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  - 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  - 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 A.
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  - 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  - 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  - 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  - 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  - 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 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  - 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  - 
TY  - JOUR
A1  - Nievas, Cecilia
A1  - Pilz, Marco
A1  - Prehn, Karsten
A1  - Schorlemmer, Danijel
A1  - Weatherill, Graeme
A1  - Cotton, Fabrice
T1  - Calculating earthquake damage building by building
BT  - the case of the city of Cologne, Germany
JF  - Bulletin of earthquake engineering : official publication of the European Association for Earthquake Engineering
N2  - The creation of building exposure models for seismic risk assessment is frequently challenging due to the lack of availability of detailed information on building structures. Different strategies have been developed in recent years to overcome this, including the use of census data, remote sensing imagery and volunteered graphic information (VGI). This paper presents the development of a building-by-building exposure model based exclusively on openly available datasets, including both VGI and census statistics, which are defined at different levels of spatial resolution and for different moments in time. The initial model stemming purely from building-level data is enriched with statistics aggregated at the neighbourhood and city level by means of a Monte Carlo simulation that enables the generation of full realisations of damage estimates when using the exposure model in the context of an earthquake scenario calculation. Though applicable to any other region of interest where analogous datasets are available, the workflow and approach followed are explained by focusing on the case of the German city of Cologne, for which a scenario earthquake is defined and the potential damage is calculated. The resulting exposure model and damage estimates are presented, and it is shown that the latter are broadly consistent with damage data from the 1978 Albstadt earthquake, notwithstanding the differences in the scenario. Through this real-world application we demonstrate the potential of VGI and open data to be used for exposure modelling for natural risk assessment, when combined with suitable knowledge on building fragility and accounting for the inherent uncertainties.
KW  - Building exposure modelling
KW  - Seismic damage assessment
KW  - Scenario
KW  - earthquake
KW  - Seismic risk
KW  - Cologne
Y1  - 2022
U6  - https://doi.org/10.1007/s10518-021-01303-w
SN  - 1570-761X
SN  - 1573-1456
VL  - 20
IS  - 3
SP  - 1519
EP  - 1565
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Neuharth, Derek
A1  - Brune, Sascha
A1  - Wrona, Thilo
A1  - Glerum, Anne
A1  - Braun, Jean
A1  - Yuan, Xiaoping
T1  - Evolution of rift systems and their fault networks in response to surface processes
JF  - Tectonics
N2  - Continental rifting is responsible for the generation of major sedimentary basins, both during rift inception and during the formation of rifted continental margins. Geophysical and field studies revealed that rifts feature complex networks of normal faults but the factors controlling fault network properties and their evolution are still matter of debate. Here, we employ high-resolution 2D geodynamic models (ASPECT) including two-way coupling to a surface processes (SP) code (FastScape) to conduct 12 models of major rift types that are exposed to various degrees of erosion and sedimentation. We further present a novel quantitative fault analysis toolbox (Fatbox), which allows us to isolate fault growth patterns, the number of faults, and their length and displacement throughout rift history. Our analysis reveals that rift fault networks may evolve through five major phases: (a) distributed deformation and coalescence, (b) fault system growth, (c) fault system decline and basinward localization, (d) rift migration, and (e) breakup. These phases can be correlated to distinct rifted margin domains. Models of asymmetric rifting suggest rift migration is facilitated through both ductile and brittle deformation within a weak exhumation channel that rotates subhorizontally and remains active at low angles. In sedimentation-starved settings, this channel satisfies the conditions for serpentinization. We find that SP are not only able to enhance strain localization and to increase fault longevity but that they also reduce the total length of the fault system, prolong rift phases and delay continental breakup.
KW  - rifts
KW  - fault network
KW  - surface processes
KW  - geodynamics
Y1  - 2022
U6  - https://doi.org/10.1029/2021TC007166
SN  - 0278-7407
SN  - 1944-9194
VL  - 41
IS  - 3
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Nagakura, Toshiki
A1  - Schubert, Florian
A1  - Wagner, Dirk
A1  - Kallmeyer, Jens
T1  - Biological sulfate reduction in deep subseafloor sediment of Guaymas Basin
JF  - Frontiers in microbiology
N2  - Sulfate reduction is the quantitatively most important process to degrade organic matter in anoxic marine sediment and has been studied intensively in a variety of settings. Guaymas Basin, a young marginal ocean basin, offers the unique opportunity to study sulfate reduction in an environment characterized by organic-rich sediment, high sedimentation rates, and high geothermal gradients (100-958 degrees C km(-1)). We measured sulfate reduction rates (SRR) in samples taken during the International Ocean Discovery Program (IODP) Expedition 385 using incubation experiments with radiolabeled (SO42-)-S-35 carried out at in situ pressure and temperature. The highest SRR (387 nmol cm(-3) d(-1)) was recorded in near-surface sediments from Site U1548C, which had the steepest geothermal gradient (958 degrees C km(-1)). At this site, SRR were generally over an order of magnitude higher than at similar depths at other sites (e.g., 387-157 nmol cm(-3) d(-1) at 1.9 mbsf from Site U1548C vs. 46-1.0 nmol cm(-3) d(-1) at 2.1 mbsf from Site U1552B). Site U1546D is characterized by a sill intrusion, but it had already reached thermal equilibrium and SRR were in the same range as nearby Site U1545C, which is minimally affected by sills. The wide temperature range observed at each drill site suggests major shifts in microbial community composition with very different temperature optima but awaits confirmation by molecular biological analyses. At the transition between the mesophilic and thermophilic range around 40 degrees C-60 degrees C, sulfate-reducing activity appears to be decreased, particularly in more oligotrophic settings, but shows a slight recovery at higher temperatures.
KW  - sulfate reduction
KW  - subsurface life
KW  - deep biosphere
KW  - thermophiles;
KW  - Guaymas Basin
Y1  - 2022
U6  - https://doi.org/10.3389/fmicb.2022.845250
SN  - 1664-302X
VL  - 13
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Mukherjee, Shreya
A1  - Adhikari, Avishek
A1  - Nicoli, Gautier
A1  - Vadlamani, Ravikant
T1  - Neoarchean (similar to 2.73-2.70 Ga) accretionary history of the eastern Dharwar Craton, India
BT  - Lu-Hf and Sm-Nd garnet geochronologic constraints from the Karimnagar granulite-facies supracrustal enclaves
JF  - Precambrian research
N2  - Cratonic mid-crustal plutons may contain supracrustal enclaves that preserve evidence of an earlier growth history. The Eastern Dharwar craton records Neoarchean two-stage accretionary sequential growth (2.70 and 2.55 Ga) and a chronology of their enclaves could refine orogenic models. To test whether the metamorphic history of their enclaves was related to any of these stages, phase equilibria modelling and combined Lu-Hf and Sm-Nd geochronology on garnet were conducted on metapsammite, now preserved as garnet-orthopyroxene-cordierite gneiss. Phase equilibria modelling indicates peak metamorphic conditions, similar to 850 degrees C and similar to 8.5 kbar (M1a), were followed by near isothermal decompression to 5-6 kbar (M1b) and isobaric cooling to similar to 800 degrees C (M1c). The thermobaric gradient related to peak metamorphic conditions, similar to 30 degrees C kbar(-1), is typical of collisional orogens. Regression of the whole-rock and garnet, for sample S17b, yield Lu-Hf isochron ages of 2733 +/- 29 Ma, and for sample S18, 2724 +/- 13 Ma. A Lu-Hf weighted mean age for the porphyroblastic garnet suggests growth at 2725.5 +/- 11.9 Ma during the M1a-M1b stages. In contrast, the whole-rock sample S17b and the garnet fractions yield a Sm-Nd isochron age of 2696 +/- 10 Ma. From sample S18 the whole rock, garnet fractions, and orthopyroxene yield an isochron age of 2683 +/- 15 Ma. The garnet Sm-Nd weighted mean age at 2692.0 +/- 8.3 Ma constrains the M1b-M1c stages. We suggest that the protoliths to these supracrustal enclaves were deposited in an arc tectonic setting and underwent thickening followed by heating during peeled-back lithospheric convergence. Therefore, the earliest of the craton-forming accretionary stages is preserved as the similar to 2.73 Ga granulite-facies enclaves, marginally older than the 2.70-2.65 Ga cratonic greenstone volcanism. Tectonic exhumation of these mid-crustal granulite enclaves was in response to the late-Proterozoic (similar to 1.7 Ga) Bhopalpatnam orogeny.
KW  - Eastern Dharwar craton
KW  - Granulite enclaves
KW  - Garnet-orthopyroxene-cordierite gneiss
KW  - Lu-Hf
KW  - Sm-Nd
KW  - Geochronology
Y1  - 2022
U6  - https://doi.org/10.1016/j.precamres.2022.106657
SN  - 0301-9268
VL  - 375
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mitzscherling, Julia
A1  - MacLean, Joana
A1  - Lipus, Daniel
A1  - Bartholomäus, Alexander
A1  - Mangelsdorf, Kai
A1  - Lipski, André
A1  - Roddatis, Vladimir
A1  - Liebner, Susanne
A1  - Wagner, Dirk
T1  - Nocardioides alcanivorans sp. nov., a novel hexadecane-degrading species isolated from plastic waste
JF  - International journal of systematic and evolutionary microbiology
N2  - Strain NGK65(T), a novel hexadecane degrading, non-motile, Gram-positive, rod-to-coccus shaped, aerobic bacterium, was isolated from plastic polluted soil sampled at a landfill. 
Strain NGK65(T) hydrolysed casein, gelatin, urea and was catalase-positive. It optimally grew at 28 degrees C. in 0-1% NaCl and at pH 7.5-8.0. Glycerol, D-glucose, arbutin, aesculin, salicin, potassium 5-ketogluconate. sucrose, acetate, pyruvate and hexadecane were used as sole carbon sources. 
The predominant membrane fatty acids were iso-C-16:0 followed by iso-C(17:)0 and C-18:1 omega 9c. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and hydroxyphosphatidylinositol. 
The cell-wall peptidoglycan type was A3 gamma, with LL-diaminopimelic acid and glycine as the diagnostic amino acids. MK 8 (H-4) was the predominant menaquinone. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NGK65(T) belongs to the genus Nocardioides (phylum Actinobacteria). appearing most closely related to Nocardioides daejeonensis MJ31(T) (98.6%) and Nocardioides dubius KSL-104(T) (98.3%). 
The genomic DNA G+C content of strain NGK65(T) was 68.2%. 
Strain NGK65(T) and the type strains of species involved in the analysis had average nucleotide identity values of 78.3-71.9% as well as digital DNA-DNA hybridization values between 22.5 and 19.7%, which clearly indicated that the isolate represents a novel species within the genus Nocardioides. 
Based on phenotypic and molecular characterization, strain NGK65(T) can clearly be differentiated from its phylogenetic neighbours to establish a novel species, for which the name Nocardioides alcanivorans sp. nov. is proposed. 
The type strain is NGK65(T) (=DSM 113112(T)=NCCB 100846(T)).
KW  - Nocardioides alcanivorans
KW  - hexadecane
KW  - plastic degradation
KW  - terrestrial
KW  - plastisphere
KW  - bacteria
Y1  - 2022
U6  - https://doi.org/10.1099/ijsem.0.005319
SN  - 1466-5026
SN  - 1466-5034
VL  - 72
IS  - 4
PB  - Microbiology Society
CY  - London
ER  - 
TY  - JOUR
A1  - Melchert, Jan Olaf
A1  - Wischhöfer, Philipp
A1  - Knoblauch, Christian
A1  - Eckhardt, Tim
A1  - Liebner, Susanne
A1  - Rethemeyer, Janet
T1  - Sources of CO2 Produced in Freshly Thawed Pleistocene-Age Yedoma Permafrost
JF  - Frontiers in Earth Science
N2  - The release of greenhouse gases from the large organic carbon stock in permafrost deposits in the circumarctic regions may accelerate global warming upon thaw. The extent of this positive climate feedback is thought to be largely controlled by the microbial degradability of the organic matter preserved in these sediments. In addition, weathering and oxidation processes may release inorganic carbon preserved in permafrost sediments as CO2, which is generally not accounted for. We used C-13 and C-14 analysis and isotopic mass balances to differentiate and quantify organic and inorganic carbon released as CO2 in the field from an active retrogressive thaw slump of Pleistocene-age Yedoma and during a 1.5-years incubation experiment. The results reveal that the dominant source of the CO2 released from freshly thawed Yedoma exposed as thaw mound is Pleistocene-age organic matter (48-80%) and to a lesser extent modern organic substrate (3-34%). A significant portion of the CO2 originated from inorganic carbon in the Yedoma (17-26%). The mixing of young, active layer material with Yedoma at a site on the slump floor led to the preferential mineralization of this young organic carbon source. Admixtures of younger organic substrates in the Yedoma thaw mound were small and thus rapidly consumed as shown by lower contributions to the CO2 produced during few weeks of aerobic incubation at 4 degrees C corresponding to approximately one thaw season. Future CO2 fluxes from the freshly thawed Yedoma will contain higher proportions of ancient inorganic (22%) and organic carbon (61-78%) as suggested by the results at the end, after 1.5 years of incubation. The increasing contribution of inorganic carbon during the incubation is favored by the accumulation of organic acids from microbial organic matter degradation resulting in lower pH values and, in consequence, in inorganic carbon dissolution. Because part of the inorganic carbon pool is assumed to be of pedogenic origin, these emissions would ultimately not alter carbon budgets. The results of this study highlight the preferential degradation of younger organic substrates in freshly thawed Yedoma, if available, and a substantial release of CO2 from inorganic sources.
KW  - yedoma ice complex
KW  - permafost
KW  - carbon cycle
KW  - climat change
KW  - thermokarst
KW  - radiocarbon
KW  - greenhouse gas
Y1  - 2022
U6  - https://doi.org/10.3389/feart.2021.737237
SN  - 2296-6463
VL  - 9
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Mar, Kathleen A.
A1  - Unger, Charlotte
A1  - Walderdorff, Ludmila
A1  - Butler, Tim
T1  - Beyond CO2 equivalence
BT  - The impacts of methane on climate, ecosystems, and health
JF  - Environmental science & policy
N2  - In this article we review the physical and chemical properties of methane (CH4) relevant to impacts on climate, ecosystems, and air pollution, and examine the extent to which this is reflected in climate and air pollution governance. Although CH4 is governed under the UNFCCC climate regime, its treatment there is limited to the ways in which it acts as a "CO2 equivalent" climate forcer on a 100-year time frame. The UNFCCC framework neglects the impacts that CH4 has on near-term climate, as well its impacts on human health and ecosystems, which are primarily mediated by methane's role as a precursor to tropospheric ozone. Frameworks for air quality governance generally address tropospheric ozone as a pollutant, but do not regulate CH4 itself. Methane's climate and air quality impacts, together with its alarming rise in atmospheric concentrations in recent years, make it clear that mitigation of CH4 emissions needs to be accelerated globally. We examine challenges and opportunities for further progress on CH4 mitigation within the international governance landscapes for climate change and air pollution.
KW  - Methane
KW  - Climate governance
KW  - Air pollution
KW  - International policy
KW  - Short-lived climate pollutants
KW  - Global warming potential
Y1  - 2022
U6  - https://doi.org/10.1016/j.envsci.2022.03.027
SN  - 1462-9011
SN  - 1873-6416
VL  - 134
SP  - 127
EP  - 136
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Macdonald, Elena
A1  - Merz, Bruno
A1  - Guse, Björn
A1  - Wietzke, Luzie
A1  - Ullrich, Sophie
A1  - Kemter, Matthias
A1  - Ahrens, Bodo
A1  - Vorogushyn, Sergiy
T1  - Event and catchment controls of heavy tail behavior of floods
JF  - Water resources research
N2  - In some catchments, the distribution of annual maximum streamflow shows heavy tail behavior, meaning the occurrence probability of extreme events is higher than if the upper tail decayed exponentially. Neglecting heavy tail behavior can lead to an underestimation of the likelihood of extreme floods and the associated risk. Partly contradictory results regarding the controls of heavy tail behavior exist in the literature and the knowledge is still very dispersed and limited. To better understand the drivers, we analyze the upper tail behavior and its controls for 480 catchments in Germany and Austria over a period of more than 50 years. The catchments span from quickly reacting mountain catchments to large lowland catchments, allowing for general conclusions. We compile a wide range of event and catchment characteristics and investigate their association with an indicator of the tail heaviness of flood distributions, namely the shape parameter of the GEV distribution. Following univariate analyses of these characteristics, along with an evaluation of different aggregations of event characteristics, multiple linear regression models, as well as random forests, are constructed. A novel slope indicator, which represents the relation between the return period of flood peaks and event characteristics, captures the controls of heavy tails best. Variables describing the catchment response are found to dominate the heavy tail behavior, followed by event precipitation, flood seasonality, and catchment size. The pre-event moisture state in a catchment has no relevant impact on the tail heaviness even though it does influence flood magnitudes.
KW  - heavy tail behavior
KW  - floods
KW  - event characteristics
KW  - catchment
KW  - characteristics
KW  - catchment response
Y1  - 2022
U6  - https://doi.org/10.1029/2021WR031260
SN  - 0043-1397
SN  - 1944-7973
VL  - 58
IS  - 6
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Lilienkamp, Henning
A1  - von Specht, Sebastian
A1  - Weatherill, Graeme
A1  - Caire, Giuseppe
A1  - Cotton, Fabrice
T1  - Ground-Motion modeling as an image processing task
BT  - introducing a neural network based, fully data-driven, and nonergodic
JF  - Bulletin of the Seismological Society of America
N2  - We construct and examine the prototype of a deep learning-based ground-motion model (GMM) that is both fully data driven and nonergodic. We formulate ground-motion modeling as an image processing task, in which a specific type of neural network, the U-Net, relates continuous, horizontal maps of earthquake predictive parameters to sparse observations of a ground-motion intensity measure (IM). The processing of map-shaped data allows the natural incorporation of absolute earthquake source and observation site coordinates, and is, therefore, well suited to include site-, source-, and path-specific amplification effects in a nonergodic GMM. Data-driven interpolation of the IM between observation points is an inherent feature of the U-Net and requires no a priori assumptions. We evaluate our model using both a synthetic dataset and a subset of observations from the KiK-net strong motion network in the Kanto basin in Japan. We find that the U-Net model is capable of learning the magnitude???distance scaling, as well as site-, source-, and path-specific amplification effects from a strong motion dataset. The interpolation scheme is evaluated using a fivefold cross validation and is found to provide on average unbiased predictions. The magnitude???distance scaling as well as the site amplification of response spectral acceleration at a period of 1 s obtained for the Kanto basin are comparable to previous regional studies.
Y1  - 2022
U6  - https://doi.org/10.1785/0120220008
SN  - 0037-1106
SN  - 1943-3573
VL  - 112
IS  - 3
SP  - 1565
EP  - 1582
PB  - Seismological Society of America
CY  - Albany
ER  - 
TY  - JOUR
A1  - Li, Zhen
A1  - Spangenberg, Erik
A1  - Schicks, Judith Maria
A1  - Kempka, Thomas
T1  - Numerical simulation of hydrate formation in the LArge-Scale Reservoir Simulator (LARS)
JF  - Energies : open-access journal of related scientific research, technology development and studies in policy and management
N2  - The LArge-scale Reservoir Simulator (LARS) has been previously developed to study hydrate dissociation in hydrate-bearing systems under in-situ conditions. In the present study, a numerical framework of equations of state describing hydrate formation at equilibrium conditions has been elaborated and integrated with a numerical flow and transport simulator to investigate a multi-stage hydrate formation experiment undertaken in LARS. A verification of the implemented modeling framework has been carried out by benchmarking it against another established numerical code. Three-dimensional (3D) model calibration has been performed based on laboratory data available from temperature sensors, fluid sampling, and electrical resistivity tomography. The simulation results demonstrate that temperature profiles, spatial hydrate distribution, and bulk hydrate saturation are consistent with the observations. Furthermore, our numerical framework can be applied to calibrate geophysical measurements, optimize post-processing workflows for monitoring data, improve the design of hydrate formation experiments, and investigate the temporal evolution of sub-permafrost methane hydrate reservoirs.
KW  - methane hydrate
KW  - temperature sensor
KW  - electrical resistivity tomography
KW  - hydrate formation
KW  - numerical simulation
Y1  - 2022
U6  - https://doi.org/10.3390/en15061974
SN  - 1996-1073
VL  - 15
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Li, Zhen
A1  - Spangenberg, Erik
A1  - Schicks, Judith Maria
A1  - Kempka, Thomas
T1  - Numerical Simulation of Coastal Sub-Permafrost Gas Hydrate Formation in the Mackenzie Delta, Canadian Arctic
JF  - Energies
N2  - The Mackenzie Delta (MD) is a permafrost-bearing region along the coasts of the Canadian Arctic which exhibits high sub-permafrost gas hydrate (GH) reserves. The GH occurring at the Mallik site in the MD is dominated by thermogenic methane (CH4), which migrated from deep conventional hydrocarbon reservoirs, very likely through the present fault systems. Therefore, it is assumed that fluid flow transports dissolved CH4 upward and out of the deeper overpressurized reservoirs via the existing polygonal fault system and then forms the GH accumulations in the Kugmallit-Mackenzie Bay Sequences. We investigate the feasibility of this mechanism with a thermo-hydraulic-chemical numerical model, representing a cross section of the Mallik site. We present the first simulations that consider permafrost formation and thawing, as well as the formation of GH accumulations sourced from the upward migrating CH4-rich formation fluid. The simulation results show that temperature distribution, as well as the thickness and base of the ice-bearing permafrost are consistent with corresponding field observations. The primary driver for the spatial GH distribution is the permeability of the host sediments. Thus, the hypothesis on GH formation by dissolved CH4 originating from deeper geological reservoirs is successfully validated. Furthermore, our results demonstrate that the permafrost has been substantially heated to 0.8-1.3 degrees C, triggered by the global temperature increase of about 0.44 degrees C and further enhanced by the Arctic Amplification effect at the Mallik site from the early 1970s to the mid-2000s.
KW  - gas hydrate
KW  - permafrost
KW  - methane
KW  - faults
KW  - climate change
KW  - Mallik
KW  - numerical simulations
Y1  - 2022
U6  - https://doi.org/10.3390/en15144986
SN  - 1996-1073
VL  - 15
IS  - 14
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Lescesen, Igor
A1  - Sraj, Mojca
A1  - Basarin, Biljana
A1  - Pavic, Dragoslav
A1  - Mesaros, Minucer
A1  - Mudelsee, Manfred
T1  - Regional flood frequency analysis of the sava river in south-eastern Europe
JF  - Sustainability
N2  - Regional flood frequency analysis (RFFA) is a powerful method for interrogating hydrological series since it combines observational time series from several sites within a region to estimate risk-relevant statistical parameters with higher accuracy than from single-site series. Since RFFA extreme value estimates depend on the shape of the selected distribution of the data-generating stochastic process, there is need for a suitable goodness-of-distributional-fit measure in order to optimally utilize given data. Here we present a novel, least-squares-based measure to select the optimal fit from a set of five distributions, namely Generalized Extreme Value (GEV), Generalized Logistic, Gumbel, Log-Normal Type III and Log-Pearson Type III. The fit metric is applied to annual maximum discharge series from six hydrological stations along the Sava River in South-eastern Europe, spanning the years 1961 to 2020. Results reveal that (1) the Sava River basin can be assessed as hydrologically homogeneous and (2) the GEV distribution provides typically the best fit. We offer hydrological-meteorological insights into the differences among the six stations. For the period studied, almost all stations exhibit statistically insignificant trends, which renders the conclusions about flood risk as relevant for hydrological sciences and the design of regional flood protection infrastructure.
KW  - discharge time series
KW  - flood risk analysis
KW  - Generalized Extreme Value distribution
KW  - L-moments estimation
KW  - regional flood frequency analysis
KW  - Sava River
Y1  - 2022
U6  - https://doi.org/10.3390/su14159282
SN  - 2071-1050
VL  - 14
IS  - 15
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Landis, D. A.
A1  - Saikin, Anthony
A1  - Zhelavskaya, Irina
A1  - Drozdov, Alexander
A1  - Aseev, Nikita
A1  - Shprits, Yuri Y.
A1  - Pfitzer, Maximilian F.
A1  - Smirnov, Artem G.
T1  - NARX Neural Network Derivations of the Outer Boundary Radiation Belt Electron Flux
JF  - Space Weather: the international journal of research and applications
N2  - We present two new empirical models of radiation belt electron flux at geostationary orbit. GOES-15 measurements of 0.8 MeV electrons were used to train a Nonlinear Autoregressive with Exogenous input (NARX) neural network for both modeling GOES-15 flux values and an upper boundary condition scaling factor (BF). The GOES-15 flux model utilizes an input and feedback delay of 2 and 2 time steps (i.e., 5 min time steps) with the most efficient number of hidden layers set to 10. Magnetic local time, Dst, Kp, solar wind dynamic pressure, AE, and solar wind velocity were found to perform as predicative indicators of GOES-15 flux and therefore were used as the exogenous inputs. The NARX-derived upper boundary condition scaling factor was used in conjunction with the Versatile Electron Radiation Belt (VERB) code to produce reconstructions of the radiation belts during the period of July-November 1990, independent of in-situ observations. Here, Kp was chosen as the sole exogenous input to be more compatible with the VERB code. This Combined Release and Radiation Effects Satellite-era reconstruction showcases the potential to use these neural network-derived boundary conditions as a method of hindcasting the historical radiation belts. This study serves as a companion paper to another recently published study on reconstructing the radiation belts during Solar Cycles 17-24 (Saikin et al., 2021, ), for which the results featured in this paper were used.
KW  - radiation belts
KW  - forecasting (1922, 4315, 7924, 7964)
KW  - machine learning (0555)
Y1  - 2022
U6  - https://doi.org/10.1029/2021SW002774
SN  - 1542-7390
VL  - 20
IS  - 5
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kühn, Daniela
A1  - Hainzl, Sebastian
A1  - Dahm, Torsten
A1  - Richter, Gudrun
A1  - Vera Rodriguez, Ismael
T1  - A review of source models to further the understanding of the seismicity of the Groningen field
JF  - Netherlands journal of geosciences : NJG
N2  - The occurrence of felt earthquakes due to gas production in Groningen has initiated numerous studies and model attempts to understand and quantify induced seismicity in this region. The whole bandwidth of available models spans the range from fully deterministic models to purely empirical and stochastic models. In this article, we summarise the most important model approaches, describing their main achievements and limitations. In addition, we discuss remaining open questions and potential future directions of development.
KW  - deterministic
KW  - empirical
KW  - hybrid
KW  - machine learning
KW  - seismicity model
Y1  - 2022
U6  - https://doi.org/10.1017/njg.2022.7
SN  - 0016-7746
SN  - 1573-9708
VL  - 101
PB  - Cambridge Univ. Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Kumar, Satish
A1  - Guntu, Ravi Kumar
A1  - Agarwal, Ankit
A1  - Villuri, Vasant Govind Kumar
A1  - Pasupuleti, Srinivas
A1  - Kaushal, Deo Raj
A1  - Gosian, Ashwin Kumar
A1  - Bronstert, Axel
T1  - Multi-objective optimization for stormwater management by green-roofs and infiltration trenches to reduce urban flooding in central Delhi
JF  - Journal of hydrology
N2  - Urban surface runoff management via best management practices (BMP) and low impact development (LID) has earned significant recognition owing to positive environmental and ecological impacts. However, due to the complexity of the parameters involved, the estimation of LID efficiency in attenuating the urban surface runoff at the watershed scale is challenging. A planning analysis of employing Green Roofs and Infiltration Trenches as BMPs/LIDs practices for urban surface runoff control is presented in this study. A multi-objective optimization decision-making framework is established by coupling SWMM (Storm Water Management Model) with NSGA-II models to check the performance of BMPs/LIDs concerning the cost-benefit analysis of LID at the watershed scale. Two urbanized areas belonging to Central Delhi in India were used as case studies. The results showed that the SWMM model is useful in simulating optimization problems for managing urban surface runoff. The optimum scenarios efficiently minimized the urban runoff volume while maintaining the BMPs/LIDs implementation costs and size. With BMPs/LIDs implementation, the reduction in runoff volume increases as expenses increase initially; however, there is no noticeable reduction in flood volume after a certain threshold. Contrasted with the haphazard arrangement of BMPs/LIDs, the proposed approach demonstrates 22%-24% runoff reductions for the same expenditures in watershed 1 and 23%-26% in watershed 2. The result of the study provides insights into planning and management of the urban surface runoff control with LID practices. The proposed framework assists the hydrologists in optimum selection and placements of BMPs/LIDs practices to acquire the most extreme ecological advantages with the least expenses.
KW  - Storm water management model
KW  - Genetic algorithm
KW  - NSGA-II
KW  - Best management practice
KW  - Low impact development
KW  - Cost-benefit
Y1  - 2022
U6  - https://doi.org/10.1016/j.jhydrol.2022.127455
SN  - 0022-1694
SN  - 1879-2707
VL  - 606
PB  - Elsevier
CY  - Amsterdam
ER  -