shells and include rare shells of Ilyocypris hartmanni, Ilyocypris salebrosa, Heterocypris incongniens and Pseudocandona sp. 2 which do not occur in the other samples. The presence of P. kraepelini and H. incongruens shells in artefact-richer sediments possibly indicates poor bottom water oxygenation in the ancient Hula lake sometimes during the periods of Acheulian occupation. However, more detailed studies are required to assess whether lower dissolved oxygen levels in the lake resulted from a slight lake level rise and possibly higher nutrient flux to the lake during wetter conditions or whether hominins already impacted lake's nutrient status by butchering at its shore or by burning of near-shore vegetation. (c) 2014 Elsevier B.V. All rights reserved.
KW  - Levant
KW  - Israel
KW  - Acheulian
KW  - Lower Palaeolithic
KW  - Ostracods
KW  - Palaeoecology
Y1  - 2014
U6  - https://doi.org/10.1016/j.palaeo.2014.07.036
SN  - 0031-0182
SN  - 1872-616X
VL  - 412
SP  - 148
EP  - 159
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Konrad-Schmolke, Matthias
A1  - Halama, Ralf
T1  - Combined thermodynamic-geochemical modeling in metamorphic geology: Boron as tracer of fluid-rock interaction
JF  - Lithos : an international journal of mineralogy, petrology, and geochemistry
N2  - Quantitative geochemical modeling is today applied in a variety of geological environments from the petrogenesis of igneous rocks to radioactive waste disposal. In addition, the development of thermodynamic databases and computer programs to calculate equilibrium phase diagrams has greatly advanced our ability to model geodynamic processes. Combined with experimental data on elemental partitioning and isotopic fractionation, thermodynamic forward modeling unfolds enormous capacities that are far from exhausted.
 In metamorphic petrology the combination of thermodynamic and trace element forward modeling can be used to study and to quantify processes at spatial scales from mu m to km. The thermodynamic forward models utilize Gibbs energy minimization to quantify mineralogical changes along a reaction path of a chemically open fluid/rock system. These results are combined with mass balanced trace element calculations to determine the trace element distribution between rock and melt/fluid during the metamorphic evolution. Thus, effects of mineral reactions, fluid-rock interaction and element transport in metamorphic rocks on the trace element and isotopic composition of minerals, rocks and percolating fluids or melts can be predicted.
 Here we illustrate the capacities of combined thermodynamic-geochemical modeling based on two examples relevant to mass transfer during metamorphism. The first example focuses on fluid-rock interaction in and around a blueschist-facies shear zone in felsic gneisses, where fluid-induced mineral reactions and their effects on boron (B) concentrations and isotopic compositions in white mica are modeled. In the second example, fluid release from a subducted slab, the associated transport of B as well as variations in B concentrations and isotopic compositions in liberated fluids and residual rocks are modeled. We compare the modeled results of both examples to geochemical data of natural minerals and rocks and demonstrate that the combination of thermodynamic and geochemical models enables quantification of metamorphic processes and insights into element cycling that would have been unattainable if only one model approach was chosen. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Thermodynamic-geochemical modeling
KW  - Fluid-rock interaction
KW  - Subduction
KW  - Dehydration
KW  - Boron isotopes
Y1  - 2014
U6  - https://doi.org/10.1016/j.lithos.2014.09.021
SN  - 0024-4937
SN  - 1872-6143
VL  - 208
SP  - 393
EP  - 414
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Rehman, Hafiz Ur
A1  - Tanaka, Ryoji
A1  - Kobayashi, Katsura
A1  - Tsujimori, Tatsuki
A1  - Nakamura, Eizo
A1  - Yamamoto, Hiroshi
A1  - Khan, Tahseenullah
A1  - Kaneko, Yoshiyuki
T1  - Oxygen isotopes in Indian Plate eclogites (Kaghan Valley, Pakistan): Negative delta O-18 values from a high latitude protolith reset by Himalayan metamorphism
JF  - Lithos : an international journal of mineralogy, petrology, and geochemistry
N2  - Oxygen isotope compositions are reported for the first time for the Himalayan metabasites of the Kaghan Valley, Pakistan in this study. The highest metamorphic grades are recorded in the north of the valley, near the India-Asia collision boundary, in the form of high-pressure (HP: Group I) and ultrahigh-pressure (UHP: Group II) eclogites. The rocks show a step-wise decrease in grade from the UHP to HP eclogites and amphibolites. The protoliths of these metabasites were the Permian Panjal Trap basalts (ca. 267 +/- 2.4 Ma), which were emplaced along the northern margin of India when it was part of Gondwana. After the break-up of Gondwana, India drifted northward, subducted beneath Asia and underwent UHP metamorphism during the Eocene (ca. 45 +/- 1.2 Ma). At the regional scale, amphibolites, Group I and II eclogites yielded delta O-18 values of +5.84 and +5.91 parts per thousand, +1.66 to +424 parts per thousand, and -2.25 to +0.76 parts per thousand, respectively, relative to VSMOW. On a more local scale, within a single eclogite body, the delta O-18 values were the lowest (-2.25 to-1.44%.) in the central, the best preserved (least retrograded) parts, and show a systematic increase outward into more retrograded rocks, reaching up to +0.12 parts per thousand. These values are significantly lower than the typical mantle values for basalts of + 5.7 +/- 0.3 parts per thousand. The unusually low or negative delta O-18 values in Group II eclogites potentially resulted from hydrothermal alteration of the protoliths by interactions with meteoric water when the Indian plate was at southern high latitudes (similar to 60 degrees S). The stepwise increase in delta O-18 values, among different eclogite bodies in general and at single outcrop-scales in particular, reflects differing degrees of resetting of the oxygen isotope compositions during exhumation-related retrogression. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Himalaya
KW  - Kaghan
KW  - UHP eclogites
KW  - Oxygen isotope compositions
KW  - Laser fluorination
Y1  - 2014
U6  - https://doi.org/10.1016/j.lithos.2014.09.007
SN  - 0024-4937
SN  - 1872-6143
VL  - 208
SP  - 471
EP  - 483
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Tu, Rui
A1  - Wang, Rongjiang
A1  - Walter, Thomas R.
A1  - Diao, FaQi
T1  - Adaptive recognition and correction of baseline shifts from collocated GPS and accelerometer using two phases Kalman filter
JF  - Advances in space research
N2  - The real-time recognition and precise correction of baseline shifts in strong-motion records is a critical issue for GPS and accelerometer combined processing. This paper proposes a method to adaptively recognize and correct baseline shifts in strong-motion records by utilizing GPS measurements using two phases Kalman filter. By defining four kinds of learning statistics and criteria, the time series of estimated baseline shifts can be divided into four time intervals: initialization, static, transient and permanent. During the time interval in which the transient baseline shift is recognized, the dynamic noise of the Kalman filter system and the length of the baseline shifts estimation window are adaptively adjusted to yield a robust integration solution. The validations from an experimental and real datasets show that acceleration baseline shifts can be precisely recognized and corrected, thus, the combined system adaptively adjusted the estimation strategy to get a more robust solution. (C) 2014 COSPAR. Published by Elsevier Ltd. All rights reserved.
KW  - GPS
KW  - Strong-motion
KW  - Baseline shift
KW  - Kalman filter
KW  - Integration
Y1  - 2014
U6  - https://doi.org/10.1016/j.asr.2014.07.008
SN  - 0273-1177
SN  - 1879-1948
VL  - 54
IS  - 9
SP  - 1924
EP  - 1932
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Huang, Xiangtong
A1  - Oberhaensli, Hedi
A1  - von Suchodoletz, Hans
A1  - Prasad, Sushma
A1  - Sorrel, Philippe
A1  - Plessen, Birgit
A1  - Mathis, Marie
A1  - Usubaliev, Raskul
T1  - Hydrological changes in western Central Asia (Kyrgyzstan) during the Holocene as inferred from a palaeolimnological study in lake Son Kul
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - The hydrology of western Central Asia is highly sensitive to climatic perturbations. In order to understand its long-term variability and to infer linkages between precipitation and atmospheric and oceanic systems, we conducted a thorough sedimentary and geochemical study on a composite core retrieved in lake Son Kul (central Kyrgyzstan). A multi-proxy approach was conducted on lake sediments based on grain size analyses, magnetic susceptibility, total organic carbon (TOC), total nitrogen (TN) and carbon and oxygen isotope analyses on bulk and biogenic materials (ostracoda and molluscs shells) at a resolution equivalent to ca 40 years, aiming to characterise the sequence of palaeolimnological changes in Son Kul.
 As indicated by delta O-18 record of bulk carbonates, mainly consisting of aragonite, the Holocene hydrological balance was negative during most of time, suggesting an excess of evaporation (E) over precipitation (P). Limnological conditions fluctuated rapidly before 5000 cal yr BP indicating significant changes in regional hydrology and climate. In particular, the long-term negative hydrological balance was impeded by several short stages with marked increase of precipitation, lasting several decades to a few centuries (e.g., 8300-8200, 6900-6700, 6300-6100, 5500-5400, 5300-5200 and 3100 -3000 cal yr BP). Precipitation changes as inferred from 8180 data are also documented by increased minerogenic detritus and higher TOC. We propose that the seasonal pattern of precipitation varied transiently in western Central Asia during the Holocene, although evaporation changes may also account for the rapid changes observed in delta O-18 data. When the annual water balance was less critical (P <= E), the excess of water might be ascribed to increased precipitation during cold seasons mainly because winter precipitation has more negative delta O-18 than its summer equivalent. Conversely, when the annual water balance is negative (P E), the moisture was mainly delivered during the warm season, as between 5000 and 2000 cal yr BP. Our results thus imply that moisture sources could have changed as well during the Holocene. Moisture was delivered as today mainly during summer from the extended Caspian-Aral Basin and eastern Mediterranean, although Arctic and even North Atlantic seas might be important moisture sources when seasonal precipitation was dominated by winter precipitation. We hypothesise that warming Arctic and North Atlantic seas were important for the North Hemisphere circulation during the cold season. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Holocene
KW  - Tien Shan (western Central Asia)
KW  - Oxygen and carbon isotopes
KW  - Hydrological balance
Y1  - 2014
U6  - https://doi.org/10.1016/j.quascirev.2014.09.012
SN  - 0277-3791
VL  - 103
SP  - 134
EP  - 152
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Sachse, Rene
A1  - Petzoldt, Thomas
A1  - Blumstock, Maria
A1  - Moreira, Santiago
A1  - Paetzig, Marlene
A1  - Ruecker, Jacqueline
A1  - Janse, Jan H.
A1  - Mooij, Wolf M.
A1  - Hilt, Sabine
T1  - Extending one-dimensional models for deep lakes to simulate the impact of submerged macrophytes on water quality
JF  - Environmental modelling & software with environment data news
N2  - Submerged macrophytes can stabilise clear water conditions in shallow lakes. However, many existing models for deep lakes neglect their impact. Here, we tested the hypothesis that submerged macrophytes can affect the water clarity in deep lakes. A one-dimensional, vertically resolved macrophyte model was developed based on PCLake and coupled to SALMO-1D and GOTM hydrophysics and validated against field data. Validation showed good coherence in dynamic growth patterns and colonisation depths. In our simulations the presence of submerged macrophytes resulted in up to 50% less phytoplankton biomass in the shallowest simulated lake (11 m) and still 15% less phytoplankton was predicted in 100 m deep oligotrophic lakes. Nutrient loading, lake depth, and lake shape had a strong influence on macrophyte effects. Nutrient competition was found to be the strongest biological interaction. Despite a number of limitations, the derived dynamic lake model suggests significant effects of submerged macrophytes on deep lake water quality. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Lake model
KW  - Macrophytes
KW  - Water quality
Y1  - 2014
U6  - https://doi.org/10.1016/j.envsoft.2014.05.023
SN  - 1364-8152
SN  - 1873-6726
VL  - 61
SP  - 410
EP  - 423
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Aich, Valentin
A1  - Zimmermann, Alexander
A1  - Elsenbeer, Helmut
T1  - Quantification and interpretation of suspended-sediment discharge hysteresis patterns: How much data do we need?
JF  - Catena : an interdisciplinary journal of soil science, hydrology, geomorphology focusing on geoecology and landscape evolution
N2  - Sediment-discharge hysteresis loops are frequently analyzed to facilitate the understanding of sediment transport processes. Hysteresis patterns, however, are often complex and their interpretation can be complicated. Particularly, quantifying hysteresis patterns remains a problematic issue. Moreover, it is currently unknown how much data is required for analyzing sediment-discharge hysteresis loops in a given area. These open questions and challenges motivated us to develop a new method for quantifying suspended-sediment hysteresis. Subsequently, we applied the new hysteresis index to three suspended-sediment and discharge datasets from a small tropical rainforest catchment. The datasets comprised a different number of events and sampling sites. Our analyses show three main findings: (1) datasets restricted to only few events, which is typical for rapid assessment surveys, were always sufficient to identify the dominating hysteresis pattern in our research area. Furthermore, some of these small datasets contained multiple-peak events that allowed identifying intra-event exhaustion effects and hence, limitations in sediment supply. (2) Datasets comprising complete hydrological years were particularly useful for analyzing seasonal dynamics of hysteresis. These analyses revealed an exhaustion of hysteresis on the inter-event scale which also points to a limited sediment supply. (3) Datasets comprising measurements from two consecutive gauges installed at the catchment outlet and on a slope within that catchment allowed analyzing the change of hysteresis patterns along the flowpath. On the slope, multiple-peak events showed a stronger intra-event exhaustion of hysteresis than at the catchment outlet. Furthermore, exhaustion of hysteresis on the inter-event scale was not evident on the slope but occurred at the catchment outlet. Our results indicate that even small sediment datasets can provide valuable insights into sediment transport processes of small catchments. Furthermore, our results may serve as a first guideline on what to expect from an analysis of hysteresis patterns for datasets of varying quality and quantity. (c) 2014 Elsevier B.V. All rights reserved.
KW  - Suspended sediment
KW  - Hysteresis index
KW  - Sediment monitoring
KW  - Overland flow
KW  - Tropical forest
Y1  - 2014
U6  - https://doi.org/10.1016/j.catena.2014.06.020
SN  - 0341-8162
SN  - 1872-6887
VL  - 122
SP  - 120
EP  - 129
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Dulanya, Zuze
A1  - Croudace, Ian
A1  - Reed, Jane M.
A1  - Trauth, Martin H.
T1  - Palaeolimnological reconstruction of recent environmental change in Lake Malombe (S. Malawi) using multiple proxies
JF  - Water SA
N2  - Shallow inland water bodies in Malawi continue to be threatened by various environmental challenges despite their importance to the fisheries industry. Due to the complex interaction between natural and anthropogenic disturbances, disentangling the effect of the two may be a complicated process. The littoral zone of most water bodies is important in environmental reconstructions including pollution and lake level monitoring. This study used a littoral zone, transect-based approach employing multi-proxy palaeolimnological techniques to reconstruct recent environmental change (ca. 100 yrs.) in Lake Malombe in the Malawi Rift, East Africa. The results of the study could inform fisheries management in Lake Malombe, which experienced a catastrophic decline in fish stocks. Results support documentary evidence for the complete desiccation of the lake less than 100 years ago. Subsequently, there is evidence for accelerated eutrophication in the recent past. In light of these results, it is concluded that transect sampling approaches rather than relying on single core measurements, and the need for careful consideration of the types of proxy, are significant considerations in palaeoenvironmental reconstructions.
KW  - littoral zone
KW  - palaeolimnology
KW  - diatoms
KW  - Lake Malombe
Y1  - 2014
U6  - https://doi.org/10.4314/wsa.v40i4.17
SN  - 0378-4738
SN  - 1816-7950
VL  - 40
IS  - 4
SP  - 717
EP  - 727
PB  - Water Research Commission
CY  - Pretoria
ER  - 
TY  - JOUR
A1  - Crausbay, Shelley
A1  - Genderjahn, Steffi
A1  - Hotchkiss, Sara
A1  - Sachse, Dirk
A1  - Kahmen, Ansgar
A1  - Arndt, Stefan K.
T1  - Vegetation dynamics at the upper reaches of a tropical montane forest are driven by disturbance over the past 7300 years
JF  - Arctic, antarctic, and alpine research : an interdisciplinary journal
N2  - We assessed tropical montane cloud forest (TMCF) sensitivity to natural disturbance by drought, fire, and dieback with a 7300-year-long paleorecord. We analyzed pollen assemblages, charcoal accumulation rates, and higher plant biomarker compounds (average chain length [ACL] of n-alkanes) in sediments from Wai 'anapanapa, a small lake near the upper forest limit and the mean trade wind inversion ('IWI) in Hawai`i. The paleorecord of ACL suggests increased drought frequency and a lower awl elevation from 2555-1323 cal yr B.P. and 606-334 cal yr B.P. Charcoal began to accumulate and a novel fire regime was initiated ca. 880 cal yr B.P., followed by a decreased fire return interval at ca. 550 cal yr B.P. Diebacks occurred at 2931, 2161, 1162, and 306 cal yr B.P., and two of these were independent of drought or fire. Pollen assemblages indicate that on average species composition changed only 2.8% per decade. These dynamics, though slight, were significantly associated with disturbance. The direction of species composition change varied with disturbance type. Drought was associated with significantly more vines and lianas; fire was associated with an increase in the tree fern Sadleria and indicators of open, disturbed landscapes at the expense of epiphytic ferns; whereas stand-scale dieback was associated with an increase in the tree fern Cibotium. Though this cloud forest was dynamic in response to past disturbance, it has recovered, suggesting a resilient TMCF with no evidence of state change in vegetation type (e.g., grassland or shrubland).
Y1  - 2014
U6  - https://doi.org/10.1657/1938-4246-46.4.787
SN  - 1523-0430
SN  - 1938-4246
VL  - 46
IS  - 4
SP  - 787
EP  - 799
PB  - Institute of Arctic and Alpine Research, University of Colorado
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Haßler, Sibylle Kathrin
A1  - Lark, R. M.
A1  - Zimmermann, Beate
A1  - Elsenbeer, Helmut
T1  - Which sampling design to monitor saturated hydraulic conductivity?
JF  - European journal of soil science
N2  - Soil in a changing world is subject to both anthropogenic and environmental stresses. Soil monitoring is essential to assess the magnitude of changes in soil variables and how they affect ecosystem processes and human livelihoods. However, we cannot always be sure which sampling design is best for a given monitoring task. We employed a rotational stratified simple random sampling (rotStRS) for the estimation of temporal changes in the spatial mean of saturated hydraulic conductivity (K-s) at three sites in central Panama in 2009, 2010 and 2011. To assess this design's efficiency we compared the resulting estimates of the spatial mean and variance for 2009 with those gained from stratified simple random sampling (StRS), which was effectively the data obtained on the first sampling time, and with an equivalent unexecuted simple random sampling (SRS). The poor performance of geometrical stratification and the weak predictive relationship between measurements of successive years yielded no advantage of sampling designs more complex than SRS. The failure of stratification may be attributed to the small large-scale variability of K-s. Revisiting previously sampled locations was not beneficial because of the large small-scale variability in combination with destructive sampling, resulting in poor consistency between revisited samples. We conclude that for our K-s monitoring scheme, repeated SRS is equally effective as rotStRS. Some problems of small-scale variability might be overcome by collecting several samples at close range to reduce the effect of small-scale variation. Finally, we give recommendations on the key factors to consider when deciding whether to use stratification and rotation in a soil monitoring scheme.
Y1  - 2014
U6  - https://doi.org/10.1111/ejss.12174
SN  - 1351-0754
SN  - 1365-2389
VL  - 65
IS  - 6
SP  - 792
EP  - 802
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Hunziker, Matthias
A1  - Sigurdsson, Bjarni D.
A1  - Halldorsson, Gudmundur
A1  - Schwanghart, Wolfgang
A1  - Kuhn, Nikolaus
T1  - Biomass allometries and coarse root biomass distribution of mountain birch in southern Iceland
JF  - Icelandic agricultural sciences
N2  - Root systems are an important pool of biomass and carbon in forest ecosystems. However, most allometric studies on forest trees focus only on the aboveground components. When estimated, root biomass has most often been calculated by using a fixed conversion factor from aboveground biomass. In order to study the size-related development of the root system of native mountain birch (Betula pubescens Ehrh. ssp. czerepanovii), we collected the coarse root system of 25 different aged birch trees (stem diameter at 50 cm length between 0.2 and 14.1 cm) and characterized them by penetration depth (< 1 m) and root thickness. Based on this dataset, allometric functions for coarse roots (> 5 mm and > 2 mm), root stock, total belowground biomass and aboveground biomass components were calculated by a nonlinear and a linear fitting approach. The study showed that coarse root biomass of mountain birch was almost exclusively (> 95 weight-%) located in the top 30 cm, even in a natural old-growth woodland. By using a cross-validation approach, we found that the nonlinear fitting procedure performed better than the linear approach with respect to predictive power. In addition, our results underscore that general assumptions of fixed conversion factors lead to an underestimation of the belowground biomass. Thus, our results provide allometric functions for a more accurate root biomass estimation to be utilized in inventory reports and ecological studies.
KW  - mountain birch
KW  - belowground biomass
KW  - root depth distribution
KW  - aboveground biomass
KW  - Betula pubescens Ehrh. ssp czerepanovii
Y1  - 2014
SN  - 1670-567X
VL  - 27
SP  - 111
EP  - 125
PB  - Agricultural University of Iceland
CY  - Reykjavik
ER  - 
TY  - JOUR
A1  - Li, Shaoyang
A1  - Moreno, Marcos
A1  - Rosenau, Matthias
A1  - Melnick, Daniel
A1  - Oncken, Onno
T1  - Splay fault triggering by great subduction earthquakes inferred from finite element models
JF  - Geophysical research letters
N2  - We have investigated the influence that megathrust earthquake slip has on the activation of splay faults using a 2-D finite element method (FEM), taking into account the effects of gravity and variations in the frictional strength properties of splay faults. We simulated both landward-dipping and seaward-dipping splay fault geometries, and imposed depth-variable slip distributions of subduction events. Our results indicate that the two types of splay fault exhibit a similar behavior, with variations in frictional properties along the faults affecting only the seismic magnitude. The triggering process is controlled by a critical depth. Megathrust slip concentrated at depths shallower than the critical depth will favor normal displacement, while megathrust slip concentrated at depths deeper than the critical depth is likely to result in reverse motion. Our results thus provide a useful tool for predicting the activation of secondary faults and may have direct implications for tsunami hazard research.
KW  - earthquake deformation
KW  - subduction zone earthquakes
KW  - splay faults
KW  - faulting behavior
KW  - FEM models
KW  - tsunami hazards
Y1  - 2014
U6  - https://doi.org/10.1002/2013GL058598
SN  - 0094-8276
SN  - 1944-8007
VL  - 41
IS  - 2
SP  - 385
EP  - 391
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schwanghart, Wolfgang
A1  - Scherler, Dirk
T1  - Short Communication: TopoToolbox 2-MATLAB-based software for topographic analysis and modeling in Earth surface sciences
JF  - Earth surface dynamics
N2  - TopoToolbox is a MATLAB program for the analysis of digital elevation models (DEMs). With the release of version 2, the software adopts an object-oriented programming (OOP) approach to work with gridded DEMs and derived data such as flow directions and stream networks. The introduction of a novel technique to store flow directions as topologically ordered vectors of indices enables calculation of flow-related attributes such as flow accumulation similar to 20 times faster than conventional algorithms while at the same time reducing memory overhead to 33% of that required by the previous version. Graphical user interfaces (GUIs) enable visual exploration and interaction with DEMs and derivatives and provide access to tools targeted at fluvial and tectonic geomorphologists. With its new release, TopoToolbox has become a more memory-efficient and faster tool for basic and advanced digital terrain analysis that can be used as a framework for building hydrological and geomorphological models in MATLAB.
Y1  - 2014
U6  - https://doi.org/10.5194/esurf-2-1-2014
SN  - 2196-6311
SN  - 2196-632X
VL  - 2
IS  - 1
SP  - 1
EP  - 7
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Reiter, Karsten
A1  - Heidbach, Oliver
T1  - 3-D geomechanical-numerical model of the contemporary crustal stress state in the Alberta Basin (Canada)
JF  - Solid earth
N2  - In the context of examining the potential usage of safe and sustainable geothermal energy in the Alberta Basin, whether in deep sediments or crystalline rock, the understanding of the in situ stress state is crucial. It is a key challenge to estimate the 3-D stress state at an arbitrarily chosen point in the crust, based on sparsely distributed in situ stress data.
 To address this challenge, we present a large-scale 3-D geomechanical-numerical model (700 km x 1200 km x 80 km) from a large portion of the Alberta Basin, to provide a 3-D continuous quantification of the contemporary stress orientations and stress magnitudes. To calibrate the model, we use a large database of in situ stress orientation (321 S-Hmax) as well as stress magnitude data (981 S-V, 1720 S-hmin and 2 (+11) S-Hmax) from the Alberta Basin. To find the best-fit model, we vary the material properties and primarily the displacement boundary conditions of the model. This study focusses in detail on the statistical calibration procedure, because of the large amount of available data, the diversity of data types, and the importance of the order of data tests.
 The best-fit model provides the total 3-D stress tensor for nearly the whole Alberta Basin, and allows estimation of stress orientation and stress magnitudes in advance of any well. First-order implications for the well design and configuration of enhanced geothermal systems are revealed. Systematic deviations of the modelled stress from the in situ data are found for stress orientations in the Peace River and the Bow Island Arch as well as for leak-off test magnitudes.
Y1  - 2014
U6  - https://doi.org/10.5194/se-5-1123-2014
SN  - 1869-9510
SN  - 1869-9529
VL  - 5
IS  - 2
SP  - 1123
EP  - 1149
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Reiter, Karsten
A1  - Heidbach, Oliver
A1  - Schmitt, Douglas
A1  - Haug, Kristine
A1  - Ziegler, Moritz O.
A1  - Moeck, Inga
T1  - A revised crustal stress orientation database for Canada
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - The Canadian database on contemporary crustal stress has not been revised systematically in the past two decades. Here we present the results of our new compilation that contains 514 new data records for the orientation data of maximum compressive horizontal stress and 188 data records that were re-assessed. In total the Canadian stress database has now 1667 data records, which is an increase of about 45%. From these data, a new Canadian Stress map as well as one for the Province of Alberta is presented.
 To analyse the stress pattern, we use the quasi median on the circle as a smoothing algorithm that generates a smoothed stress map of the maximum compressive horizontal stress orientation on a regular grid. The newly introduced quasi interquartile range on the circle estimates the spreading of the data and is used as a measure for the wave-length of the stress pattern. The result of the hybrid wavelength analysis confirms that long spatial wavelength stress patterns (>= 1000 km) exist in large areas in Canada. The observed stress pattern is transmitted through the intra-plate regions.
 The results reveal that shorter spatial wave length variation of the maximum compressive horizontal stress orientation of less than 200 km, prevails particularly in south-eastern and western Canada. Regional stress sources such as density contrasts, active fault systems, crustal structures, etc. might have a significant impact in these regions. In contrast to these variations, the observed stress pattern in the Alberta Basin is very homogeneous and mainly controlled by plate boundary forces and body forces. The influence of curvature of the Rocky Mountains salient in southern Alberta is minimal. The present-day horizontal stress orientations determined herein have important implications for the production of hydrocarbons and geothermal energy in the Alberta Basin. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Stress pattern
KW  - Tectonic stress
KW  - Canada
KW  - Alberta
KW  - Database
KW  - Circular statistics
Y1  - 2014
U6  - https://doi.org/10.1016/j.tecto.2014.08.006
SN  - 0040-1951
SN  - 1879-3266
VL  - 636
SP  - 111
EP  - 124
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Vales, Dina
A1  - Dias, Nuno A.
A1  - Rio, Ines
A1  - Matias, Luis
A1  - Silveira, Graca
A1  - Madeira, Jose
A1  - Weber, Michael H.
A1  - Carrilho, Fernando
A1  - Haberland, Christian
T1  - Intraplate seismicity across the Cape Verde swell: A contribution from a temporary seismic network
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - We present an analysis and characterization of the regional seismicity recorded by a temporary broadband seismic network deployed in the Cape Verde archipelago between November 2007 and September 2008.
 The detection of earthquakes was based on spectrograms, allowing the discrimination from low-frequency volcanic signals, resulting in 358 events of which 265 were located, the magnitudes usually being smaller than 3. For the location, a new 1-D P-velocity model was derived for the region showing a crust consistent with an oceanic crustal structure. The seismicity is located mostly offshore the westernmost and geologically youngest areas of the archipelago, near the islands of Santo Antao and Sao Vicente in the NW and Brava and Fogo in the SW. The SW cluster has a lower occurrence rate and corresponds to seismicity concentrated mainly along an alignment between Brava and the Cadamosto seamount presenting normal faulting mechanisms. The existence of the NW cluster, located offshore SW of Santo Antao, was so far unknown and concentrates around a recently recognized submarine cone field; this cluster presents focal depths extending from the crust to the upper mantle and suggests volcanic unrest No evident temporal behaviour could be perceived, although the events tend to occur in bursts of activity lasting a few days. In this recording period, no significant activity was detected at Fogo volcano, the most active volcanic edifice in Cape Verde.
 The seismicity characteristics point mainly to a volcanic origin. The correlation of the recorded seismicity with active volcanic structures agrees with the tendency for a westward migration of volcanic activity in the archipelago as indicated by the geologic record. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Intraplate seismicity
KW  - Clustering
KW  - Local magnitude scale
KW  - Active volcanism
KW  - Cape Verde
KW  - Atlantic Ocean
Y1  - 2014
U6  - https://doi.org/10.1016/j.tecto.2014.09.014
SN  - 0040-1951
SN  - 1879-3266
VL  - 636
SP  - 325
EP  - 337
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Pourteau, Amaury
A1  - Bousquet, Romain
A1  - Vidal, Olivier
A1  - Plunder, Alexis
A1  - Duesterhoeft, Erik
A1  - Candan, Osman
A1  - Oberhänsli, Roland
T1  - Multistage growth of Fe-Mg-carpholite and Fe-Mg-chloritoid, from field evidence to thermodynamic modelling
JF  - Contributions to mineralogy and petrology
N2  - We provide new insights into the prograde evolution of HP/LT metasedimentary rocks on the basis of detailed petrologic examination, element-partitioning analysis, and thermodynamic modelling of well-preserved Fe-Mg-carpholite- and Fe-Mg-chloritoid-bearing rocks from the Afyon Zone (Anatolia). We document continuous and discontinuous compositional (ferromagnesian substitution) zoning of carpholite (overall X-Mg = 0.27-0.73) and chloritoid (overall X-Mg = 0.07-0.30), as well as clear equilibrium and disequilibrium (i.e., reaction-related) textures involving carpholite and chloritoid, which consistently account for the consistent enrichment in Mg of both minerals through time, and the progressive replacement of carpholite by chloritoid. Mg/Fe distribution coefficients calculated between carpholite and chloritoid vary widely within samples (2.2-20.0). Among this range, only values of 7-11 correlate with equilibrium textures, in agreement with data from the literature. Equilibrium phase diagrams for metapelitic compositions are calculated using a newly modified thermodynamic dataset, including most recent data for carpholite, chloritoid, chlorite, and white mica, as well as further refinements for Fe-carpholite, and both chloritoid end-members, as required to reproduce accurately petrologic observations (phase relations, experimental constraints, Mg/Fe partitioning). Modelling reveals that Mg/Fe partitioning between carpholite and chloritoid is greatly sensitive to temperature and calls for a future evaluation of possible use as a thermometer. In addition, calculations show significant effective bulk composition changes during prograde metamorphism due to the fractionation of chloritoid formed at the expense of carpholite. We retrieve P-T conditions for several carpholite and chloritoid growth stages (1) during prograde stages using unfractionated, bulk-rock XRF analyses, and (2) at peak conditions using compositions fractionated for chloritoid. The P-T paths reconstructed for the Kutahya and Afyon areas shed light on contrasting temperature conditions for these areas during prograde and peak stages.
KW  - HP/LT metamorphism
KW  - Carpholite
KW  - Chloritoid
KW  - Growth zoning
KW  - Element partitioning
KW  - Chemical fractionation
Y1  - 2014
U6  - https://doi.org/10.1007/s00410-014-1090-7
SN  - 0010-7999
SN  - 1432-0967
VL  - 168
IS  - 6
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Wang, Ping
A1  - Scherler, Dirk
A1  - Jing Liu-Zeng, 
A1  - Mey, Jürgen
A1  - Avouac, Jean-Philippe
A1  - Zhang, Yunda
A1  - Shi, Dingguo
T1  - Tectonic control of Yarlung Tsangpo Gorge revealed by a buried canyon in Southern Tibet
JF  - Science
N2  - The Himalayan mountains are dissected by some of the deepest and most impressive gorges on Earth. Constraining the interplay between river incision and rock uplift is important for understanding tectonic deformation in this region. We report here the discovery of a deeply incised canyon of the Yarlung Tsangpo River, at the eastern end of the Himalaya, which is now buried under more than 500 meters of sediments. By reconstructing the former valley bottom and dating sediments at the base of the valley fill, we show that steepening of the Tsangpo Gorge started at about 2 million to 2.5 million years ago as a consequence of an increase in rock uplift rates. The high erosion rates within the gorge are therefore a direct consequence of rapid rock uplift.
Y1  - 2014
U6  - https://doi.org/10.1126/science.1259041
SN  - 0036-8075
SN  - 1095-9203
VL  - 346
IS  - 6212
SP  - 978
EP  - 981
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Noah, Mareike
A1  - Lappe, Michael
A1  - Schneider, Beate
A1  - Vieth-Hillebrand, Andrea
A1  - Wilkes, Heinz
A1  - Kallmeyer, Jens
T1  - Tracing biogeochemical and microbial variability over a complete oil sand mining and recultivation process
JF  - The science of the total environment : an international journal for scientific research into the environment and its relationship with man
N2  - Recultivation of disturbed oil sand mining areas is an issue of increasing importance. Nevertheless only little is known about the fate of organic matter, cell abundances and microbial community structures during oil sand processing, tailings management and initial soil development on reclamation sites. Thus the focus of this work is on biogeochemical changes of mined oil sands through the entire process chain until its use as substratum for newly developing soils on reclamation sites. Therefore, oil sand, mature fine tailings (MFTs) from tailings ponds and drying cells and tailings sand covered with peat-mineral mix (PMM) as part of land reclamation were analyzed. The sample set was selected to address the question whether changes in the above-mentioned biogeochemical parameters can be related to oil sand processing or biological processes and how these changes influence microbial activities and soil development.
 GC-MS analyses of oil-derived biomarkers reveal that these compounds remain unaffected by oil sand processing and biological activity. In contrast, changes in polycyclic aromatic hydrocarbon (PAH) abundance and pattern can be observed along the process chain. Especially naphthalenes, phenanthrenes and chrysenes are altered or absent on reclamation sites, Furthermore, root-bearing horizons on reclamation sites exhibit cell abundances at least ten times higher (10(8) to 10(9) cells g(-1)) than in oil sand and MFF samples (10(7) cells g(-1)) and show a higher diversity in their microbial community structure. Nitrate in the pore water and roots derived from the PMM seem to be the most important stimulants for microbial growth. The combined data show that the observed compositional changes are mostly related to biological activity and the addition of exogenous organic components (PMM), whereas oil extraction, tailings dewatering and compaction do not have significant influences on the evaluated compounds. Microbial community composition remains relatively stable through the entire process chain. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Oil sands
KW  - Tailings ponds
KW  - Reclamation
KW  - PAN
KW  - Biomarker
KW  - Microbial community analysis
Y1  - 2014
U6  - https://doi.org/10.1016/j.scitotenv.2014.08.020
SN  - 0048-9697
SN  - 1879-1026
VL  - 499
SP  - 297
EP  - 310
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mishrat, Praveen K.
A1  - Anoop, A.
A1  - Jehangir, A.
A1  - Prasad, Sushma
A1  - Menze, R.
A1  - Schettler, Georg
A1  - Naumann, R.
A1  - Weise, S.
A1  - Andersen, N.
A1  - Yousuf, A. R.
A1  - Gaye, Birgit
T1  - Limnology and modern sedimentation patterns in high altitude Tso Moriri Lake, NW Himalaya - implications for proxy development
JF  - Fundamental and applied limnology : official journal of the International Association of Theoretical and Applied Limnology
N2  - We report the results of our investigations on the catchment area, lake surface sediments, and hydrology of the high altitude alpine Tso Moriri Lake, NW Himalayas (India). Our results indicate that the lake is currently alkaline, and thermally stratified with an oxic bottom layer. Results from hydrochemistry and isotopic composition (delta O-18 and delta D) of inflowing streams and lake waters show that Tso Moriri Lake is an evaporative lake with contributions from both westerly source (snow melt) and Indian summer monsoon precipitation. Geochemical and mineralogical investigations on the catchment and lake surface sediments reveal the presence of authigenic aragonite in modern lake sediment. The lithogenic components reflect the inflow and sorting processes during transport into the lake, whereas the authigenic carbonate fraction can be linked to the changes in ([precipitation+meltwater]/evaporation) (I/E) balance within the lake. The spatial variability in grain size distribution within the lake surface sediments shows that the grain size data can be utilised as a proxy for transport energy and shoreline proximity in the lake basin. We have evaluated the applicability of commonly applied environmentally sensitive proxies (isotopes, mineralogy, weathering indices) for palaeoenvironmental reconstruction in the Tso Moriri Lake. Our results show that the commonly used weathering index (Rb/Sr) is not applicable due to Sr contribution from authigenic carbonates. The useful weathering indices in Tso Moriri Lake are the Si/Al and the Chemical Proxy of Alteration (CPA). Since the carbonates are formed by evaporative processes, their presence and isotopic values can be used as indicators of I/E changes in the lake.
KW  - geochemistry
KW  - lake sediments
KW  - palaeoenvironmental proxies
KW  - Tso Moriri Lake
KW  - weathering indices
Y1  - 2014
U6  - https://doi.org/10.1127/fal/2014/0664
SN  - 1863-9135
VL  - 185
IS  - 3-4
SP  - 329
EP  - 348
PB  - Schweizerbart
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Craddock, William H.
A1  - Kirby, Eric
A1  - Zhang, Huiping
A1  - Clark, Marin K.
A1  - Champagnac, Jean-Daniel
A1  - Yuan, Daoyang
T1  - Rates and style of Cenozoic deformation around the Gonghe Basin, northeastern Tibetan Plateau
JF  - Geosphere
N2  - The northeastern Tibetan Plateau constitutes a transitional region between the low-relief physiographic plateau to the south and the high-relief ranges of the Qilian Shan to the north. Cenozoic deformation across this margin of the plateau is associated with localized growth of fault-cored mountain ranges and associated basins. Herein, we combine detailed structural analysis of the geometry of range-bounding faults and deformation of foreland basin strata with geomorphic and exhumational records of erosion in hangingwall ranges in order to investigate the magnitude, timing, and style of deformation along the two primary fault systems, the Qinghai Nan Shan and the Gonghe Nan Shan. Structural mapping shows that both ranges have developed above imbricate fans of listric thrust faults, which sole into decollements in the middle crust. Restoration of shortening along balanced cross sections suggests a minimum of 0.8-2.2 km and 5.1-6.9 km of shortening, respectively. Growth strata in the associated foreland basin record the onset of deformation on the two fault systems at ca. 6-10 Ma and ca. 7-10 Ma, respectively, and thus our analysis suggests late Cenozoic shortening rates of 0.2 +0.2/-0.1 km/m.y. and 0.7 +0.3/-0.2 km/m.y. along the north and south sides of Gonghe Basin. Along the Qinghai Nan Shan, these rates are similar to late Pleistocene slip rates of similar to 0.10 +/- 0.04 mm/yr, derived from restoration and dating of a deformed alluvial-fan surface. Collectively, our results imply that deformation along both flanks of the doubly vergent Qilian Shan-Nan Shan initiated by ca. 10 Ma and that subsequent shortening has been relatively steady since that time.
Y1  - 2014
U6  - https://doi.org/10.1130/GES01024.1
SN  - 1553-040X
VL  - 10
IS  - 6
SP  - 1255
EP  - 1282
PB  - Geological Society of America
CY  - Boulder
ER  - 
TY  - INPR
A1  - Rehman, Hafiz Ur
A1  - Tsujimori, Tatsuki
A1  - Okamoto, Kazuaki
A1  - Spengler, Dirk
T1  - Petrogenesis and chemogenesis of oceanic and continental orogens in Asia: Current topics, Part I Preface
T2  - The island arc
Y1  - 2014
U6  - https://doi.org/10.1111/iar.12097
SN  - 1038-4871
SN  - 1440-1738
VL  - 23
IS  - 4
SP  - 251
EP  - 253
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Böttcher, Steven
A1  - Merz, Christoph
A1  - Lischeid, Gunnar
A1  - Dannowski, Ralf
T1  - Using Isomap to differentiate between anthropogenic and natural effects on groundwater dynamics in a complex geological setting
JF  - Journal of hydrology
N2  - Due to increasing demands and competition for high quality groundwater resources in many parts of the world, there is an urgent need for efficient methods that shed light on the interplay between complex natural settings and anthropogenic impacts. Thus a new approach is introduced, that aims to identify and quantify the predominant processes or factors of influence that drive groundwater and lake water dynamics on a catchment scale. The approach involves a non-linear dimension reduction method called Isometric feature mapping (Isomap). This method is applied to time series of groundwater head and lake water level data from a complex geological setting in Northeastern Germany. Two factors explaining more than 95% of the observed spatial variations are identified: (1) the anthropogenic impact of a waterworks in the study area and (2) natural groundwater recharge with different degrees of dampening at the respective sites of observation. The approach enables a presumption-free assessment to be made of the existing geological conception in the catchment, leading to an extension of the conception. Previously unknown hydraulic connections between two aquifers are identified, and connections revealed between surface water bodies and groundwater. (C) 2014 Elsevier B.V. All rights reserved.
KW  - Groundwater
KW  - Lake
KW  - Interaction
KW  - Isometric feature mapping
KW  - Time series analysis
Y1  - 2014
U6  - https://doi.org/10.1016/j.jhydrol.2014.09.048
SN  - 0022-1694
SN  - 1879-2707
VL  - 519
SP  - 1634
EP  - 1641
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Ferrero, Silvio
A1  - Braga, R.
A1  - Berkesi, M.
A1  - Cesare, Bernardo
A1  - Ouazaa, N. Laridhi
T1  - Production of metaluminous melt during fluid-present anatexis: an example from the Maghrebian basement, La Galite Archipelago, central Mediterranean
JF  - Journal of metamorphic geology
N2  - Garnet brought to the surface by late Miocene granitoids at La Galite Archipelago (Central Mediterranean, Tunisia) contains abundant primary melt and fluid inclusions. Microstructural observations and mineral chemistry define the host garnet as a peritectic phase produced by biotite incongruent melting at ~800 degrees C and 0.5GPa, under fluid-present conditions. The trapped melt is leucogranitic with an unexpected metaluminous and almost peralkaline character. Fluid inclusions are one phase at room temperature, and contain a CO2-dominated fluid, with minor H2O, N-2 and CH4. Siderite and an OH-bearing phase were identified by Raman and IR spectroscopy within every analysed inclusion, and are interpreted as products of a post-entrapment carbonation/hydration reaction between the fluid and the host during cooling. The fluid present during anatexis is therefore inferred to have been originally richer in both H2O and CO2. The production of anatectic melt with a metaluminous signature can be explained as the result of partial melting of relatively Al-poor protoliths assisted by CO2-rich fluids.
KW  - fluid inclusions
KW  - garnet
KW  - anatexis
KW  - nanogranites
KW  - melt inclusions
Y1  - 2014
U6  - https://doi.org/10.1111/jmg.12068
SN  - 0263-4929
SN  - 1525-1314
VL  - 32
IS  - 2
SP  - 209
EP  - 225
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Deplazes, Gaudenz
A1  - Lückge, Andreas
A1  - Stuut, Jan-Berend W.
A1  - Paetzold, Jürgen
A1  - Kuhlmann, Holger
A1  - Husson, Dorothee
A1  - Fant, Mara
A1  - Haug, Gerald H.
T1  - Weakening and strengthening of the Indian monsoon during Heinrich events and Dansgaard- Oeschger oscillations
JF  - Paleoceanography
N2  - The Dansgaard-Oeschger oscillations and Heinrich events described in North Atlantic sediments and Greenland ice are expressed in the climate of the tropics, for example, as documented in Arabian Sea sediments. Given the strength of this teleconnection, we seek to reconstruct its range of environmental impacts. We present geochemical and sedimentological data from core SO130-289KL from the Indus submarine slope spanning the last similar to 80 kyr. Elemental and grain size analyses consistently indicate that interstadials are characterized by an increased contribution of fluvial suspension from the Indus River. In contrast, stadials are characterized by an increased contribution of aeolian dust from the Arabian Peninsula. Decadal-scale shifts at climate transitions, such as onsets of interstadials, were coeval with changes in productivity-related proxies. Heinrich events stand out as especially dry and dusty events, indicating a dramatically weakened Indian summer monsoon, potentially increased winter monsoon circulation, and increased aridity on the Arabian Peninsula. This finding is consistent with other paleoclimate evidence for continental aridity in the northern tropics during these events. Our results strengthen the evidence that circum-North Atlantic temperature variations translate to hydrological shifts in the tropics, with major impacts on regional environmental conditions such as rainfall, river discharge, aeolian dust transport, and ocean margin anoxia.
KW  - Indian Monsoon
KW  - Arabian Sea
KW  - XRF
KW  - Dansgaard-Oeschger oscillations
KW  - Heinrich events
KW  - Sediment Transport
Y1  - 2014
U6  - https://doi.org/10.1002/2013PA002509
SN  - 0883-8305
SN  - 1944-9186
VL  - 29
IS  - 2
SP  - 99
EP  - 114
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Hermkes, Marcel
A1  - Kühn, Nicolas M.
A1  - Riggelsen, Carsten
T1  - Simultaneous quantification of epistemic and aleatory uncertainty in GMPEs using Gaussian process regression
JF  - Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering
N2  - This paper presents a Bayesian non-parametric method based on Gaussian Process (GP) regression to derive ground-motion models for peak-ground parameters and response spectral ordinates. Due to its non-parametric nature there is no need to specify any fixed functional form as in parametric regression models. A GP defines a distribution over functions, which implicitly expresses the uncertainty over the underlying data generating process. An advantage of GP regression is that it is possible to capture the whole uncertainty involved in ground-motion modeling, both in terms of aleatory variability as well as epistemic uncertainty associated with the underlying functional form and data coverage. The distribution over functions is updated in a Bayesian way by computing the posterior distribution of the GP after observing ground-motion data, which in turn can be used to make predictions. The proposed GP regression models is evaluated on a subset of the RESORCE data base for the SIGMA project. The experiments show that GP models have a better generalization error than a simple parametric regression model. A visual assessment of different scenarios demonstrates that the inferred GP models are physically plausible.
KW  - Gaussian Process regression
KW  - Epistemic uncertainty
KW  - Aleatory variability
KW  - Empirical ground-motion models
KW  - Bayesian non-parametrics
KW  - GMPE
KW  - Generalization error
Y1  - 2014
U6  - https://doi.org/10.1007/s10518-013-9507-7
SN  - 1570-761X
SN  - 1573-1456
VL  - 12
IS  - 1
SP  - 449
EP  - 466
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Serno, Sascha
A1  - Winckler, Gisela
A1  - Anderson, Robert F.
A1  - Hayes, Christopher T.
A1  - McGee, David
A1  - Machalett, Bjoern
A1  - Ren, Haojia
A1  - Straub, Susanne M.
A1  - Gersonde, Rainer
A1  - Haug, Gerald H.
T1  - Eolian dust input to the Subarctic North Pacific
JF  - Earth & planetary science letters
N2  - Eolian dust is a significant source of iron and other nutrients that are essential for the health of marine ecosystems and potentially a controlling factor of the high nutrient-low chlorophyll status of the Subarctic North Pacific. We map the spatial distribution of dust input using three different geochemical tracers of eolian dust, He-4, Th-232 and rare earth elements, in combination with grain size distribution data, from a set of core-top sediments covering the entire Subarctic North Pacific. Using the suite of geochemical proxies to fingerprint different lithogenic components, we deconvolve eolian dust input from other lithogenic inputs such as volcanic ash, ice-rafted debris, riverine and hemipelagic input. While the open ocean sites far away from the volcanic arcs are dominantly composed of pure eolian dust, lithogenic components other than eolian dust play a more crucial role along the arcs. In sites dominated by dust, eolian dust input appears to be characterized by a nearly uniform grain size mode at similar to 4 mu m.
 Applying the Th-230-normalization technique, our proxies yield a consistent pattern of uniform dust fluxes of 1-2 g/m(2)/yr across the Subarctic North Pacific. Elevated eolian dust fluxes of 2-4 g/m(2)/yr characterize the westernmost region off Japan and the southern Kurile Islands south of 45 degrees N and west of 165 degrees E along the main pathway of the westerly winds. The core-top based dust flux reconstruction is consistent with recent estimates based on dissolved thorium isotope concentrations in seawater from the Subarctic North Pacific. The dust flux pattern compares well with state-of-the-art dust model predictions in the western and central Subarctic North Pacific, but we find that dust fluxes are higher than modeled fluxes by 0.5-1 g/m(2)/yr in the northwest, northeast and eastern Subarctic North Pacific. Our results provide an important benchmark for biogeochemical models and a robust approach for downcore studies testing dust-induced iron fertilization of past changes in biological productivity in the Subarctic North Pacific.
KW  - eolian dust
KW  - Subarctic North Pacific
KW  - INOPEX
KW  - helium-4
KW  - Th-232
KW  - REE
Y1  - 2014
U6  - https://doi.org/10.1016/j.epsl.2013.11.008
SN  - 0012-821X
SN  - 1385-013X
VL  - 387
SP  - 252
EP  - 263
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Rach, Oliver
A1  - Brauer, Achim
A1  - Wilkes, Heinz
A1  - Sachse, Dirk
T1  - Delayed hydrological response to Greenland cooling at the onset of the Younger Dryas in western Europe
JF  - Nature geoscience
N2  - The general warming trend of the last deglaciation was interrupted by the Younger Dryas, a period of abrupt cooling and widespread environmental change(1-10). Ice core records suggest the abrupt cooling began 12,846 years ago in Greenland(10), about 170 years before the significant environmental and vegetation change in western Europe(7) classically defined as the Younger Dryas. However, this difference in timing falls within age model uncertainties. Here we use the hydrogen isotope composition of lipid biomarkers from precisely dated varved sediments from Lake Meerfelder Maar to reconstruct hydroclimate over western Europe. We observe a decrease in the hydrogen isotope values of both aquatic and terrestrial lipids 12,850 years ago, indicating cooling climate in this region synchronous with the abrupt cooling in Greenland. A second drop occurs 170 years later, mainly in the hydrogen isotope record of aquatic lipids but to a lesser extent in the terrestrial lipids, which we attribute to aridification, as well as a change in moisture source and pathway. We thus confirm that there was indeed a lag between cooling and substantial hydrologic and environmental change in western Europe. We suggest the delay is related to the expansion of sea ice in the North Atlantic Ocean and the subsequent southward migration of the westerly wind system(9). We further suggest that these hydrological changes amplified environmental change in western Europe at the onset of the Younger Dryas.
Y1  - 2014
U6  - https://doi.org/10.1038/NGEO2053
SN  - 1752-0894
SN  - 1752-0908
VL  - 7
IS  - 2
SP  - 109
EP  - 112
PB  - Nature Publ. Group
CY  - New York
ER  -