TY  - JOUR
A1  - Zuhr, Alexandra M.
A1  - Dolman, Andrew M.
A1  - Ho, Sze Ling
A1  - Groeneveld, Jeroen
A1  - Loewemark, Ludvig
A1  - Grotheer, Hendrik
A1  - Su, Chih-Chieh
A1  - Laepple, Thomas
T1  - Age-heterogeneity in marine sediments revealed by three-dimensional high-resolution radiocarbon measurements
JF  - Frontiers in Earth Science
N2  - Marine sedimentary archives are routinely used to reconstruct past environmental changes. In many cases, bioturbation and sedimentary mixing affect the proxy time-series and the age-depth relationship. While idealized models of bioturbation exist, they usually assume homogeneous mixing, thus that a single sample is representative for the sediment layer it is sampled from. 

However, it is largely unknown to which extent this assumption holds for sediments used for paleoclimate reconstructions. 
To shed light on 
1) the age-depth relationship and its full uncertainty, 
2) the magnitude of mixing processes affecting the downcore proxy variations, and 
3) the representativity of the discrete sample for the sediment layer, we designed and performed a case study on South China Sea sediment material which was collected using a box corer and which covers the last glacial cycle. 

Using the radiocarbon content of foraminiferal tests as a tracer of time, we characterize the spatial age-heterogeneity of sediments in a three-dimensional setup. In total, 118 radiocarbon measurements were performed on defined small- and large-volume bulk samples ( similar to 200 specimens each) to investigate the horizontal heterogeneity of the sediment. Additionally, replicated measurements on small numbers of specimens (10 x 5 specimens) were performed to assess the heterogeneity within a sample volume. Visual assessment of X-ray images and a quantitative assessment of the mixing strength show typical mixing from bioturbation corresponding to around 10 cm mixing depth. 

Notably, our 3D radiocarbon distribution reveals that the horizontal heterogeneity (up to 1,250 years), contributing to the age uncertainty, is several times larger than the typically assumed radiocarbon based age-model error (single errors up to 250 years). Furthermore, the assumption of a perfectly bioturbated layer with no mixing underneath is not met. 

Our analysis further demonstrates that the age-heterogeneity might be a function of sample size; smaller samples might contain single features from the incomplete mixing and are thus less representative than larger samples. 
We provide suggestions for future studies, optimal sampling strategies for quantitative paleoclimate reconstructions and realistic uncertainty in age models, as well as discuss possible implications for the interpretation of paleoclimate records.
KW  - paleoceanography
KW  - radiocarbon
KW  - age-heterogeneity
KW  - marine sediments
KW  - planktonic foraminifera
KW  - bioturbation
KW  - agemodeling
KW  - South China Sea
Y1  - 2022
U6  - https://doi.org/10.3389/feart.2022.871902
SN  - 2296-6463
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Zhang, Di
A1  - Cao, Kai
A1  - Yuan, Xiaoping
A1  - Wang, Guocan
A1  - van der Beek, Peter
T1  - Late Oligocene-early Miocene origin of the First Bend of the Yangtze River explained by thrusting-induced river reorganization
JF  - Geomorphology
N2  - The origin of the First Bend of the Yangtze River is key to understanding the birth of the modern Yangtze River. Despite considerable efforts, the timing and mechanism of formation of the First Bend remain highly debated. Inverse river-profile modeling of three tributaries (Chongjiang, Lima, and Gudu) of the Jinsha River, integrated with regional tectonic and geomorphic interpretations, allows the onset of incision at the First Bend to be constrained to 28-20 Ma. The spatio-temporal coincidence of initial river incision and activity of Yulong Thrust Belt in southeastern Tibet highlights thrusting to be fundamental in reshaping the pre-existing stream network at the First Bend. These results enable us to reinterpret a change in sedimentary environment from a braided river to a swamp-like lake in the Jianchuan Basin south of the First Bend, recording the destruction of the hypothesized southwards-flowing paleo-Jinsha and Shuiluo Rivers at ~36-35 Ma by magmatism. During the late Oligoceneearly Miocene, the paleo-Shuiluo River was diverted to the north by focused rock uplift due to thrusting along the Yulong Thrust Belt, which also led to exhumation of the Jianchuan Basin. Diversion of the paleo-Shuiluo River can be explained by capture from a downstream river in the footwall of the Yulong Thrust Belt. Subsequent rapid headward erosion, that was caused by thrusting-induced drop of local base level, is recorded by upstream younging ages for the onset of incision and led to the formation of the First Bend. The combination of new ages for the onset of incision at 28-20 Ma at the First Bend and younger ages upstream indicates northwards expansion of the Jinsha River at a rate of 62 +/- 18 mm/yr. Our results suggest that the origin of the First Bend was likely triggered by thrusting at 28-20 Ma, after which the Yangtze River formed.
KW  - Tibetan Plateau
KW  - Yangtze River
KW  - river incision
KW  - inverse modeling
Y1  - 2022
U6  - https://doi.org/10.1016/j.geomorph.2022.108303
SN  - 0169-555X
SN  - 1872-695X
VL  - 411
PB  - Elsevier Science
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Yuan, Xiaoping P.
A1  - Jiao, Ruohong
A1  - Dupont-Nivet, Guillaume
A1  - Shen, Xiaoming
T1  - Southeastern Tibetan Plateau growth revealed by inverse analysis of landscape evolution model
JF  - Geophysical research letters
N2  - The Cenozoic history of the Tibetan Plateau topography is critical for understanding the evolution of the Indian-Eurasian collision, climate, and biodiversity. However, the long-term growth and landscape evolution of the Tibetan Plateau remain ambiguous, it remains unclear if plateau uplift occurred soon after the India-Asia collision in the Paleogene (similar to 50-25 Ma) or later in the Neogene (similar to 20-5 Ma). Here, we reproduce the uplift history of the southeastern Tibetan Plateau using a 2D landscape evolution model, which simultaneously solves fluvial erosion and sediment transport processes in the drainage basins of the Three Rivers region (Yangtze, Mekong, and Salween Rivers). Our model was optimized through a formal inverse analysis with 20,000 forward simulations, which aims to reconcile the transient states of the present-day river profiles. The results, compared to existing paleoelevation and thermochronologic data, suggest initially low elevations (similar to 300-500 m) during the Paleogene, followed by a gradual southeastward propagation of topographic uplift of the plateau margin.
KW  - Tibetan Plateau
KW  - landscape evolution
KW  - fluvial erosion
KW  - inverse analysis
KW  - mountain growth
KW  - propagating uplift
Y1  - 2022
U6  - https://doi.org/10.1029/2021GL097623
SN  - 0094-8276
SN  - 1944-8007
VL  - 49
IS  - 10
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Yen, Ming-Hsuan
A1  - von Specht, Sebastian
A1  - Lin, Yen-Yu
A1  - Cotton, Fabrice
A1  - Ma, Kuo-Fong
T1  - Within- and between-event variabilities of strong-velocity pulses of moderate earthquakes within dense seismic arrays
JF  - Bulletin of the Seismological Society of America
N2  - Ground motion with strong-velocity pulses can cause significant damage to buildings and structures at certain periods; hence, knowing the period and velocity amplitude of such pulses is critical for earthquake structural engineering. 
However, the physical factors relating the scaling of pulse periods with magnitude are poorly understood. 
In this study, we investigate moderate but damaging earthquakes (M-w 6-7) and characterize ground- motion pulses using the method of Shahi and Baker (2014) while considering the potential static-offset effects. 
We confirm that the within-event variability of the pulses is large. The identified pulses in this study are mostly from strike-slip-like earthquakes. We further perform simulations using the freq uency-wavenumber algorithm to investigate the causes of the variability of the pulse periods within and between events for moderate strike-slip earthquakes. 
We test the effect of fault dips, and the impact of the asperity locations and sizes. The simulations reveal that the asperity properties have a high impact on the pulse periods and amplitudes at nearby stations. 
Our results emphasize the importance of asperity characteristics, in addition to earthquake magnitudes for the occurrence and properties of pulses produced by the forward directivity effect. 
We finally quantify and discuss within- and between-event variabilities of pulse properties at short distances.
Y1  - 2021
U6  - https://doi.org/10.1785/0120200376
SN  - 0037-1106
SN  - 1943-3573
VL  - 112
IS  - 1
SP  - 361
EP  - 380
PB  - Seismological Society of America
CY  - El Cerito, Calif.
ER  - 
TY  - JOUR
A1  - Wutzler, Bianca
A1  - Hudson, Paul
A1  - Thieken, Annegret
T1  - Adaptation strategies of flood-damaged businesses in Germany
JF  - Frontiers in water
N2  - Flood risk management in Germany follows an integrative approach in which both private households and businesses can make an important contribution to reducing flood damage by implementing property-level adaptation measures. While the flood adaptation behavior of private households has already been widely researched, comparatively less attention has been paid to the adaptation strategies of businesses. However, their ability to cope with flood risk plays an important role in the social and economic development of a flood-prone region. Therefore, using quantitative survey data, this study aims to identify different strategies and adaptation drivers of 557 businesses damaged by a riverine flood in 2013 and 104 businesses damaged by pluvial or flash floods between 2014 and 2017. Our results indicate that a low perceived self-efficacy may be an important factor that can reduce the motivation of businesses to adapt to flood risk. Furthermore, property-owners tended to act more proactively than tenants. In addition, high experience with previous flood events and low perceived response costs could strengthen proactive adaptation behavior. These findings should be considered in business-tailored risk communication.
KW  - risk management
KW  - climate change adaptation
KW  - floods
KW  - disaster risk
KW  - reduction
KW  - Germany
KW  - precaution
KW  - emergency management
Y1  - 2022
U6  - https://doi.org/10.3389/frwa.2022.932061
SN  - 2624-9375
VL  - 4
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Wolf, Sebastian G.
A1  - Huismans, Ritske S.
A1  - Braun, Jean
A1  - Yuan, Xiaoping
T1  - Topography of mountain belts controlled by rheology and surface processes
JF  - Nature : the international weekly journal of science
N2  - It is widely recognized that collisional mountain belt topography is generated by crustal thickening and lowered by river bedrock erosion, linking climate and tectonics(1-4). However, whether surface processes or lithospheric strength control mountain belt height, shape and longevity remains uncertain. Additionally, how to reconcile high erosion rates in some active orogens with long-term survival of mountain belts for hundreds of millions of years remains enigmatic. Here we investigate mountain belt growth and decay using a new coupled surface process(5,6) and mantle-scale tectonic model(7). End-member models and the new non-dimensional Beaumont number, Bm, quantify how surface processes and tectonics control the topographic evolution of mountain belts, and enable the definition of three end-member types of growing orogens: type 1, non-steady state, strength controlled (Bm > 0.5); type 2, flux steady state(8), strength controlled (Bm approximate to 0.4-0.5); and type 3, flux steady state, erosion controlled (Bm < 0.4). Our results indicate that tectonics dominate in Himalaya-Tibet and the Central Andes (both type 1), efficient surface processes balance high convergence rates in Taiwan (probably type 2) and surface processes dominate in the Southern Alps of New Zealand (type 3). Orogenic decay is determined by erosional efficiency and can be subdivided into two phases with variable isostatic rebound characteristics and associated timescales. The results presented here provide a unified framework explaining how surface processes and lithospheric strength control the height, shape, and longevity of mountain belts.
Y1  - 2022
U6  - https://doi.org/10.1038/s41586-022-04700-6
SN  - 0028-0836
SN  - 1476-4687
VL  - 606
IS  - 7914
SP  - 516
EP  - 521
PB  - Nature portfolio
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Wilhelms, Andre
A1  - Börsig, Nicolas
A1  - Yang, Jingwei
A1  - Holbach, Andreas
A1  - Norra, Stefan
T1  - Insights into phytoplankton dynamics and water quality monitoring with the BIOFISH at the Elbe River, Germany
JF  - Water
N2  - Understanding the key factors influencing the water quality of large river systems forms an important basis for the assessment and protection of cross-regional ecosystems and the implementation of adapted water management concepts. However, identifying these factors requires in-depth comprehension of the unique environmental systems, which can only be achieved by detailed water quality monitoring.
Within the scope of the joint science and sports event "Elbschwimmstaffel" (swimming relay on the river Elbe) in June/July 2017 organized by the German Ministry of Education and Research, water quality data were acquired along a 550 km long stretch of the Elbe River in Germany. During the survey, eight physiochemical water quality parameters were recorded in high spatial and temporal resolution with the BIOFISH multisensor system. Multivariate statistical methods were applied to identify and delineate processes influencing the water quality. 
The BIOFISH dataset revealed that phytoplankton activity has a major impact on the water quality of the Elbe River in the summer months. The results suggest that phytoplankton biomass constitutes a substantial proportion of the suspended particles and that photosynthetic activity of phytoplankton is closely related to significant temporal changes in pH and oxygen saturation.
An evaluation of the BIOFISH data based on the combination of statistical analysis with weather and discharge data shows that the hydrological and meteorological history of the sampled water body was the main driver of phytoplankton dynamics. This study demonstrates the capacity of longitudinal river surveys with the BIOFISH or similar systems for water quality assessment, the identification of pollution sources and their utilization for online in situ monitoring of rivers.
KW  - water quality
KW  - phytoplankton
KW  - river dynamics
KW  - multisensor system
KW  - online
KW  - monitoring
KW  - high spatial resolution
KW  - multivariate statistics
Y1  - 2022
U6  - https://doi.org/10.3390/w14132078
SN  - 2073-4441
VL  - 14
IS  - 13
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - West, Charles
A1  - Rosolem, Rafael
A1  - MacDonald, Alan M.
A1  - Cuthbert, Mark O.
A1  - Wagener, Thorsten
T1  - Understanding process controls on groundwater recharge variability across Africa through recharge landscapes
JF  - Journal of hydrology
N2  - Groundwater is critical in supporting current and future reliable water supply throughout Africa. Although continental maps of groundwater storage and recharge have been developed, we currently lack a clear understanding on how the controls on groundwater recharge vary across the entire continent. Reviewing the existing literature, we synthesize information on reported groundwater recharge controls in Africa. We find that 15 out of 22 of these controls can be characterised using global datasets. We develop 11 descriptors of climatic, topographic, vegetation, soil and geologic properties using global datasets, to characterise groundwater recharge controls in Africa. These descriptors cluster Africa into 15 Recharge Landscape Units for which we expect recharge controls to be similar. Over 80% of the continents land area is organized by just nine of these units. We also find that aggregating the Units by similarity into four broader Recharge Landscapes (Desert, Dryland, Wet tropical and Wet tropical forest) provides a suitable level of landscape organisation to explain differences in ground-based long-term mean annual recharge and recharge ratio (annual recharge / annual precipitation) estimates. Furthermore, wetter Recharge Landscapes are more efficient in converting rainfall to recharge than drier Recharge Landscapes as well as having higher annual recharge rates. In Dryland Recharge Landscapes, we found that annual recharge rates largely varied according to mean annual precipitation, whereas recharge ratio estimates increase with increasing monthly variability in P-PET. However, we were unable to explain why ground based estimates of recharge signatures vary across other Recharge Landscapes, in which there are fewer ground based recharge estimates, using global datasets alone. Even in dryland regions, there is still considerable unexplained variability in the estimates of annual recharge and recharge ratio, stressing the limitations of global datasets for investigating ground-based information.
KW  - Groundwater recharge
KW  - Africa
KW  - Recharge controls
KW  - Ground-based estimates
KW  - Landscapes
KW  - Comparative hydrology
Y1  - 2022
U6  - https://doi.org/10.1016/j.jhydrol.2022.127967
SN  - 0022-1694
SN  - 1879-2707
VL  - 612
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Vorogushyn, Sergiy
A1  - Apel, Heiko
A1  - Kemter, Matthias
A1  - Thieken, Annegret
T1  - Analyse der Hochwassergefährdung im Ahrtal unter Berücksichtigung historischer Hochwasser
T1  - Analysis of flood hazard in the Ahr Valley considering historical floods
JF  - Hydrologie und Wasserbewirtschaftung
N2  - The flood disaster in July 2021 in western Germany calls for a critical discussion on flood hazard assessment, revision of flood hazard maps and communication of extreme flood scenarios. In the presented work, extreme value analysis was carried out for annual maximum peak flow series at the Altenahr gauge on the river Ahr. We compared flood statistics with and without considering historical flood events. An estimate for the return period of the recent flood based on the Generalized Extreme Value (GEV) distribution considering historical floods ranges between about 2600 and above 58700 years (90% confidence interval) with a median of approximately 8600 years, whereas an estimate based on the 74-year long systematically recorded flow series would theoretically exceed 100 million years. Consideration of historical floods dramatically changes the flood quantiles that are used for the generation of official flood hazard maps. The fitting of the GEV to the time series with historical floods reveals, however, that the model potentially inadequately reflects the flood population. In this case, we might face a mixed sample, in which extreme floods result from very different processes compared to smaller floods. Hence, the probabilities of extreme floods could be much larger than those resulting from a single GEV model. The application of a process-based mixed flood distribution should be explored in future work. <br /> The comparison of the official HQextrem flood maps for the AhrValley with the inundation areas from July 2021 shows a striking discrepancy in the affected areas and calls for revision of design values used to define extreme flood scenarios. The hydrodynamic simulations of a 1000-year return period flood considering historical events and of the 1804 flood scenario compare much better to the flooded areas from July 2021, though both scenarios still underestimated the flood extent. <br /> Particular effects such as clogging of bridges and geomorphological changes of the river channel led to considerably larger flooded areas in July 2021 compared to the simulation results. Based on this analysis, we call for a consistent definition of HQextrem for flood hazard mapping in Germany, and suggest using high flood quantiles in the range of a 1,000-year flood. Flood maps should additionally include model-based reconstructions of the largest, reliably documented historical floods and/or synthetic worst-case scenarios. This would be an important step towards protecting potentially affected population and disaster management from surprises due to very rare and extreme flood events in future.
N2  - Die Hochwasserkatastrophe im Juli 2021 in Westdeutschland erfordert eine kritische Diskussion über die Abschätzung der Hochwassergefährdung, Aktualisierung von Hochwassergefahrenkarten und Kommunikation von extremen Hochwasserszenarien. In der vorliegenden Arbeit wurde die Extremwertstatistik für die jährlichen maximalen Spitzenabflüsse am Pegel Altenahr im Ahrtal mit und ohne Berücksichtigung historischer Hochwasser berechnet und verglichen. Die Schätzung der Wiederkehrperiode für das aktuelle Hochwasser mittels Generalisierter Extremwertverteilung (GEV) unter Berücksichtigung historischer Hochwasser schwankt zwischen etwa 2.600 und über 58.700 Jahren (90%-Konfidenzintervall) mit einem Median bei etwa 8.600 Jahren, wogegen die Schätzung, die nur auf der systematisch gemessenen Abflusszeitreihe von 74 Jahren basiert, theoretisch eine Wiederkehrperiode von über 100 Millionen Jahren ergeben würde. Die Berücksichtigung der historischen Hochwasser führt zu einer dramatischen Änderung der Hochwasserquan-
tile, die für eine Gefahrenkartierung zugrunde gelegt werden. Die Anpassung der GEV an die Zeitreihe mit historischen Hochwassern zeigt dennoch, dass das GEV-Modell möglicherweise die Grundgesamtheit der Hochwasser im Ahrtal nicht adäquat abbilden kann. Es könnte sich im vorliegenden Fall um eine gemischte Stichprobe handeln, in der die extremen Hochwasser im Vergleich zu kleineren Ereignissen durch besondere Prozesse hervorgerufen werden. Somit könnten die Wahrscheinlichkeiten von extremen Hochwassern deutlich größer sein, als aus dem GEV-Modell hervorgeht. Hier sollte in Zukunft die Anwendung einer prozessbasierten Mischverteilung
untersucht werden. Der Vergleich von amtlichen Gefahrenkarten zu Extremhochwassern (HQextrem) im Ahrtal mit den Überflutungsflächen vom Juli 2021
zeigt eine deutliche Diskrepanz in den betroffenen Gebieten und die Notwendigkeit, die Grundlagen zur Erstellung der Extremszenarien zu überdenken. Die hydrodynamisch-numerischen Simulationen von 1.000-jährlichen Hochwassern (HQ1000) unter Berücksichtigung historischer Ereignisse und des größten historischen Hochwassers 1804 können die Gefährdung des Juli-Hochwassers 2021 deutlich besser widerspiegeln, wenngleich auch diese beiden Szenarien die Überflutungsflächen unterschätzen. Besondere Effekte wie die Verklausung von Brücken und die geomorphologischen Änderungen im Flussschlauch führten zu noch größeren Überflutungs- flächen im Juli 2021, als die Simulationsergebnisse zeigten. Basierend auf dieser Analyse wird eine einheitliche Festlegung von HQextrem bei Hochwassergefahrenkartierungen in Deutschland vorgeschlagen, die sich an höheren Hochwasserquantilen im Bereich von HQ1000 orientiert. Zusätzlich sollen simulationsbasierte Rekonstruktionen von den größten verlässlich dokumentierten historischen Hochwassern und/oder synthetische Worst-Case-Szenarien in den Hochwassergefahrenkarten gesondert dargestellt werden. Damit wird ein wichtiger Beitrag geleistet, um die potenziell betroffene Bevölkerung und das Katastrophenmanagement vor Überraschungen durch sehr seltene und extreme Hochwasser in Zukunft besser zu schützen.
KW  - Extreme value statistics
KW  - historical floods
KW  - flood hazard mapping;
KW  - inundation simulation
KW  - Ahr River
KW  - Extremwertstatistik
KW  - historische Hochwasser
KW  - Gefahrenkarten
KW  - Überflutungssimulation
KW  - Ahr
Y1  - 2022
U6  - https://doi.org/10.5675/HyWa_2022.5_2
SN  - 1439-1783
VL  - 66
IS  - 5
SP  - 244
EP  - 254
PB  - Bundesanst. für Gewässerkunde
CY  - Koblenz
ER  - 
TY  - JOUR
A1  - Viltres, Renier
A1  - Nobile, Adriano
A1  - Vasyura-Bathke, Hannes
A1  - Trippanera, Daniele
A1  - Xu, Wenbin
A1  - Jónsson, Sigurjón
T1  - Transtensional rupture within a diffuse plate boundary zone during the 2020 M-w 6.4 Puerto Rico earthquake
JF  - Seismological research letters
N2  - On 7 January 2020, an M-w 6.4 earthquake occurred in the northeastern Caribbean, a few kilometers offshore of the island of Puerto Rico. It was the mainshock of a complex seismic sequence, characterized by a large number of energetic earthquakes illuminating an east-west elongated area along the southwestern coast of Puerto Rico. Deformation fields constrained by Interferometric Synthetic Aperture Radar and Global Navigation Satellite System data indicate that the coseismic movements affected only the western part of the island. To assess the mainshock's source fault parameters, we combined the geodetically derived coseismic deformation with teleseismic waveforms using Bayesian inference. The results indicate a roughly east-west oriented fault, dipping northward and accommodating similar to 1.4 m of transtensional motion. Besides, the determined location and orientation parameters suggest an offshore continuation of the recently mapped North Boqueron Bay-Punta Montalva fault in southwest Puerto Rico. This highlights the existence of unmapped faults with moderate-to-large earthquake potential within the Puerto Rico region.
Y1  - 2021
U6  - https://doi.org/10.1785/0220210261
SN  - 0895-0695
SN  - 1938-2057
VL  - 93
IS  - 2A
SP  - 567
EP  - 583
PB  - Seismological Society of America
CY  - Boulder, Colo.
ER  - 
TY  - JOUR
A1  - van Geffen, Femke
A1  - Heim, Birgit
A1  - Brieger, Frederic
A1  - Geng, Rongwei
A1  - Shevtsova, Iuliia A.
A1  - Schulte, Luise
A1  - Stuenzi, Simone M.
A1  - Bernhardt, Nadine
A1  - Troeva, Elena
A1  - Pestryakova, Luidmila Agafyevna
A1  - Zakharov, Evgenii S.
A1  - Pflug, Bringfried
A1  - Herzschuh, Ulrike
A1  - Kruse, Stefan
T1  - SiDroForest: a comprehensive forest inventory of Siberian boreal forest investigations including drone-based point clouds, individually labeled trees, synthetically generated tree crowns, and Sentinel-2 labeled image patches
JF  - Earth system science data
N2  - The SiDroForest (Siberian drone-mapped forest inventory) data collection is an attempt to remedy the scarcity of forest structure data in the circumboreal region by providing adjusted and labeled tree-level and vegetation plot-level data for machine learning and upscaling purposes. We present datasets of vegetation composition and tree and plot level forest structure for two important vegetation transition zones in Siberia, Russia; the summergreen-evergreen transition zone in Central Yakutia and the tundra-taiga transition zone in Chukotka (NE Siberia). The SiDroForest data collection consists of four datasets that contain different complementary data types that together support in-depth analyses from different perspectives of Siberian Forest plot data for multi-purpose applications. i. Dataset 1 provides unmanned aerial vehicle (UAV)-borne data products covering the vegetation plots surveyed during fieldwork (Kruse et al., 2021, ). The dataset includes structure-from-motion (SfM) point clouds and red-green-blue (RGB) and red-green-near-infrared (RGN) orthomosaics. From the orthomosaics, point-cloud products were created such as the digital elevation model (DEM), canopy height model (CHM), digital surface model (DSM) and the digital terrain model (DTM). The point-cloud products provide information on the three-dimensional (3D) structure of the forest at each plot. Dataset 2 contains spatial data in the form of point and polygon shapefiles of 872 individually labeled trees and shrubs that were recorded during fieldwork at the same vegetation plots (van Geffen et al., 2021c, ). The dataset contains information on tree height, crown diameter, and species type. These tree and shrub individually labeled point and polygon shapefiles were generated on top of the RGB UVA orthoimages. The individual tree information collected during the expedition such as tree height, crown diameter, and vitality are provided in table format. This dataset can be used to link individual information on trees to the location of the specific tree in the SfM point clouds, providing for example, opportunity to validate the extracted tree height from the first dataset. The dataset provides unique insights into the current state of individual trees and shrubs and allows for monitoring the effects of climate change on these individuals in the future. Dataset 3 contains a synthesis of 10 000 generated images and masks that have the tree crowns of two species of larch ( and ) automatically extracted from the RGB UAV images in the common objects in context (COCO) format (van Geffen et al., 2021a, ). As machine-learning algorithms need a large dataset to train on, the synthetic dataset was specifically created to be used for machine-learning algorithms to detect Siberian larch species. Larix gmeliniiLarix cajanderiDataset 4 contains Sentinel-2 (S-2) Level-2 bottom-of-atmosphere processed labeled image patches with seasonal information and annotated vegetation categories covering the vegetation plots (van Geffen et al., 2021b, ). The dataset is created with the aim of providing a small ready-to-use validation and training dataset to be used in various vegetation-related machine-learning tasks. It enhances the data collection as it allows classification of a larger area with the provided vegetation classes. The SiDroForest data collection serves a variety of user communities. <br /> The detailed vegetation cover and structure information in the first two datasets are of use for ecological applications, on one hand for summergreen and evergreen needle-leaf forests and also for tundra-taiga ecotones. Datasets 1 and 2 further support the generation and validation of land cover remote-sensing products in radar and optical remote sensing. In addition to providing information on forest structure and vegetation composition of the vegetation plots, the third and fourth datasets are prepared as training and validation data for machine-learning purposes. For example, the synthetic tree-crown dataset is generated from the raw UAV images and optimized to be used in neural networks. Furthermore, the fourth SiDroForest dataset contains S-2 labeled image patches processed to a high standard that provide training data on vegetation class categories for machine-learning classification with JavaScript Object Notation (JSON) labels provided. The SiDroForest data collection adds unique insights into remote hard-to-reach circumboreal forest regions.
Y1  - 2022
U6  - https://doi.org/10.5194/essd-14-4967-2022
SN  - 1866-3508
SN  - 1866-3516
VL  - 14
IS  - 11
SP  - 4967
EP  - 4994
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Valenzuela-Malebran, Carla
A1  - Cesca, Simone
A1  - Lopez-Comino, José Ángel
A1  - Zeckra, Martin
A1  - Krüger, F.
A1  - Dahm, Torsten
T1  - Source mechanisms and rupture processes of the Jujuy seismic nest, Chile-Argentina border
JF  - Journal of South American earth sciences
N2  - The Altiplano-Puna plateau, in Central Andes, is the second-largest continental plateau on Earth, extending between 22 degrees and 27 degrees S at an average altitude of 4400 m. The Puna plateau has been formed in consequence of the subduction of the oceanic Nazca Plate beneath the continental South American plate, which has an average crustal thickness of 50 km at this location. A large seismicity cluster, the Jujuy cluster, is observed at depth of 150-250 km beneath the central region of the Puna plateau. The cluster is seismically very active, with hundreds of earthquakes reported and a peak magnitude MW 6.6 on 25th August 2006. The cluster is situated in one of three band of intermediate-depth focus seismicity, which extend parallel to the trench roughly North to South. It has been hypothesized that the Jujuy cluster could be a seismic nest, a compact seismogenic region characterized by a high stationary activity relative to its surroundings. In this study, we collected more than 40 years of data from different catalogs and proof that the cluster meets the three conditions of a seismic nest. Compared to other known intermediate depth nests at Hindu Kush (Afganisthan) or Bucaramanga (Colombia), the Jujuy nest presents an outstanding seismicity rate, with more than 100 M4+ earthquakes per year. We additionally performed a detailed analysis of the rupture process of some of the largest earthquakes in the nest, by means of moment tensor inversion and directivity analysis. We focused on the time period 2017-2018, where the seismic monitoring was the most extended. Our results show that earthquakes in the nest take place within the eastward subducting oceanic plate, but rupture along sub-horizontal planes dipping westward. We suggest that seismicity at Jujuy nest is controlled by dehydration processes, which are also responsible for the generation of fluids ascending to the crust beneath the Puna volcanic region. We use the rupture plane and nest geometry to provide a constraint to maximal expected magnitude, which we estimate as MW -6.7.
KW  - Seismic nest
KW  - Intermediate-deep earthquakes
KW  - Cluster analysis moment
KW  - tensor inversion
KW  - directivity analysis
Y1  - 2022
U6  - https://doi.org/10.1016/j.jsames.2022.103887
SN  - 0895-9811
SN  - 1873-0647
VL  - 117
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Türker, Elif
A1  - Cotton, Fabrice
A1  - Pilz, Marco
A1  - Weatherill, Graeme
T1  - Analysis of the 2019 Mw 5.8 Silivri earthquake ground motions
BT  - evidence of systematic azimuthal variations associated with directivity effects
JF  - Seismological research letters
N2  - The main Marmara fault (MMF) extends for 150 km through the Sea of Marmara and forms the only portion of the North Anatolian fault zone that has not ruptured in a large event (Mw >7) for the last 250 yr. Accordingly, this portion is potentially a major source contributing to the seismic hazard of the Istanbul region. On 26 September 2019, a sequence of moderate-sized events started along the MMF only 20 km south of Istanbul and were widely felt by the population. The largest three events, 26 September Mw 5.8 (10:59 UTC), 26 September 2019 Mw 4.1 (11:26 UTC), and 20 January 2020 Mw 4.7 were recorded by numerous strong-motion seismic stations and the resulting ground motions were compared to the predicted means resulting from a set of the most recent ground-motion prediction equations (GMPEs). The estimated residuals were used to investigate the spatial variation of ground motion across the Marmara region. Our results show a strong azimuthal trend in ground-motion residuals, which might indicate systematically repeating directivity effects toward the eastern Marmara region.
Y1  - 2022
U6  - https://doi.org/10.1785/0220210168
SN  - 0895-0695
SN  - 1938-2057
VL  - 93
IS  - 2A
SP  - 693
EP  - 705
PB  - Seismological Society of America
CY  - Boulder, Colo.
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
A1  - Marwan, Norbert
T1  - Introduction-time series analysis for Earth, climate and life interactions
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
Y1  - 2022
U6  - https://doi.org/10.1016/j.quascirev.2022.107475
SN  - 0277-3791
SN  - 1873-457X
VL  - 284
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Tofelde, Stefanie
A1  - Bufe, Aaron
A1  - Turowski, Jens M.
T1  - Hillslope Sediment Supply Limits Alluvial Valley Width
JF  - AGU Advances
N2  - River-valley morphology preserves information on tectonic and climatic conditions that shape landscapes. Observations suggest that river discharge and valley-wall lithology are the main controls on valley width. Yet, current models based on these observations fail to explain the full range of cross-sectional valley shapes in nature, suggesting hitherto unquantified controls on valley width. In particular, current models cannot explain the existence of paired terrace sequences that form under cyclic climate forcing. Paired river terraces are staircases of abandoned floodplains on both valley sides, and hence preserve past valley widths. Their formation requires alternating phases of predominantly river incision and predominantly lateral planation, plus progressive valley narrowing. While cyclic Quaternary climate changes can explain shifts between incision and lateral erosion, the driving mechanism of valley narrowing is unknown. Here, we extract valley geometries from climatically formed, alluvial river-terrace sequences and show that across our dataset, the total cumulative terrace height (here: total valley height) explains 90%–99% of the variance in valley width at the terrace sites. This finding suggests that valley height, or a parameter that scales linearly with valley height, controls valley width in addition to river discharge and lithology. To explain this valley-width-height relationship, we reformulate existing valley-width models and suggest that, when adjusting to new boundary conditions, alluvial valleys evolve to a width at which sediment removal from valley walls matches lateral sediment supply from hillslope erosion. Such a hillslope-channel coupling is not captured in current valley-evolution models. Our model can explain the existence of paired terrace sequences under cyclic climate forcing and relates valley width to measurable field parameters. Therefore, it facilitates the reconstruction of past climatic and tectonic conditions from valley topography.
Y1  - 2022
U6  - https://doi.org/10.1029/2021AV000641
SN  - 2576-604X
PB  - American Geophysical Union (AGU); Wiley
CY  - Hoboken, New Jersey, USA
ER  - 
TY  - JOUR
A1  - Tella, Timothy Oluwatobi
A1  - Winterleitner, Gerd
A1  - Mutti, Maria
T1  - Investigating the role of differential biotic production on carbonate geometries through stratigraphic forward modelling and sensitivity analysis
BT  - the Llucmajor example
JF  - Petroleum geoscience
N2  - The geometry of carbonate platforms reflects the interaction of several factors. However, the impact of carbonate-producing organisms has been poorly investigated so far. This study applies stratigraphic forward modelling (SFM) and sensitivity analysis to examine, referenced to the Miocene Llucmajor Platform, the effect of changes of dominant biotic production in the oligophotic and euphotic zones on platform geometry. Our results show that the complex interplay of carbonate production rates, bathymetry and variations in accommodation space control the platform geometry. The main driver of progradation is the oligophotic production of rhodalgal sediments during the lowstands. This study demonstrates that platform geometry and internal architecture varies significantly according to the interaction of the predominant carbonate-producing biotas. The input parameters for this study are based on well-understood Miocene carbonate biotas with characteristic euphotic, oligophotic and photo-independent carbonate production in which it is crucial that each carbonate-producing class is modelled explicitly within the simulation run and not averaged with a single carbonate production-depth profile. This is important in subsurface exploration studies based on stratigraphic forward models where the overall platform geometry may be approximated through calibration runs, and constrained by seismic surveys and wellbores. However, the internal architecture is likely to be oversimplified without an in-depth understanding of the target carbonate system and a transfer to forward modelling parameters.
Y1  - 2022
U6  - https://doi.org/10.1144/petgeo2021-053
SN  - 1354-0793
SN  - 2041-496X
VL  - 28
IS  - 2
PB  - Geological Soc. Publ. House
CY  - Bath
ER  - 
TY  - JOUR
A1  - Tawfik, Ahmed Y.
A1  - Ondrak, Robert
A1  - Winterleitner, Gerd
A1  - Mutti, Maria
T1  - Source rock evaluation and petroleum system modeling of the East Beni Suef Basin, north Eastern Desert, Egypt
JF  - Journal of African earth sciences
N2  - This study deals with the East Beni Suef Basin (Eastern Desert, Egypt) and aims to evaluate the source-generative potential, reconstruct the burial and thermal history, examine the most influential parameters on thermal maturity modeling, and improve on the models already published for the West Beni Suef to ultimately formulate a complete picture of the whole basin evolution.
Source rock evaluation was carried out based on TOC, Rock-Eval pyrolysis, and visual kerogen petrography analyses. Three kerogen types (II, II/III, and III) are distinguished in the East Beni Suef Basin, where the Abu Roash "F" Member acts as the main source rock with good to excellent source potential, oil-prone mainly type II kerogen, and immature to marginal maturity levels. 
The burial history shows four depositional and erosional phases linked with the tectonic evolution of the basin. A hiatus (due to erosion or non-deposition) has occurred during the Late Eocene-Oligocene in the East Beni Suef Basin, while the West Beni Suef Basin has continued subsiding. 
Sedimentation began later (Middle to Late Albian) with lower rates in the East Beni Suef Basin compared with the West Beni Suef Basin (Early Albian). The Abu Roash "F" source rock exists in the early oil window with a present-day transformation ratio of about 19% and 21% in the East and West Beni Suef Basin, respectively, while the Lower Kharita source rock, which is only recorded in the West Beni Suef Basin, has reached the late oil window with a present-day transformation ratio of about 70%. 
The magnitude of erosion and heat flow have proportional and mutual effects on thermal maturity. 
We present three possible scenarios of basin modeling in the East Beni Suef Basin concerning the erosion from the Apollonia and Dabaa formations. 
Results of this work can serve as a basis for subsequent 2D and/or 3D basin modeling, which are highly recommended to further investigate the petroleum system evolution of the Beni Suef Basin.
KW  - source rock evaluation
KW  - Kerogen petrography
KW  - basin modeling
KW  - sensitivity
KW  - analysis
KW  - Beni Suef Basin
KW  - Egypt
Y1  - 2022
U6  - https://doi.org/10.1016/j.jafrearsci.2022.104575
SN  - 1464-343X
SN  - 1879-1956
VL  - 193
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Svennevig, Kristian
A1  - Hermanns, Reginald L.
A1  - Keiding, Marie
A1  - Binder, Daniel
A1  - Citterio, Michele
A1  - Dahl-Jensen, Trine
A1  - Mertl, Stefan
A1  - Sørensen, Erik Vest
A1  - Voss, Peter Henrik
T1  - A large frozen debris avalanche entraining warming permafrost ground-the June 2021 Assapaat landslibe, West Greenland
JF  - Landslides
N2  - A large landslide (frozen debris avalanche) occurred at Assapaat on the south coast of the Nuussuaq Peninsula in Central West Greenland on June 13, 2021, at 04:04 local time. We present a compilation of available data from field observations, photos, remote sensing, and seismic monitoring to describe the event. Analysis of these data in combination with an analysis of pre- and post-failure digital elevation models results in the first description of this type of landslide. The frozen debris avalanche initiated as a 6.9 * 10(6) m(3) failure of permafrozen talus slope and underlying colluvium and till at 600-880 m elevation. It entrained a large volume of permafrozen colluvium along its 2.4 km path in two subsequent entrainment phases accumulating a total volume between 18.3 * 10(6) and 25.9 * 10(6) m(3). About 3.9 * 10(6) m(3) is estimated to have entered the Vaigat strait; however, no tsunami was reported, or is evident in the field. This is probably because the second stage of entrainment along with a flattening of slope angle reduced the mobility of the frozen debris avalanche. We hypothesise that the initial talus slope failure is dynamically conditioned by warming of the ice matrix that binds the permafrozen talus slope. When the slope ice temperature rises to a critical level, its shear resistance is reduced, resulting in an unstable talus slope prone to failure. Likewise, we attribute the large-scale entrainment to increasing slope temperature and take the frozen debris avalanche as a strong sign that the permafrost in this region is increasingly at a critical state. Global warming is enhanced in the Arctic and frequent landslide events in the past decade in Western Greenland let us hypothesise that continued warming will lead to an increase in the frequency and magnitude of these types of landslides. Essential data for critical arctic slopes such as precipitation, snowmelt, and ground and surface temperature are still missing to further test this hypothesis. It is thus strongly required that research funds are made available to better predict the change of landslide threat in the Arctic.
KW  - Assapaat landslide
KW  - Slope temperature
KW  - Global warming
Y1  - 2022
U6  - https://doi.org/10.1007/s10346-022-01922-7
SN  - 1612-510X
SN  - 1612-5118
VL  - 19
SP  - 2549
EP  - 2567
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Sudibyo, Maria R. P.
A1  - Eibl, Eva P. S.
A1  - Hainzl, Sebastian
A1  - Hersir, Gylfi Páll
T1  - Eruption Forecasting of Strokkur Geyser, Iceland, Using Permutation Entropy
JF  - Journal of geophysical research : Solid earth
N2  - A volcanic eruption is usually preceded by seismic precursors, but their interpretation and use for forecasting the eruption onset time remain a challenge. A part of the eruptive processes in open conduits of volcanoes may be similar to those encountered in geysers. Since geysers erupt more often, they are useful sites for testing new forecasting methods. We tested the application of Permutation Entropy (PE) as a robust method to assess the complexity in seismic recordings of the Strokkur geyser, Iceland. Strokkur features several minute-long eruptive cycles, enabling us to verify in 63 recorded cycles whether PE behaves consistently from one eruption to the next one. We performed synthetic tests to understand the effect of different parameter settings in the PE calculation. Our application to Strokkur shows a distinct, repeating PE pattern consistent with previously identified phases in the eruptive cycle. We find a systematic increase in PE within the last 15 s before the eruption, indicating that an eruption will occur. We quantified the predictive power of PE, showing that PE performs better than seismic signal strength or quiescence when it comes to forecasting eruptions.
KW  - permutation entropy
KW  - forecasting
KW  - geyser
KW  - eruption
KW  - hydrothermal system;
KW  - volcano-seismology
Y1  - 2022
U6  - https://doi.org/10.1029/2022JB024840
SN  - 2169-9313
SN  - 2169-9356
VL  - 127
IS  - 10
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Stuenzi, Simone Maria
A1  - Kruse, Stefan
A1  - Boike, Julia
A1  - Herzschuh, Ulrike
A1  - Oehme, Alexander
A1  - Pestryakova, Luidmila A.
A1  - Westermann, Sebastian
A1  - Langer, Moritz
T1  - Thermohydrological impact of forest disturbances on ecosystem-protected permafrost
JF  - Journal of geophysical research : Biogeosciences
N2  - Boreal forests cover over half of the global permafrost area and protect underlying permafrost. Boreal forest development, therefore, has an impact on permafrost evolution, especially under a warming climate. 

Forest disturbances and changing climate conditions cause vegetation shifts and potentially destabilize the carbon stored within the vegetation and permafrost. Disturbed permafrost-forest ecosystems can develop into a dry or swampy bush- or grasslands, shift toward broadleaf- or evergreen needleleaf-dominated forests, or recover to the pre-disturbance state. 

An increase in the number and intensity of fires, as well as intensified logging activities, could lead to a partial or complete ecosystem and permafrost degradation. We study the impact of forest disturbances (logging, surface, and canopy fires) on the thermal and hydrological permafrost conditions and ecosystem resilience. 

We use a dynamic multilayer canopy-permafrost model to simulate different scenarios at a study site in eastern Siberia. We implement expected mortality, defoliation, and ground surface changes and analyze the interplay between forest recovery and permafrost. We find that forest loss induces soil drying of up to 44%, leading to lower active layer thicknesses and abrupt or steady decline of a larch forest, depending on disturbance intensity. 

Only after surface fires, the most common disturbances, inducing low mortality rates, forests can recover and overpass pre-disturbance leaf area index values. We find that the trajectory of larch forests after surface fires is dependent on the precipitation conditions in the years after the disturbance. Dryer years can drastically change the direction of the larch forest development within the studied period.
KW  - permafrost
KW  - boreal forest
KW  - periglacial process
KW  - Siberia
KW  - larch forest
KW  - disturbance
Y1  - 2022
U6  - https://doi.org/10.1029/2021JG006630
SN  - 2169-8953
SN  - 2169-8961
VL  - 127
IS  - 5
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Stoltnow, Malte
A1  - Lüders, Volker
A1  - Graaf, Stefan de
A1  - Niedermann, Samuel
T1  - A geochemical study of the Sweet Home mine, Colorado Mineral Belt, USA
BT  - formation of deep hydrothermal vein-type molybdenum greisen and base metal mineralization
JF  - Mineralium deposita : international journal for geology, mineralogy and geochemistry of mineral deposits
N2  - Deep hydrothermal Mo, W, and base metal mineralization at the Sweet Home mine (Detroit City portal) formed in response to magmatic activity during the Oligocene. Microthermometric data of fluid inclusions trapped in greisen quartz and fluorite suggest that the early-stage mineralization at the Sweet Home mine precipitated from low- to medium-salinity (1.5-11.5 wt% equiv. NaCl), CO2-bearing fluids at temperatures between 360 and 415 degrees C and at depths of at least 3.5 km. Stable isotope and noble gas isotope data indicate that greisen formation and base metal mineralization at the Sweet Home mine was related to fluids of different origins. Early magmatic fluids were the principal source for mantle-derived volatiles (CO2, H2S/SO2, noble gases), which subsequently mixed with significant amounts of heated meteoric water. Mixing of magmatic fluids with meteoric water is constrained by delta H-2(w)-delta O-18(w) relationships of fluid inclusions. The deep hydrothermal mineralization at the Sweet Home mine shows features similar to deep hydrothermal vein mineralization at Climax-type Mo deposits or on their periphery. This suggests that fluid migration and the deposition of ore and gangue minerals in the Sweet Home mine was triggered by a deep-seated magmatic intrusion. The findings of this study are in good agreement with the results of previous fluid inclusion studies of the mineralization of the Sweet Home mine and from Climax-type Mo porphyry deposits in the Colorado Mineral Belt.
KW  - Hydrothermal veins
KW  - Fluid inclusion geochemistry
KW  - Fluid mixing
KW  - Ore
KW  - deposition
KW  - Colorado mineral belt
KW  - Molybdenum mineralization
Y1  - 2022
U6  - https://doi.org/10.1007/s00126-022-01102-6
SN  - 0026-4598
SN  - 1432-1866
VL  - 57
IS  - 5
SP  - 801
EP  - 825
PB  - Springer
CY  - Berlin ; Heidelberg
ER  - 
TY  - JOUR
A1  - Stolpmann, Lydia
A1  - Mollenhauer, Gesine
A1  - Morgenstern, Anne
A1  - Hammes, Jens S.
A1  - Boike, Julia
A1  - Overduin, Pier Paul
A1  - Grosse, Guido
T1  - Origin and pathways of dissolved organic carbon in a small catchment in the Lena River Delta
JF  - Frontiers in Earth Science
N2  - The Arctic is rich in aquatic systems and experiences rapid warming due to climate change. The accelerated warming causes permafrost thaw and the mobilization of organic carbon. 
When dissolved organic carbon is mobilized, this DOC can be transported to aquatic systems and degraded in the water bodies and further downstream. Here, we analyze the influence of different landscape components on DOC concentrations and export in a small (6.45 km(2)) stream catchment in the Lena River Delta. 
The catchment includes lakes and ponds, with the flow path from Pleistocene yedoma deposits across Holocene non-yedoma deposits to the river outlet. In addition to DOC concentrations, we use radiocarbon dating of DOC as well as stable oxygen and hydrogen isotopes (delta O-18 and delta D) to assess the origin of DOC. 
We find significantly higher DOC concentrations in the Pleistocene yedoma area of the catchment compared to the Holocene non-yedoma area with medians of 5 and 4.5 mg L-1 (p < 0.05), respectively. When yedoma thaw streams with high DOC concentration reach a large yedoma thermokarst lake, we observe an abrupt decrease in DOC concentration, which we attribute to dilution and lake processes such as mineralization. The DOC ages in the large thermokarst lake (between 3,428 and 3,637 C-14 y BP) can be attributed to a mixing of mobilized old yedoma and Holocene carbon. 
Further downstream after the large thermokarst lake, we find progressively younger DOC ages in the stream water to its mouth, paired with decreasing DOC concentrations. This process could result from dilution with leaching water from Holocene deposits and/or emission of ancient yedoma carbon to the atmosphere. Our study shows that thermokarst lakes and ponds may act as DOC filters, predominantly by diluting incoming waters of higher DOC concentrations or by re-mineralizing DOC to CO2 and CH4. 
Nevertheless, our results also confirm that the small catchment still contributes DOC on the order of 1.2 kg km(-2) per day from a permafrost landscape with ice-rich yedoma deposits to the Lena River.
KW  - Arctic lakes
KW  - ice complex
KW  - yedoma
KW  - thermokarst lakes
KW  - DOC
KW  - aquatic carbon cycle
KW  - permafrost
KW  - radiocarbon dating
Y1  - 2022
U6  - https://doi.org/10.3389/feart.2021.759085
SN  - 2296-6463
VL  - 9
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Stevanato, Luca
A1  - Baroni, Gabriele
A1  - Oswald, Sascha
A1  - Lunardon, Marcello
A1  - Mareš, Vratislav
A1  - Marinello, Francesco
A1  - Moretto, Sandra
A1  - Polo, Matteo
A1  - Sartori, Paolo
A1  - Schattan, Paul
A1  - Rühm, Werner
T1  - An alternative incoming correction for cosmic-ray neutron sensing observations using local muon measurement
JF  - Geophysical research letters
N2  - Measuring the variability of incoming neutrons locally would be usefull for the cosmic-ray neutron sensing (CRNS) method. As the measurement of high energy neutrons is not so easy, alternative particles can be considered for such purpose. Among them, muons are particles created from the same cascade of primary cosmic-ray fluxes that generate neutrons at the ground. In addition, they can be easily detected by small and relatively inexpensive detectors. For these reasons they could provide a suitable local alternative to incoming corrections based on remote neutron monitor data. The reported measurements demonstrated that muon detection system can detect incoming cosmic-ray variations locally. Furthermore the precision of this measurement technique is considered adequate for many CRNS applications.
KW  - CRNS
KW  - soil-moisture
KW  - neutrons
KW  - muons
KW  - cosmic-rays
Y1  - 2022
U6  - https://doi.org/10.1029/2021GL095383
SN  - 0094-8276
SN  - 1944-8007
VL  - 49
IS  - 6
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Smith, Taylor
A1  - Traxl, Dominik
A1  - Boers, Niklas
T1  - Empirical evidence for recent global shifts in vegetation resilience
JF  - Nature climate change
N2  - The authors demonstrate that a vegetation system's ability to recover from disturbances-its resilience-can be estimated from its natural variability. Global patterns of resilience loss and gains since the early 1990s reveal shifts towards widespread resilience loss since the early 2000s. 
The character and health of ecosystems worldwide is tightly coupled to changes in Earth's climate. Theory suggests that ecosystem resilience-the ability of ecosystems to resist and recover from external shocks such as droughts and fires-can be inferred from their natural variability. Here, we quantify vegetation resilience globally with complementary metrics based on two independent long-term satellite records. We first empirically confirm that the recovery rates from large perturbations can be closely approximated from internal vegetation variability across vegetation types and climate zones. On the basis of this empirical relationship, we quantify vegetation resilience continuously and globally from 1992 to 2017. Long-term vegetation resilience trends are spatially heterogeneous, with overall increasing resilience in the tropics and decreasing resilience at higher latitudes. Shorter-term trends, however, reveal a marked shift towards a global decline in vegetation resilience since the early 2000s, particularly in the equatorial rainforest belt.
Y1  - 2022
U6  - https://doi.org/10.1038/s41558-022-01352-2
SN  - 1758-678X
SN  - 1758-6798
VL  - 12
IS  - 5
SP  - 477
EP  - 484
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Singh, Manudeo
A1  - Sinha, Rajiv
A1  - Mishra, Arjit
A1  - Babu, Suresh
T1  - Wetlandscape (dis)connectivity and fragmentation in a large wetland (Haiderpur) in west Ganga plains, India
JF  - Earth surface processes and landforms : the journal of the British Geomorphological Research Group
N2  - Wetlands are dynamic ecosystems that require continuous monitoring and assessment of degradation status to design strategies for their sustainable management. While hydrology provides the primary functional control for the wetland ecosystem, the loss of landscape connectivity influences wetland degradation in a major way as it leads to fragmentation. This article aims to integrate hydrogeomorphic and ecological concepts for the assessment of degradation status and its causal factors for a large wetland in the western Ganga plains, India, the Haiderpur, using a wetlandscape approach. We have used a remote-sensing-based approach, which offers a powerful tool for assessing and linking cross-scale structures, functions, and controls in a wetlandscape. The Haiderpur, a Ramsar site since December 2021, is an artificial wetland located on the right bank of the Ganga River wherein the inflows are controlled by a barrage constructed on the Ganga River apart from smaller tributaries flowing in from the north. A novel aspect of this work is the integration of river dynamics and its connectivity to the wetlandscape to understand the spatiotemporal variability in the waterspread area in the wetland. In this work, we have developed an integrated wetlandscape assessment approach by evaluating wetland's geomorphic and hydrological connectivity status for the period 1993-2019 (25 years) across three different spatial scales - regional, catchment, and wetland. We have highlighted the ecological implications of connectivity and patch dynamics for developing sustainable wetland management plans.
KW  - floodplain wetlands
KW  - Ganga River
KW  - geomorphic connectivity
KW  - wetland
KW  - degradation
KW  - wetland hydrology
Y1  - 2022
U6  - https://doi.org/10.1002/esp.5352
SN  - 0197-9337
SN  - 1096-9837
VL  - 47
IS  - 7
SP  - 1872
EP  - 1887
PB  - Wiley
CY  - New York, NY [u.a.]
ER  - 
TY  - JOUR
A1  - Siegmund, Nicole
A1  - Funk, Roger
A1  - Sommer, Michael
A1  - Avecilla, Fernando
A1  - Esteban Panebianco, Juan
A1  - Iturri, Laura Antonela
A1  - Buschiazzo, Daniel
T1  - Horizontal and vertical fluxes of particulate matter during wind erosion on arable land in the province La Pampa, Argentina
JF  - International journal of sediment research
N2  - A detailed analysis of horizontal and vertical particulate matter (PM) fluxes during wind erosion has been done, based on measurements of PM smaller than 10, 2.5, and 1.0 mu mm, at windward and leeward positions on a measuring field. The three fractions of PM measurement are differently influenced by the increasing wind and shear velocities of the wind. The measured concentrations of the coarser fractions of the fine dust, PM10, and PM2.5, increase with wind and shear velocity, whereas the PM1.0 concentrations show no clear correlation to the shear velocity. The share of PM2.5 on PM10 depends on the measurement height and wind speed and varies between 4 and 12 m/s at the 1 m height ranging from 25% to 7% (average 10%), and at the 4 m height from 39% to 23% (average 30%). Although general relationships between wind speed, PM concentration, and horizontal and vertical fluxes could be found, the contribution of the measuring field was very low, as balances of incoming and outgoing fluxes show. Consequently, the measured PM concentrations are determined from a variety of sources, such as traffic on unpaved roads, cattle drives, tillage operations, and wind erosion, and thus, represent all components of land use and landscape structure in the near and far surroundings of the measuring field. The current results may reflect factors from the landscape scale rather than the influence of field-related variables. The measuring devices used to monitor PM concentrations showed differences of up to 20%, which led to considerable deviations when determining total balances. Differences up to 67% between the calculated fluxes prove the necessity of a previous calibration of the devices used. (c) 2022 International Research and Training Centre on Erosion and Sedimentation/the World Association for Sedimentation and Erosion Research.
KW  - PM10, PM2.5 and PM1.0 concentrations
KW  - Field measurements
KW  - Horizontal
KW  - flux
KW  - Vertical flux
KW  - PM balances
Y1  - 2022
U6  - https://doi.org/10.1016/j.ijsrc.2022.01.004
SN  - 1001-6279
SN  - 2589-7284
VL  - 37
IS  - 5
SP  - 539
EP  - 552
PB  - IRTCES
CY  - Beijing
ER  - 
TY  - JOUR
A1  - Sieber, Melanie Jutta
A1  - Yaxley, Greg
A1  - Hermann, Jörg
T1  - COH-fluid induced metasomatism of peridotites in the forearc mantle
JF  - Contributions to Mineralogy and Petrology
N2  - Devolatilization of subducting lithologies liberates COH-fluids. These may become partially sequestered in peridotites in the slab and the overlying forearc mantle, affecting the cycling of volatiles and fluid mobile elements in subduction zones. Here we assess the magnitudes, timescales and mechanism of channelized injection of COH-fluids doped with Ca-aq(2+), Sr-aq(2+) and Ba-aq(2+) into the dry forearc mantle by performing piston cylinder experiments between 1-2.5 GPa and 600-700 degrees C. Cylindrical cores of natural spinel-bearing harzburgites were used as starting materials. Based on mineral assemblage and composition three reaction zones are distinguishable from the rim towards the core of primary olivine and orthopyroxene grains. Zone 1 contains carbonates + quartz +/- kyanite and zone 2 contains carbonates + talc +/- chlorite. Olivine is further replaced in zone 3 by either antigorite+ magnesite or magnesite +talc within or above antigorite stability, respectively. Orthopyroxene is replaced in zone 3 by talc + chlorite. Mineral assemblages and the compositions of secondary minerals depend on fluid composition and the replaced primary silicate. The extent of alteration depends on fluid CO2 content and fluid/rock-ratio, and is further promoted by fluid permeable reaction zones and reaction driven cracking. Our results show that COH-fluid induced metasomatism of the forearc mantle is self-perpetuating and efficient at sequestering Ca-aq(2+), Sr-aq(2+), Ba-aq(2+) and CO2aq into newly formed carbonates. This process is fast with 90% of the available C sequestered and nearly 50% of the initial minerals altered at 650 degrees C, 2 GPa within 55 h. The dissolution of primary silicates under high COH-fluid/rock-ratios, as in channelized fluid flow, enriches SiO2aq in the fluid, while CO2aq is sequestered into carbonates. In an open system, the remaining CO2-depleted, Si-enriched aqueous fluid may cause Si-metasomatism in the forearc further away from the injection of the COH-fluid into peridotite.
KW  - Carbonation
KW  - Deep carbon cycle
KW  - COH-fluid
KW  - Forearc
KW  - HP-experiments
Y1  - 2022
U6  - https://doi.org/10.1007/s00410-022-01905-w
SN  - 0010-7999
SN  - 1432-0967
VL  - 177
IS  - 4
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Shprits, Yuri Y.
A1  - Allison, Hayley J.
A1  - Wang, Dedong
A1  - Drozdov, Alexander
A1  - Szabo-Roberts, Matyas
A1  - Zhelavskaya, Irina
A1  - Vasile, Ruggero
T1  - A new population of ultra-relativistic electrons in the outer radiation zone
JF  - Journal of geophysical research : Space physics
N2  - Van Allen Probes measurements revealed the presence of the most unusual structures in the ultra-relativistic radiation belts. Detailed modeling, analysis of pitch angle distributions, analysis of the difference between relativistic and ultra-realistic electron evolution, along with theoretical studies of the scattering and wave growth, all indicate that electromagnetic ion cyclotron (EMIC) waves can produce a very efficient loss of the ultra-relativistic electrons in the heart of the radiation belts. Moreover, a detailed analysis of the profiles of phase space densities provides direct evidence for localized loss by EMIC waves. The evolution of multi-MeV fluxes shows dramatic and very sudden enhancements of electrons for selected storms. Analysis of phase space density profiles reveals that growing peaks at different values of the first invariant are formed at approximately the same radial distance from the Earth and show the sequential formation of the peaks from lower to higher energies, indicating that local energy diffusion is the dominant source of the acceleration from MeV to multi-MeV energies. Further simultaneous analysis of the background density and ultra-relativistic electron fluxes shows that the acceleration to multi-MeV energies only occurs when plasma density is significantly depleted outside of the plasmasphere, which is consistent with the modeling of acceleration due to chorus waves.
KW  - radiation belts
KW  - ultra-relativistic electrons
KW  - EMIC waves
KW  - modeling;
KW  - plasma density
KW  - chorus waves
Y1  - 2022
U6  - https://doi.org/10.1029/2021JA030214
SN  - 2169-9380
SN  - 2169-9402
VL  - 127
IS  - 5
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Scholz, Carolin
A1  - Voigt, Christian C.
T1  - Diet analysis of bats killed at wind turbines suggests large-scale losses of trophic interactions
JF  - Conservation science and practice
N2  - Agricultural practice has led to landscape simplification and biodiversity decline, yet recently, energy-producing infrastructures, such as wind turbines, have been added to these simplified agroecosystems, turning them into multi-functional energy-agroecosystems. Here, we studied the trophic interactions of bats killed at wind turbines using a DNA metabarcoding approach to shed light on how turbine-related bat fatalities may possibly affect local habitats. Specifically, we identified insect DNA in the stomachs of common noctule bats (Nyctalus noctula) killed by wind turbines in Germany to infer in which habitats these bats hunted. Common noctule bats consumed a wide variety of insects from different habitats, ranging from aquatic to terrestrial ecosystems (e.g., wetlands, farmland, forests, and grasslands). Agricultural and silvicultural pest insects made up about 20% of insect species consumed by the studied bats. Our study suggests that the potential damage of wind energy production goes beyond the loss of bats and the decline of bat populations. Bat fatalities at wind turbines may lead to the loss of trophic interactions and ecosystem services provided by bats, which may add to the functional simplification and impaired crop production, respectively, in multi-functional ecosystems.
KW  - bat fatalities
KW  - biodiversity decline
KW  - food web
KW  - green-green dilemma
KW  - renewable energy
KW  - wind energy production
KW  - wind energy-biodiversity conflict
Y1  - 2022
U6  - https://doi.org/10.1111/csp2.12744
SN  - 2578-4854
VL  - 4
IS  - 7
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Schildgen, Taylor F.
A1  - van der Beek, Peter A.
A1  - D'Arcy, Mitch
A1  - Roda-Boluda, Duna N.
A1  - Orr, Elizabeth N.
A1  - Wittmann, Hella
T1  - Quantifying drainage-divide migration from orographic rainfall over geologic timescales
BT  - Sierra de Aconquija, southern Central Andes
JF  - Earth & planetary science letters
N2  - Drainage-divide migration, controlled by rock-uplift and rainfall patterns, may play a major role in the geomorphic evolution of mountain ranges. 

However, divide-migration rates over geologic timescales have only been estimated by theoretical studies and remain empirically poorly constrained. 
Geomorphological evidence suggests that the Sierra de Aconquija, on the eastern side of the southern Central Andes, northwest Argentina, is undergoing active westward drainage-divide migration. The mountain range has been subjected to steep rock trajectories and pronounced orographic rainfall for the last several million years, presenting an ideal setting for using low-temperature thermochronometric data to explore its topographic evolution. 

We perform three-dimensional thermal-kinematic modeling of previously published thermochronometric data spanning the windward and leeward sides of the range to explore the most likely structural and topographic evolution of the range. 

We find that the data can be explained by scenarios involving drainage-divide migration alone, or by scenarios that also involve changes in the structures that have accommodated deformation through time. 
By combining new Be-10-derived catchment-average denudation rates with geomorphic constraints on probable fault activity, we conclude that the evolution of the range was likely dominated by west-vergent faulting on a high-angle reverse fault underlying the range, together with westward drainage-divide migration at a rate of several km per million years. 

Our findings place new constraints on the magnitudes and rates of drainage-divide migration in real landscapes, quantify the effects of orographic rainfall and erosion on the topographic evolution of a mountain range, and highlight the importance of considering drainage-divide migration when interpreting thermochronometer age patterns.
KW  - drainage-divide migration
KW  - landscape evolution
KW  - orographic rainfall
KW  - thermochronology
KW  - cosmogenic nuclides
KW  - Central Andes
Y1  - 2022
U6  - https://doi.org/10.1016/j.epsl.2021.117345
SN  - 0012-821X
SN  - 1385-013X
VL  - 579
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schifferle, Lukas
A1  - Lobanov, Sergey S.
T1  - Evolution of chemical bonding and spin-pairing energy in ferropericlase across Its spin transition
JF  - ACS Earth and Space Chemistry
N2  - The evolution of chemical bonding in ferropericlase, (Mg,Fe)O, with pressure may affect the physical and chemical properties of the Earth's lower mantle. Here, we report high-pressure optical absorption spectra of single-crystalline ferropericlase ((Mg0.87Fe0.13)O) up to 135 GPa. Combined with a re-evaluation of published partial fluorescence yield X-ray absorption spectroscopy data, we show that the covalency of the Fe-O bond increases with pressure, but the iron spin transition at 57-76.5 GPa reverses this trend. The qualitative crossover in chemical bonding suggests that the spin-pairing transition weakens the Fe-O bond in ferropericlase. We find, that the spin transition in ferropericlase is caused by both the increase of the ligand field-splitting energy and the decrease in the spin-pairing energy of high-spin Fe2+.
KW  - high-pressure
KW  - diamond anvil cell
KW  - covalency
KW  - bond strength
KW  - iron
KW  - spin
KW  - transition
Y1  - 2022
U6  - https://doi.org/10.1021/acsearthspacechem.2c00014
SN  - 2472-3452
VL  - 6
IS  - 3
SP  - 788
EP  - 799
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Sarrazin, Fanny J.
A1  - Kumar, Rohini
A1  - Basu, Nandita B.
A1  - Musolff, Andreas
A1  - Weber, Michael
A1  - Van Meter, Kimberly J.
A1  - Attinger, Sabine
T1  - Characterizing catchment-scale nitrogen legacies and constraining their uncertainties
JF  - Water resources research
N2  - Improving nitrogen (N) status in European water bodies is a pressing issue. N levels depend not only on current but also past N inputs to the landscape, that have accumulated through time in legacy stores (e.g., soil, groundwater). 
Catchment-scale N models, that are commonly used to investigate in-stream N levels, rarely examine the magnitude and dynamics of legacy components. 

This study aims to gain a better understanding of the long-term fate of the N inputs and its uncertainties, using a legacy-driven N model (ELEMeNT) in Germany's largest national river basin (Weser; 38,450 km(2)) over the period 1960-2015. 
We estimate the nine model parameters based on a progressive constraining strategy, to assess the value of different observational data sets. 
We demonstrate that beyond in-stream N loading, soil N content and in-stream N concentration allow to reduce the equifinality in model parameterizations. 
We find that more than 50% of the N surplus denitrifies (1480-2210 kg ha(-1)) and the stream export amounts to around 18% (410-640 kg ha(-1)), leaving behind as much as around 230-780 kg ha(-1) of N in the (soil) source zone and 10-105 kg ha(-1) in the subsurface. 

A sensitivity analysis reveals the importance of different factors affecting the residual uncertainties in simulated N legacies, namely hydrologic travel time, denitrification rates, a coefficient characterizing the protection of organic N in source zone and N surplus input. 

Our study calls for proper consideration of uncertainties in N legacy characterization, and discusses possible avenues to further reduce the equifinality in water quality modeling.
KW  - nitrogen legacies
KW  - water quality modeling
KW  - equifinality
KW  - parameter
KW  - estimation
KW  - sensitivity analysis
Y1  - 2022
U6  - https://doi.org/10.1029/2021WR031587
SN  - 0043-1397
SN  - 1944-7973
VL  - 58
IS  - 4
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Rolph, Rebecca
A1  - Overduin, Pier Paul
A1  - Ravens, Thomas
A1  - Lantuit, Hugues
A1  - Langer, Moritz
T1  - ArcticBeach v1.0
BT  - a physics-based parameterization of pan-Arctic coastline erosion
JF  - Frontiers in Earth Science
N2  - In the Arctic, air temperatures are increasing and sea ice is declining, resulting in larger waves and a longer open water season, all of which intensify the thaw and erosion of ice-rich coasts. Climate change has been shown to increase the rate of Arctic coastal erosion, causing problems for Arctic cultural heritage, existing industrial, military, and civil infrastructure, as well as changes in nearshore biogeochemistry. Numerical models that reproduce historical and project future Arctic erosion rates are necessary to understand how further climate change will affect these problems, and no such model yet exists to simulate the physics of erosion on a pan-Arctic scale. We have coupled a bathystrophic storm surge model to a simplified physical erosion model of a permafrost coastline. This Arctic erosion model, called ArcticBeach v1.0, is a first step toward a physical parameterization of Arctic shoreline erosion for larger-scale models. It is forced by wind speed and direction, wave period and height, sea surface temperature, all of which are masked during times of sea ice cover near the coastline. Model tuning requires observed historical retreat rates (at least one value), as well as rough nearshore bathymetry. These parameters are already available on a pan-Arctic scale. The model is validated at three study sites at 1) Drew Point (DP), Alaska, 2) Mamontovy Khayata (MK), Siberia, and 3) Veslebogen Cliffs, Svalbard. Simulated cumulative retreat rates for DP and MK respectively (169 and 170 m) over the time periods studied at each site (2007-2016, and 1995-2018) are found to the same order of magnitude as observed cumulative retreat (172 and 120 m). The rocky Veslebogen cliffs have small observed cumulative retreat rates (0.05 m over 2014-2016), and our model was also able to reproduce this same order of magnitude of retreat (0.08 m). Given the large differences in geomorphology between the study sites, this study provides a proof-of-concept that ArcticBeach v1.0 can be applied on very different permafrost coastlines. ArcticBeach v1.0 provides a promising starting point to project retreat of Arctic shorelines, or to evaluate historical retreat in places that have had few observations.
KW  - permafrost
KW  - erosion
KW  - modelling
KW  - arctic
KW  - climate change
Y1  - 2022
U6  - https://doi.org/10.3389/feart.2022.962208
SN  - 2296-6463
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Rodriguez, Victoria
A1  - Moskwa, Lisa-Marie
A1  - Oses, Romulo
A1  - Kühn, Peter
A1  - Riveras-Muñoz, Nicolás
A1  - Seguel, Oscar
A1  - Scholten, Thomas
A1  - Wagner, Dirk
T1  - Impact of climate and slope aspects on the composition of soil bacterial communities involved in pedogenetic processes along the chilean coastal cordillera
JF  - Microorganisms
N2  - Soil bacteria play a fundamental role in pedogenesis. However, knowledge about both the impact of climate and slope aspects on microbial communities and the consequences of these items in pedogenesis is lacking. Therefore, soil-bacterial communities from four sites and two different aspects along the climate gradient of the Chilean Coastal Cordillera were investigated. Using a combination of microbiological and physicochemical methods, soils that developed in arid, semi-arid, mediterranean, and humid climates were analyzed. Proteobacteria, Acidobacteria, Chloroflexi, Verrucomicrobia, and Planctomycetes were found to increase in abundance from arid to humid climates, while Actinobacteria and Gemmatimonadetes decreased along the transect. Bacterial-community structure varied with climate and aspect and was influenced by pH, bulk density, plant-available phosphorus, clay, and total organic-matter content. Higher bacterial specialization was found in arid and humid climates and on the south-facing slope and was likely promoted by stable microclimatic conditions. The presence of specialists was associated with ecosystem-functional traits, which shifted from pioneers that accumulated organic matter in arid climates to organic decomposers in humid climates. These findings provide new perspectives on how climate and slope aspects influence the composition and functional capabilities of bacteria, with most of these capabilities being involved in pedogenetic processes.
KW  - bacterial-community structure
KW  - bacterial diversity
KW  - climate gradient
KW  - slope aspect
KW  - Chilean Coastal Cordillera
KW  - soil formation
Y1  - 2022
U6  - https://doi.org/10.3390/microorganisms10050847
SN  - 2076-2607
VL  - 10
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Rodriguez Piceda, Constanza
A1  - Scheck-Wenderoth, Magdalena
A1  - Cacace, Mauro
A1  - Bott, Judith
A1  - Strecker, Manfred
T1  - Long-Term Lithospheric Strength and Upper-Plate Seismicity in the Southern Central Andes, 29 degrees-39 degrees S
JF  - Geochemistry, geophysics, geosystems
N2  - We examined the relationship between the mechanical strength of the lithosphere and the distribution of seismicity within the overriding continental plate of the southern Central Andes (SCA, 29 degrees-39 degrees S), where the oceanic Nazca Plate changes its subduction angle between 33 degrees S and 35 degrees S, from subhorizontal in the north (<5 degrees) to steep in the south (similar to 30 degrees). We computed the long-term lithospheric strength based on an existing 3D model describing variations in thickness, density, and temperature of the main geological units forming the lithosphere of the SCA and adjacent forearc and foreland regions. The comparison between our results and seismicity within the overriding plate (upper-plate seismicity) shows that most of the events occur within the modeled brittle domain of the lithosphere. The depth where the deformation mode switches from brittle frictional to thermally activated ductile creep provides a conservative lower bound to the seismogenic zone in the overriding plate of the study area. We also found that the majority of upper-plate earthquakes occurs within the realm of first-order contrasts in integrated strength (12.7-13.3 log Pam in the Andean orogen vs. 13.5-13.9 log Pam in the forearc and the foreland). Specific conditions characterize the mechanically strong northern foreland of the Andes, where seismicity is likely explained by the effects of slab steepening.
KW  - subduction zone
KW  - Andes
KW  - rheology
KW  - seismicity
KW  - flat-slab
Y1  - 2022
U6  - https://doi.org/10.1029/2021GC010171
SN  - 1525-2027
VL  - 23
IS  - 3
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Rodriguez Piceda, Constanza
A1  - Scheck-Wenderoth, Magdalena
A1  - Bott, Judith
A1  - Gomez Dacal, Maria Laura
A1  - Cacace, Mauro
A1  - Pons, Michael
A1  - Prezzi, Claudia
A1  - Strecker, Manfred
T1  - Controls of the Lithospheric Thermal Field of an Ocean-Continent Subduction Zone
BT  - the Southern Central Andes
JF  - Lithosphere / Geological Society of America
N2  - In an ocean-continent subduction zone, the assessment of the lithospheric thermal state is essential to determine the controls of the deformation within the upper plate and the dip angle of the subducting lithosphere. In this study, we evaluate the degree of influence of both the configuration of the upper plate (i.e., thickness and composition of the rock units) and variations of the subduction angle on the lithospheric thermal field of the southern Central Andes (29 degrees-39 degrees S). Here, the subduction angle increases from subhorizontal (5 degrees) north of 33 degrees S to steep (similar to 30 degrees) in the south. We derived the 3D temperature and heat flow distribution of the lithosphere in the southern Central Andes considering conversion of S wave tomography to temperatures together with steady-state conductive thermal modeling. We found that the orogen is overall warmer than the forearc and the foreland and that the lithosphere of the northern part of the foreland appears colder than its southern counterpart. Sedimentary blanketing and the thickness of the radiogenic crust exert the main control on the shallow thermal field (<50km depth). Specific conditions are present where the oceanic slab is relatively shallow (<85 km depth) and the radiogenic crust is thin. This configuration results in relatively colder temperatures compared to regions where the radiogenic crust is thick and the slab is steep. At depths >50km, the temperatures of the overriding plate are mainly controlled by the mantle heat input and the subduction angle. The thermal field of the upper plate likely preserves the flat subduction angle and influences the spatial distribution of shortening.
Y1  - 2022
U6  - https://doi.org/10.2113/2022/2237272
SN  - 1941-8264
SN  - 1947-4253
VL  - 2022
IS  - 1
PB  - GeoScienceWorld
CY  - McLean
ER  - 
TY  - JOUR
A1  - Riedl, Simon
A1  - Melnick, Daniel
A1  - Njue, Lucy
A1  - Sudo, Masafumi
A1  - Strecker, Manfred
T1  - Mid-Pleistocene to recent crustal extension in the inner graben of the Northern Kenya Rift
JF  - Geochemistry, geophysics, geosystems
N2  - Magmatic continental rifts often constitute nascent plate boundaries, yet long-term extension rates and transient rate changes associated with these early stages of continental breakup remain difficult to determine. Here, we derive a time-averaged minimum extension rate for the inner graben of the Northern Kenya Rift (NKR) of the East African Rift System for the last 0.5 m.y. We use the TanDEM-X science digital elevation model to evaluate fault-scarp geometries and determine fault throws across the volcano-tectonic axis of the inner graben of the NKR. Along rift-perpendicular profiles, amounts of cumulative extension are determined, and by integrating four new Ar-40/Ar-39 radiometric dates for the Silali volcano into the existing geochronology of the faulted volcanic units, time-averaged extension rates are calculated. This study reveals that in the inner graben of the NKR, the long-term extension rate based on mid-Pleistocene to recent brittle deformation has minimum values of 1.0-1.6 mm yr(-1), locally with values up to 2.0 mm yr(-1). A comparison with the decadal, geodetically determined extension rate reveals that at least 65% of the extension must be accommodated within a narrow, 20-km-wide zone of the inner rift. In light of virtually inactive border faults of the NKR, we show that extension is focused in the region of the active volcano-tectonic axis in the inner graben, thus highlighting the maturing of continental rifting in the NKR.
KW  - extensional tectonics
KW  - Kenya Rift
KW  - TanDEM-X DEM
KW  - DEM analysis
KW  - geochronology
KW  - normal faults
Y1  - 2022
U6  - https://doi.org/10.1029/2021GC010123
SN  - 1525-2027
VL  - 23
IS  - 3
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Ribacki, Enrico
A1  - Trumbull, Robert B.
A1  - Lopez De Luchi, Monica Graciela
A1  - Altenberger, Uwe
T1  - The chemical and B-Isotope composition of Tourmaline from intra-granitic Pegmatites in the Las Chacras-Potrerillos Batholith, Argentina
JF  - The Canadian mineralogist : journal of the Mineralogical Association of Canada
N2  - The Devonian Las Chacras-Potrerillos batholith comprises six nested monzonitic to granitic intrusions with metaluminous to weakly peraluminous composition and a Sr-Nd isotopic signature indicating a dominantly juvenile mantle-derived source. The chemically most evolved units in the southern batholith contain a large number of intra-granitic, pod-shaped tourmaline-bearing pegmatites. This study uses in situ chemical and boron isotopic analyses of tourmaline from nine of these pegmatites to discuss their relationship to the respective host intrusions and the implications of their B-isotope composition for the source and evolution of the magmas. The tourmalines reveal a diversity in element composition (e.g., FeO, MgO, TiO2, CaO, MnO, F) which distinguishes individual pegmatites from one another. However, all have a narrow 5 11 B range of -13.7 to -10.5%0 (n = 100) which indicates a relatively uniform magmatic system and similar temperature conditions during tourmaline crystallization. The average delta(11) B value of -11.7%0 is typical for S-type granites and is within the range reported for peraluminous granites. pegmatites, and metamorphic units of the Ordovician basement into which the Las Chacras-Potrerillos batholith intruded. The B-isotope evidence argues for a crustal boron source like that of the Ordovician basement, in contrast to the metaluminous to weakly peraluminous composition and juvenile initial Sr and Nd isotope ratios of the Las Chacras-Potrerillos batholith magmas. We propose that the boron was not derived from the magma source region but was incorporated from dehydration melting of elastic metasedimentary rocks higher up in the crustal column.
KW  - pegmatite
KW  - tourmaline
KW  - SIMS
KW  - B-isotopes
KW  - Las Chacras-Potrerillos
KW  - Sierra de San Luis
KW  - Argentina
Y1  - 2022
U6  - https://doi.org/10.3749/canmin.2100036
SN  - 0008-4476
SN  - 1499-1276
VL  - 60
IS  - 1
SP  - 49
EP  - 66
PB  - Association of Canada
CY  - Ottawa
ER  - 
TY  - JOUR
A1  - Rembe, Johannes
A1  - Sobel, Edward
A1  - Kley, Jonas
A1  - Terbishalieva, Baiansulu
A1  - Musiol, Antje
A1  - Chen, Jie
A1  - Zhou, Renjie
T1  - Geochronology, Geochemistry, and Geodynamic Implications of Permo-Triassic Back-Arc Basin Successions in the North Pamir, Central Asia
JF  - Lithosphere
N2  - The Permo-Triassic period marks the time interval between Hercynian (Variscan) orogenic events in the Tien Shan and the North Pamir, and the Cimmerian accretion of the Gondwana-derived Central and South Pamir to the southern margin of the Paleo-Asian continent. A well-preserved Permo-Triassic volcano-sedimentary sequence from the Chinese North Pamir yields important information on the geodynamic evolution of Asia’s pre-Cimmerian southern margin. The oldest volcanic rocks from that section are dated to the late Guadalupian epoch by a rhyolite and a dacitic dike that gave zircon U-Pb ages of ~260 Ma. Permian volcanism was largely pyroclastic and mafic to intermediate. Upsection, a massive ignimbritic crystal tuff in the Chinese Qimgan valley was dated to 244.1 +/- 1.1 Ma, a similar unit in the nearby Gez valley to 245 +/- 11 Ma, and an associated rhyolite to 233.4 +/- 1.1 Ma. Deposition of the locally ~200 m thick crystal tuff unit follows an unconformity and marks the onset of intense, mainly mafic to intermediate, calc-alkaline magmatic activity. Triassic volcanic activity in the North Pamir was coeval with the major phase of Cimmerian intrusive activity in the Karakul-Mazar arc-accretionary complex to the south, caused by northward subduction of the Paleo-Tethys. It also coincided with the emplacement of basanitic and carbonatitic dikes and a thermal event in the South Tien Shan, to the north of our study area. Evidence for arc-related magmatic activity in a back-arc position provides strong arguments for back-arc extension or transtension and basin formation. This puts the Qimgan succession in line with a more than 1000 km long realm of extensional Triassic back-arc basins known from the North Pamir in the Kyrgyz Altyn Darya valley (Myntekin formation), the North Pamir of Tajikistan and Afghanistan, and the Afghan Hindukush (Doab formation) and further west from the Paropamisus and Kopet Dag (Aghdarband, NE Iran).
Y1  - 2022
U6  - https://doi.org/10.2113/2022/7514691
SN  - 1947-4253
VL  - 2022
IS  - 1
PB  - GeoScienceWorld, Geological Society of America
CY  - Boulder, Colorado, USA
ER  - 
TY  - JOUR
A1  - Regmi, Shakil
A1  - Bookhagen, Bodo
T1  - The spatial pattern of extreme precipitation from 40 years of gauge data in the central Himalaya
JF  - Weather and climate extremes
N2  - The topography of the Himalaya exerts a substantial control on the spatial distribution of monsoonal rainfall, which is a vital water source for the regional economy and population. But the occurrence of short-lived and high-intensity precipitation results in socio-economic losses. This study relies on 40 years of daily data from 204 ground stations in Nepal to derive extreme precipitation thresholds, amounts, and days at the 95th percentile. We additionally determine the precipitation magnitude-frequency relation. We observe that extreme precipitation amounts follow an almost uniform band parallel to topographic contour lines in the southern Himalaya mountains in central and eastern Nepal but not in western Nepal. The relationship of extreme precipitation indices with topographic relief shows that extreme precipitation thresholds decrease with increasing elevation, but extreme precipitation days increase in higher elevation areas. Furthermore, stations above 1 km elevation exhibit a power-law relation in the rainfall magnitude-frequency framework. Stations at higher elevations generally have lower values of power-law exponents than low elevation areas. This suggests a fundamentally different behaviour of the rainfall distribution and an increased occurrence of extreme rainfall storms in the high elevation areas of Nepal.
KW  - Himalaya
KW  - Nepal
KW  - Indian summer monsoon
KW  - Precipitation
KW  - Extreme
KW  - precipitation
Y1  - 2022
U6  - https://doi.org/10.1016/j.wace.2022.100470
SN  - 2212-0947
VL  - 37
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Rasigraf, Olivia
A1  - Wagner, Dirk
T1  - Landslides
BT  - an emerging model for ecosystem and soil chronosequence research
JF  - Earth science reviews : the international geological journal bridging the gap between research articles and textbooks
N2  - Erosion by landslides is a common phenomenon in mountain regions around the globe, affecting all climatic zones. Landslides facilitate bedrock weathering, pedogenesis and ecological succession, being key drivers of biodiversity. Landslide chronosequences have long been used for studies of vegetation succession in initial ecosystems, but they further offer ideal model systems for studies of soil development and microbial community succession. In this review we synthesize the state of knowledge on the role of landslides in ecosystems, their influence on element cycles and interactions with biota. Further, we discuss feedback mechanisms between global warming, landslide activity and greenhouse gas emissions. In the view of increasing anthropogenic influence and climate change, soils are becoming a critical resource. Due to their ubiquity, landslide chronosequences have the potential to provide critical insights into soil development under different climates and thereby contribute to future soil restoration efforts.
KW  - Landslides
KW  - Greenhouse gas emissions
KW  - Landslide chronosequences
KW  - Soil
KW  - microbial community
KW  - Erosion
KW  - Biodiversity
KW  - Microbial processes
KW  - Climate
KW  - change
Y1  - 2022
U6  - https://doi.org/10.1016/j.earscirev.2022.104064
SN  - 0012-8252
SN  - 1872-6828
VL  - 231
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Ramachandran, Srikanthan
A1  - Rupakheti, Maheswar
A1  - Cherian, R.
A1  - Lawrence, Mark
T1  - Climate Benefits of Cleaner Energy Transitions in East and South Asia Through Black Carbon Reduction
JF  - Frontiers in environmental science
N2  - The state of air pollution has historically been tightly linked to how we produce and use energy. Air pollutant emissions over Asia are now changing rapidly due to cleaner energy transitions; however, magnitudes of benefits for climate and air quality remain poorly quantified. The associated risks involve adverse health impacts, reduced agricultural yields, reduced freshwater availability, contributions to climate change, and economic costs. We focus particularly on climate benefits of energy transitions by making first-time use of two decades of high quality observations of atmospheric loading of light-absorbing black carbon (BC) over Kanpur (South Asia) and Beijing (East Asia) and relating these observations to changing energy, emissions, and economic trends in India and China. Our analysis reveals that absorption aerosol optical depth (AAOD) due to BC has decreased substantially, by 40% over Kanpur and 60% over Beijing between 2001 and 2017, and thus became decoupled from regional economic growth. Furthermore, the resultant decrease in BC emissions and BC AAOD over Asia is regionally coherent and occurs primarily due to transitions into cleaner energies (both renewables and fossil fuels) and not due to the decrease in primary energy supply or decrease in use of fossil use and biofuels and waste. Model simulations show that BC aerosols alone contribute about half of the surface temperature change (warming) of the total forcing due to greenhouse gases, natural and internal variability, and aerosols, thus clearly revealing the climate benefits due to a reduction in BC emissions, which would significantly reduce global warming. However, this modeling study excludes responses from natural variability, circulation, and sea ice responses, which cause relatively strong temperature fluctuations that may mask signals from BC aerosols. Our findings show additional benefits for climate (beyond benefits of CO2 reduction) and for several other issues of sustainability over South and East Asia, provide motivation for ongoing cleaner energy production, and consumption transitions, especially when they are associated with reduced emissions of air pollutants. Such an analysis connecting the trends in energy transitions and aerosol absorption loading, unavailable so far, is crucial for simulating the aerosol climate impacts over Asia which is quite uncertain.
KW  - cleaner energy transitions
KW  - Asia
KW  - air pollution
KW  - black carbon
KW  - climate benefits
Y1  - 2022
U6  - https://doi.org/10.3389/fenvs.2022.842319
SN  - 2296-665X
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Radosavljevic, Boris
A1  - Lantuit, Hugues
A1  - Knoblauch, Christian
A1  - Couture, Nicole
A1  - Herzschuh, Ulrike
A1  - Fritz, Michael
T1  - Arctic nearshore sediment dynamics - an example from Herschel Island - Qikiqtaruk, Canada
JF  - Journal of marine science and engineering
N2  - Increasing arctic coastal erosion rates imply a greater release of sediments and organic matter into the coastal zone. With 213 sediment samples taken around Herschel Island-Qikiqtaruk, Canadian Beaufort Sea, we aimed to gain new insights on sediment dynamics and geochemical properties of a shallow arctic nearshore zone. Spatial characteristics of nearshore sediment texture (moderately to poorly sorted silt) are dictated by hydrodynamic processes, but ice-related processes also play a role. We determined organic matter (OM) distribution and inferred the origin and quality of organic carbon by C/N ratios and stable carbon isotopes delta C-13. The carbon content was higher offshore and in sheltered areas (mean: 1.0 wt.%., S.D.: 0.9) and the C/N ratios also showed a similar spatial pattern (mean: 11.1, S.D.: 3.1), while the delta C-13 (mean: -26.4 parts per thousand VPDB, S.D.: 0.4) distribution was more complex. We compared the geochemical parameters of our study with terrestrial and marine samples from other studies using a bootstrap approach. Sediments of the current study contained 6.5 times and 1.8 times less total organic carbon than undisturbed and disturbed terrestrial sediments, respectively. Therefore, degradation of OM and separation of carbon pools take place on land and continue in the nearshore zone, where OM is leached, mineralized, or transported beyond the study area.
KW  - permafrost
KW  - Arctic Ocean
KW  - stable carbon isotopes
KW  - nitrogen
KW  - sediment
KW  - chemistry
KW  - sediment dynamics
KW  - Beaufort Sea
KW  - grain size
Y1  - 2022
U6  - https://doi.org/10.3390/jmse10111589
SN  - 2077-1312
VL  - 10
IS  - 11
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Procyk, Roman
A1  - Lovejoy, Shaun
A1  - Hébert, Raphaёl
T1  - The fractional energy balance equation for climate projections through 2100
JF  - Earth system dynamics / European Geosciences Union
N2  - We produce climate projections through the 21st century using the fractional energy balance equation (FEBE): a generalization of the standard energy balance equation (EBE). The FEBE can be derived from Budyko-Sellers models or phenomenologically through the application of the scaling symmetry to energy storage processes, easily implemented by changing the integer order of the storage (derivative) term in the EBE to a fractional value. 
The FEBE is defined by three parameters: a fundamental shape parameter, a timescale and an amplitude, corresponding to, respectively, the scaling exponent h, the relaxation time tau and the equilibrium climate sensitivity (ECS). Two additional parameters were needed for the forcing: an aerosol recalibration factor alpha to account for the large aerosol uncertainty and a volcanic intermittency correction exponent upsilon. A Bayesian framework based on historical temperatures and natural and anthropogenic forcing series was used for parameter estimation. Significantly, the error model was not ad hoc but rather predicted by the model itself: the internal variability response to white noise internal forcing. 
The 90 % credible interval (CI) of the exponent and relaxation time were h = [0.33, 0.44] (median = 0.38) and tau = [2.4, 7.0] (median = 4.7) years compared to the usual EBE h = 1, and literature values of tau typically in the range 2-8 years. Aerosol forcings were too strong, requiring a decrease by an average factor alpha = [0.2, 1.0] (median = 0.6); the volcanic intermittency correction exponent was upsilon = [0.15, 0.41] (median = 0.28) compared to standard values alpha = upsilon = 1. The overpowered aerosols support a revision of the global modern (2005) aerosol forcing 90 % CI to a narrower range [ -1.0, -0.2] W m(-2). The key parameter ECS in comparison to IPCC AR5 (and to the CMIP6 MME), the 90 % CI range is reduced from [1.5, 4.5] K ([2.0, 5.5] K) to [1.6, 2.4] K ([1.5, 2.2] K), with median value lowered from 3.0 K (3.7 K) to 2.0 K (1.8 K) Similarly we found for the transient climate response (TCR), the 90 % CI range shrinks from [1.0, 2.5] K ([1.2, 2.8] K) to [1.2, 1.8] K ([1.1, 1.6] K) and the median estimate decreases from 1.8 K (2.0 K) to 1.5 K (1.4 K). As often seen in other observational-based studies, the FEBE values for climate sensitivities are therefore somewhat lower but still consistent with those in IPCC AR5 and the CMIP6 MME. <br /> Using these parameters, we made projections to 2100 using both the Representative Concentration Pathway (RCP) and Shared Socioeconomic Pathway (SSP) scenarios, and compared them to the corresponding CMIP5 and CMIP6 multi-model ensembles (MMEs). The FEBE historical reconstructions (1880-2020) closely follow observations, notably during the 1998-2014 slowdown ("hiatus"). We also reproduce the internal variability with the FEBE and statistically validate this against centennial-scale temperature observations. Overall, the FEBE projections were 10 %-15 % lower but due to their smaller uncertainties, their 90 % CIs lie completely within the GCM 90 % CIs. This agreement means that the FEBE validates the MME, and vice versa.
Y1  - 2022
U6  - https://doi.org/10.5194/esd-13-81-2022
SN  - 2190-4979
SN  - 2190-4987
VL  - 13
IS  - 1
SP  - 81
EP  - 107
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Porȩba, Tomasz
A1  - Racioppi, Stefano
A1  - Garbarino, Gaston
A1  - Morgenroth, Wolfgang
A1  - Mezouar, Mohamed
T1  - Investigating the structural symmetrization of CsI3 at high pressures through combined X-ray diffraction experiments and theoretical analysis
JF  - Inorganic chemistry
N2  - ABSTRACT: Structural evolution of cesium triiodide at high pressures has been revealed by synchrotron single-crystal X-ray diffraction. Cesium triiodide undergoes a first-order phase transition above 1.24(3) GPa from an orthorhombic to a trigonal system. This transition is coupled with severe reorganization of the polyiodide network from a layered to three-dimensional architecture. Quantum chemical calculations show that even though the two polymorphic phases are nearly isoenergetic under ambient conditions, the PV term is decisive in stabilizing the trigonal polymorph above the transition point. Phonon calculations using a non-local correlation functional that accounts for dispersion interactions confirm that this polymorph is dynamically unstable under ambient conditions. The high-pressure behavior of crystalline CsI3 can be correlated with other alkali metal trihalides, which undergo a similar sequence of structural changes upon load.
Y1  - 2022
U6  - https://doi.org/10.1021/acs.inorgchem.2c01690
SN  - 0020-1669
SN  - 1520-510X
VL  - 61
IS  - 28
SP  - 10977
EP  - 10985
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Platz, Anna
A1  - Weckmann, Ute
A1  - Pek, Josef
A1  - Kovacikova, Svetlana
A1  - Klanica, Radek
A1  - Mair, Johannes
A1  - Aleid, Basel
T1  - 3D imaging of the subsurface electrical resistivity structure in West Bohemia/Upper Palatinate covering mofettes and quaternary volcanic structures by using magnetotellurics
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - The region of West Bohemia and Upper Palatinate belongs to the West Bohemian Massif. The study area is situated at the junction of three different Variscan tectonic units and hosts the ENE-WSW trending Ohre Rift as well as many different fault systems. The entire region is characterized by ongoing magmatic processes in the intra-continental lithospheric mantle expressed by a series of phenomena, including e.g. the occurrence of repeated earthquake swarms and massive degassing of mantle derived CO2 in form of mineral springs and mofettes. Ongoing active tectonics is mainly manifested by Cenozoic volcanism represented by different Quaternary volcanic structures. All these phenomena make the Ohre Rift a unique target area for European intra-continental geo-scientific research. With magnetotelluric (MT) measurements we image the subsurface distribution of the electrical resistivity and map possible fluid pathways. Two-dimensional (2D) inversion results by Munoz et al. (2018) reveal a conductive channel in the vicinity of the earthquake swarm region that extends from the lower crust to the surface forming a pathway for fluids into the region of the mofettes. A second conductive channel is present in the south of their model; however, their 2D inversions allow ambiguous interpretations of this feature. Therefore, we conducted a large 3D MT field experiment extending the study area towards the south. The 3D inversion result matches well with the known geology imaging different fluid/magma reservoirs at crust-mantle depth and mapping possible fluid pathways from the reservoirs to the surface feeding known mofettes and spas. A comparison of 3D and 2D inversion results suggests that the 2D inversion results are considerably characterized by 3D and off-profile structures. In this context, the new results advocate for the swarm earthquakes being located in the resistive host rock surrounding the conductive channels; a finding in line with observations e.g. at the San Andreas Fault, California.
KW  - Magnetotellurics
KW  - Ohre Rift
KW  - Conductive channel
KW  - Fluid/magma reservoir
KW  - Earthquake swarm
Y1  - 2022
U6  - https://doi.org/10.1016/j.tecto.2022.229353
SN  - 0040-1951
SN  - 1879-3266
VL  - 833
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Peña, Carlos
A1  - Metzger, Sabrina
A1  - Heidbach, Oliver
A1  - Bedford, Jonathan
A1  - Bookhagen, Bodo
A1  - Moreno, Marcos
A1  - Oncken, Onno
A1  - Cotton, Fabrice
T1  - Role of poroelasticity during the early postseismic deformation of the 2010 Maule megathrust earthquake
JF  - Geophysical research letters
N2  - Megathrust earthquakes impose changes of differential stress and pore pressure in the lithosphere-asthenosphere system that are transiently relaxed during the postseismic period primarily due to afterslip, viscoelastic and poroelastic processes. 
Especially during the early postseismic phase, however, the relative contribution of these processes to the observed surface deformation is unclear. 
To investigate this, we use geodetic data collected in the first 48 days following the 2010 Maule earthquake and a poro-viscoelastic forward model combined with an afterslip inversion. 
This model approach fits the geodetic data 14% better than a pure elastic model. Particularly near the region of maximum coseismic slip, the predicted surface poroelastic uplift pattern explains well the observations. 
If poroelasticity is neglected, the spatial afterslip distribution is locally altered by up to +/- 40%. 
Moreover, we find that shallow crustal aftershocks mostly occur in regions of increased postseismic pore-pressure changes, indicating that both processes might be mechanically coupled.
KW  - Chilean subduction zone
KW  - poroelasticity
KW  - power-law rheology
KW  - afterslip inversion
KW  - InSAR
KW  - GNSS
Y1  - 2022
U6  - https://doi.org/10.1029/2022GL098144
SN  - 0094-8276
SN  - 1944-8007
VL  - 49
IS  - 9
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - Ou, Qi
A1  - Daout, Simon
A1  - Weiss, Jonathan R.
A1  - Shen, Lin
A1  - Lazecky, Milan
A1  - Wright, Tim J.
A1  - Parsons, Barry E.
T1  - Large-Scale interseismic strain mapping of the NE Tibetan Plateau from Sentinel-1 Interferometry
JF  - Journal of geophysical research : Solid earth
N2  - The launches of the Sentinel-1 synthetic aperture radar satellites in 2014 and 2016 started a new era of high-resolution velocity and strain rate mapping for the continents. However, multiple challenges exist in tying independently processed velocity data sets to a common reference frame and producing high-resolution strain rate fields. We analyze Sentinel-1 data acquired between 2014 and 2019 over the northeast Tibetan Plateau, and develop new methods to derive east and vertical velocities with similar to 100 m resolution and similar to 1 mm/yr accuracy across an area of 440,000 km(2). By implementing a new method of combining horizontal gradients of filtered east and interpolated north velocities, we derive the first similar to 1 km resolution strain rate field for this tectonically active region. The strain rate fields show concentrated shear strain along the Haiyuan and East Kunlun Faults, and local contractional strain on fault junctions, within the Qilianshan thrusts, and around the Longyangxia Reservoir. The Laohushan-Jingtai creeping section of the Haiyuan Fault is highlighted in our data set by extremely rapid strain rates. Strain across unknown portions of the Haiyuan Fault system, including shear on the eastern extension of the Dabanshan Fault and contraction at the western flank of the Quwushan, highlight unmapped tectonic structures. In addition to the uplift across most of the lowlands, the vertical velocities also contain climatic, hydrological or anthropogenic-related deformation signals. We demonstrate the enhanced view of large-scale active tectonic processes provided by high-resolution velocities and strain rates derived from Sentinel-1 data and highlight associated wide-ranging research applications.
KW  - Sentinel-1 InSAR
KW  - interseismic strain rate
KW  - creep and unmapped faults;
KW  - hydrological uplift and subsidence
KW  - tectonic geodesy
KW  - surface velocity
KW  - mapping
Y1  - 2022
U6  - https://doi.org/10.1029/2022JB024176
SN  - 2169-9313
SN  - 2169-9356
VL  - 127
IS  - 6
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Ortiz, Gustavo
A1  - Saez, Mauro
A1  - Alvarado, Patricia
A1  - Rivas, Carolina
A1  - García, Víctor Hugo
A1  - Alonso, Ricardo
A1  - Zullo, Fernando Morales
T1  - Seismotectonic characterization of the 1948 (M-W 6.9) Anta earthquake Santa  Barbara System, central Andes broken foreland of northwestern Argentina
JF  - Journal of South American earth sciences
N2  - The region of the Andean back-arc of northwestern Argentina has been struck by several magnitude >= 6 crustal earthquakes since the first historically recorded event in 1692. One of these events corresponds to the Anta earthquake on 25 August 1948, with epicenter in the Santa Barbara System causing three deaths and severe damage in Salta and Jujuy provinces with maximum Modified Mercalli seismic intensities (MMI) of IX. We collected and digitized analog seismograms of this earthquake from worldwide seismic observatories in order to perform first-motion analysis and modeling of long-period teleseismic P-waveforms. Our results indicate a simple seismic source of M0 = 2.85 x 1019 N m consistent with a moment magnitude Mw = 6.9. We have also tested for the focal depth determining a shallow source at 8 km with a reverse focal mechanism solution with a minor dextral strike-slip component (strike 20 degrees, dip 30 degrees, rake 120 degrees) from the best fit of waveforms. Using magnitude size empirical relationships, the comparison of the obtained Mw 6.9 magnitude value and the ca. 10,000 km2 area of MMI >= IX from our seismic intensity map, which was obtained from newspaper and many historical reports, indicates a rupture length of 42 +/- 8 km for the Anta earthquake. We show our results in a 3D geological model around the epicentral area, which integrates modern seismicity, geological data, and information of a previously studied east-west cross section located a few kilometers south of the 1948 epicenter. The integration of all available information provides evidence of the re-activation of the Pie de la Sierra del Gallo fault during the 1948 Mw 6.9 shallow earthquake; this thrust fault bounds the Santa Barbara System along its western foothill.
KW  - Active tectonics
KW  - Analog historical seismograms
KW  - Andean back-arc;
KW  - Thick-skinned tectonics
KW  - Central Andes
Y1  - 2022
U6  - https://doi.org/10.1016/j.jsames.2022.103822
SN  - 0895-9811
SN  - 1873-0647
VL  - 116
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Nomosatryo, Sulung
A1  - Tjallingii, Rik
A1  - Henny, Cynthia
A1  - Ridwansyah, Iwan
A1  - Wagner, Dirk
A1  - Tomás, Sara
A1  - Kallmeyer, Jens
T1  - Surface sediment composition and depositional environments in tropical Lake Sentani, Papua Province, Indonesia
JF  - Journal of Paleolimnology
N2  - Tropical Lake Sentani in the Indonesian Province Papua consists of four separate basins and is surrounded by a catchment with a very diverse geology. We characterized the surface sediment (upper 5 cm) of the lake's four sub-basins based on multivariate statistical analyses (principal component analysis, hierarchical clustering) of major element compositions obtained by X-ray fluorescence scanning. Three types of sediment are identified based on distinct compositional differences between rivers, shallow/proximal and deep/distal lake sediments. The different sediment types are mainly characterized by the correlation of elements associated with redox processes (S, Mn, Fe), carbonates (Ca), and detrital input (Ti, Al, Si, K) derived by river discharge. The relatively coarse-grained river sediments mainly derive form the mafic catchment geology and contribution of the limestone catchment geology is only limited. Correlation of redox sensitive and detrital elements are used to reveal oxidation conditions, and indicate oxic conditions in river samples and reducing conditions for lake sediments. Organic carbon (TOC) generally correlates with redox sensitive elements, although a correlation between TOC and individual elements change strongly between the three sediment types. Pyrite is the quantitatively dominant reduced sulfur mineral, monosulfides only reach appreciable concentrations in samples from rivers draining mafic and ultramafic catchments. Our study shows large spatial heterogeneity within the lake's sub-basins that is mainly caused by catchment geology and topography, river runoff as well as the bathymetry and the depth of the oxycline. We show that knowledge about lateral heterogeneity is crucial for understanding the geochemical and sedimentological variations recorded by these sediments. The highly variable conditions make Lake Sentani a natural laboratory, with its different sub-basins representing different depositional environments under identical tropical climate conditions.
KW  - Tropical lake
KW  - Lacustrine sediment
KW  - XRF analysis
KW  - Multivariate
KW  - statistics
Y1  - 2022
U6  - https://doi.org/10.1007/s10933-022-00259-4
SN  - 0921-2728
SN  - 1573-0417
PB  - Springer
CY  - Dordrecht
ER  -