TY  - JOUR
A1  - Ezpeleta, Miguel
A1  - Parra, Mauricio
A1  - Collo, Gilda
A1  - Wunderlin, Cecilia
A1  - Borrego, Angeles G.
A1  - Sobel, Edward
A1  - Glodny, Johannes
T1  - Thermochronometry unveils ancient thermal regimes in the NW Pampean Ranges, Argentina
BT  - from Mesozoic rifting to Miocene flat-slab subduction
JF  - Basin research
N2  - Reconstructing thermal histories in thrust belts is commonly used to infer the age and rates of thrusting and hence the driving mechanisms of orogenesis. 
In areas where ancient basins have been incorporated into the orogenic wedge, a quantitative reconstruction of the thermal history helps distinguish among potential mechanisms responsible for heating events. 

We present such a reconstruction for the Ischigualasto-Villa Union basin in the western Pampean Ranges of Argentina, where Triassic rifting and late Cretaceous-Cenozoic retroarc foreland basin development has been widely documented, including Miocene flat-slab subduction. 
We report results of organic and inorganic thermal indicators acquired along three stratigraphic sections, including vitrinite reflectance and X-ray diffractometry in claystones and new thermochronological [(apatite fission-track and apatite and zircon [U-Th]/He)] analyses. 
Despite up to 5 km-thick Cenozoic overburden and unlike previously thought, the thermal peak in the basin is not due to Cenozoic burial but occurred in the Triassic, associated with a high heat flow of up to 90 mWm(-2) and <2 km of burial, which heated the base of the Triassic strata to similar to 160 degrees C. Following exhumation, attested by the development of an unconformity between the Triassic and Late-Cretaceous-Cenozoic sequences, Cenozoic re-burial increased the temperature to similar to 110 degrees C at the base of the Triassic section and only similar to 50 degrees C 7 km upsection, suggesting a dramatic decrease in the thermal gradient. 

The onset of Cenozoic cooling occurred at similar to 10(-8) Ma, concomitant with sediment accumulation and thus preceding the latest Miocene onset of thrusting that has been independently documented by stratigraphic-cross-cutting relationships. 
We argue that the onset of cooling is associated with lithospheric refrigeration following establishment of flat-slab subduction, leading to the eastward displacement of the asthenospheric wedge beneath the South American plate. 

Our study places time and temperature constraints on flat-slab cooling that calls for a careful interpretation of exhumation signals in thrustbelts inferred from thermochronology only.
KW  - %Ro
KW  - Cenozoic flat-slab
KW  - Ischigualasto-Villa Union Basin
KW  - thermochronological modelling (AFT, AHe and ZHe)
KW  - Triassic rifting
KW  - XRD in the clay fraction
KW  - heat flow
KW  - burial
Y1  - 2022
U6  - https://doi.org/10.1111/bre.12693
SN  - 0950-091X
SN  - 1365-2117
VL  - 34
IS  - 6
SP  - 1983
EP  - 2012
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - van Geffen, Femke
A1  - Heim, Birgit
A1  - Brieger, Frederic
A1  - Geng, Rongwei
A1  - Shevtsova, Iuliia
A1  - Schulte, Luise
A1  - Stuenzi, Simone M.
A1  - Bernhardt, Nadine
A1  - Troeva, Elena I.
A1  - Pestryakova, Luidmila Agafyevna
A1  - Zakharov, Evgenii S.
A1  - Pflug, Bringfried
A1  - Herzschuh, Ulrike
A1  - Kruse, Stefan
T1  - SiDroForest: a comprehensive forest inventory of Siberian boreal forest investigations including drone-based point clouds, individually labeled trees, synthetically generated tree crowns, and Sentinel-2 labeled image patches
JF  - Earth system science data
N2  - The SiDroForest (Siberian drone-mapped forest inventory) data collection is an attempt to remedy the scarcity of forest structure data in the circumboreal region by providing adjusted and labeled tree-level and vegetation plot-level data for machine learning and upscaling purposes. We present datasets of vegetation composition and tree and plot level forest structure for two important vegetation transition zones in Siberia, Russia; the summergreen-evergreen transition zone in Central Yakutia and the tundra-taiga transition zone in Chukotka (NE Siberia). The SiDroForest data collection consists of four datasets that contain different complementary data types that together support in-depth analyses from different perspectives of Siberian Forest plot data for multi-purpose applications. i. Dataset 1 provides unmanned aerial vehicle (UAV)-borne data products covering the vegetation plots surveyed during fieldwork (Kruse et al., 2021, ). The dataset includes structure-from-motion (SfM) point clouds and red-green-blue (RGB) and red-green-near-infrared (RGN) orthomosaics. From the orthomosaics, point-cloud products were created such as the digital elevation model (DEM), canopy height model (CHM), digital surface model (DSM) and the digital terrain model (DTM). The point-cloud products provide information on the three-dimensional (3D) structure of the forest at each plot. Dataset 2 contains spatial data in the form of point and polygon shapefiles of 872 individually labeled trees and shrubs that were recorded during fieldwork at the same vegetation plots (van Geffen et al., 2021c, ). The dataset contains information on tree height, crown diameter, and species type. These tree and shrub individually labeled point and polygon shapefiles were generated on top of the RGB UVA orthoimages. The individual tree information collected during the expedition such as tree height, crown diameter, and vitality are provided in table format. This dataset can be used to link individual information on trees to the location of the specific tree in the SfM point clouds, providing for example, opportunity to validate the extracted tree height from the first dataset. The dataset provides unique insights into the current state of individual trees and shrubs and allows for monitoring the effects of climate change on these individuals in the future. Dataset 3 contains a synthesis of 10 000 generated images and masks that have the tree crowns of two species of larch ( and ) automatically extracted from the RGB UAV images in the common objects in context (COCO) format (van Geffen et al., 2021a, ). As machine-learning algorithms need a large dataset to train on, the synthetic dataset was specifically created to be used for machine-learning algorithms to detect Siberian larch species. Larix gmeliniiLarix cajanderiDataset 4 contains Sentinel-2 (S-2) Level-2 bottom-of-atmosphere processed labeled image patches with seasonal information and annotated vegetation categories covering the vegetation plots (van Geffen et al., 2021b, ). The dataset is created with the aim of providing a small ready-to-use validation and training dataset to be used in various vegetation-related machine-learning tasks. It enhances the data collection as it allows classification of a larger area with the provided vegetation classes. The SiDroForest data collection serves a variety of user communities. <br /> The detailed vegetation cover and structure information in the first two datasets are of use for ecological applications, on one hand for summergreen and evergreen needle-leaf forests and also for tundra-taiga ecotones. Datasets 1 and 2 further support the generation and validation of land cover remote-sensing products in radar and optical remote sensing. In addition to providing information on forest structure and vegetation composition of the vegetation plots, the third and fourth datasets are prepared as training and validation data for machine-learning purposes. For example, the synthetic tree-crown dataset is generated from the raw UAV images and optimized to be used in neural networks. Furthermore, the fourth SiDroForest dataset contains S-2 labeled image patches processed to a high standard that provide training data on vegetation class categories for machine-learning classification with JavaScript Object Notation (JSON) labels provided. The SiDroForest data collection adds unique insights into remote hard-to-reach circumboreal forest regions.
Y1  - 2022
U6  - https://doi.org/10.5194/essd-14-4967-2022
SN  - 1866-3508
SN  - 1866-3516
VL  - 14
IS  - 11
SP  - 4967
EP  - 4994
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - 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  - Stuenzi, Simone Maria
A1  - Kruse, Stefan
A1  - Boike, Julia
A1  - Herzschuh, Ulrike
A1  - Oehme, Alexander
A1  - Pestryakova, Luidmila A.
A1  - Westermann, Sebastian
A1  - Langer, Moritz
T1  - Thermohydrological impact of forest disturbances on ecosystem-protected permafrost
JF  - Journal of geophysical research : Biogeosciences
N2  - Boreal forests cover over half of the global permafrost area and protect underlying permafrost. Boreal forest development, therefore, has an impact on permafrost evolution, especially under a warming climate. 

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

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

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

Only after surface fires, the most common disturbances, inducing low mortality rates, forests can recover and overpass pre-disturbance leaf area index values. We find that the trajectory of larch forests after surface fires is dependent on the precipitation conditions in the years after the disturbance. Dryer years can drastically change the direction of the larch forest development within the studied period.
KW  - permafrost
KW  - boreal forest
KW  - periglacial process
KW  - Siberia
KW  - larch forest
KW  - disturbance
Y1  - 2022
U6  - https://doi.org/10.1029/2021JG006630
SN  - 2169-8953
SN  - 2169-8961
VL  - 127
IS  - 5
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Herzschuh, Ulrike
A1  - Li, Chenzhi
A1  - Boehmer, Thomas
A1  - Postl, Alexander K.
A1  - Heim, Birgit
A1  - Andreev, Andrei A.
A1  - Cao, Xianyong
A1  - Wieczorek, Mareike
A1  - Ni, Jian
T1  - LegacyPollen 1.0
BT  - a taxonomically harmonized global late Quaternary pollen dataset of 2831 records with standardized chronologies
JF  - Earth system science data : ESSD
N2  - Here we describe the LegacyPollen 1.0, a dataset of 2831 fossil pollen records with metadata, a harmonized taxonomy, and standardized chronologies. 
A total of 1032 records originate from North America, 1075 from Europe, 488 from Asia, 150 from Latin America, 54 from Africa, and 32 from the Indo-Pacific. 

The pollen data cover the late Quaternary (mostly the Holocene). The original 10 110 pollen taxa names (including variations in the notations) were harmonized to 1002 terrestrial taxa (including Cyperaceae), with woody taxa and major herbaceous taxa harmonized to genus level and other herbaceous taxa to family level. 

The dataset is valuable for synthesis studies of, for example, taxa areal changes, vegetation dynamics, human impacts (e.g., deforestation), and climate change at global or continental scales. 

The harmonized pollen and metadata as well as the harmonization table are available from PANGAEA (https://doi.org/10.1594/PANGAEA.929773; Herzschuh et al., 2021). R code for the harmonization is provided at Zenodo (https://doi.org/10.5281/zenodo.5910972; Herzschuh et al., 2022) so that datasets at a customized harmonization level can be easily established.
Y1  - 2022
U6  - https://doi.org/10.5194/essd-14-3213-2022
SN  - 1866-3508
SN  - 1866-3516
VL  - 14
IS  - 7
SP  - 3213
EP  - 3227
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Glückler, Ramesh
A1  - Geng, Rongwei
A1  - Grimm, Lennart
A1  - Baisheva, Izabella
A1  - Herzschuh, Ulrike
A1  - Stoof-Leichsenring, Kathleen R.
A1  - Kruse, Stefan
A1  - Andreev, Andrej Aleksandrovic
A1  - Pestryakova, Luidmila
A1  - Dietze, Elisabeth
T1  - Holocene wildfire and vegetation dynamics in Central Yakutia, Siberia, reconstructed from lake-sediment proxies
JF  - Frontiers in Ecology and Evolution
N2  - Wildfires play an essential role in the ecology of boreal forests. 
In eastern Siberia, fire activity has been increasing in recent years, challenging the livelihoods of local communities. Intensifying fire regimes also increase disturbance pressure on the boreal forests, which currently protect the permafrost beneath from accelerated degradation. 

However, long-term relationships between changes in fire regime and forest structure remain largely unknown. 
We assess past fire-vegetation feedbacks using sedimentary proxy records from Lake Satagay, Central Yakutia, Siberia, covering the past c. 10,800 years. 

Results from macroscopic and microscopic charcoal analyses indicate high amounts of burnt biomass during the Early Holocene, and that the present-day, low-severity surface fire regime has been in place since c. 4,500 years before present. 
A pollen-based quantitative reconstruction of vegetation cover and a terrestrial plant record based on sedimentary ancient DNA metabarcoding suggest a pronounced shift in forest structure toward the Late Holocene. 

Whereas the Early Holocene was characterized by postglacial open larch-birch woodlands, forest structure changed toward the modern, mixed larch-dominated closed-canopy forest during the Mid-Holocene. 

We propose a potential relationship between open woodlands and high amounts of burnt biomass, as well as a mediating effect of dense larch forest on the climate-driven intensification of fire regimes. 
Considering the anticipated increase in forest disturbances (droughts, insect invasions, and wildfires), higher tree mortality may force the modern state of the forest to shift toward an open woodland state comparable to the Early Holocene. 
Such a shift in forest structure may result in a positive feedback on currently intensifying wildfires. 

These new long-term data improve our understanding of millennial-scale fire regime changes and their relationships to changes of vegetation in Central Yakutia, where the local population is already being confronted with intensifying wildfire seasons.
KW  - fire
KW  - larch
KW  - boreal
KW  - forest
KW  - Russia
KW  - charcoal
KW  - pollen
KW  - ancient DNA
Y1  - 2022
U6  - https://doi.org/10.3389/fevo.2022.962906
SN  - 2296-701X
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Song, Lina
A1  - Jie, Dongmei
A1  - Gao, Guizai
A1  - Liu, Lidan
A1  - Liu, Hongyan
A1  - Li, Dehui
A1  - Liu, Ying
T1  - Application of a topsoil phytolith dataset to quantitative paleoclimate reconstruction in Northeast China
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - Although phytoliths are recognized as an important proxy for paleoenvironmental reconstruction, the quantitative relationship between phytoliths and climate is still debated. In order to provide an improved basis for phytolith-based paleoclimate reconstructions, a representative modern phytolith dataset is essential. Here, we synthesize a modern topsoil phytolith dataset for Northeast China, analyze its climatic significance, and apply it to a fossil phytolith series from the Hani peat core in Northeast China. The dataset comprises 660 topsoil phytolith assemblages from 289 sample sites. We compiled modern meteorological data to assess the quantitative relationship between the phytolith assemblages and climatic variables. Detrended correspondence analysis (DCA) and Redundancy analysis (RDA) were used to determine the dominant climatic variable influencing the phytolith distributions. The results showed that mean annual temperature (MAT) is the dominant variable controlling the spatial distribution of phytoliths, accounting for 8.91% of the total variance. Transfer function based on inverse deshrinking locally-weighted weighted averaging (LWWA_Inv) was developed for MAT (R-_boot(2) = 0.86, RMSEP = 1.02 degrees C). Applying the LWWA_Inv transfer function to fossil phytolith records from the Hani peat core enables quantitative inferences to be made about Holocene climate changes in Northeast China. Overall, combined with the LWWA_Inv method, the topsoil phytolith dataset of Northeast China can be used for reliable quantitative MAT reconstruction.
KW  - Phytoliths
KW  - Northeast China
KW  - Transfer function
KW  - paleoclimate
KW  - reconstruction
Y1  - 2022
U6  - https://doi.org/10.1016/j.palaeo.2022.111108
SN  - 0031-0182
SN  - 1872-616X
VL  - 601
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Öztürk, Ugur
A1  - Bozzolan, Elisa
A1  - Holcombe, Elizabeth A.
A1  - Shukla, Roopam
A1  - Pianosi, Francesca
A1  - Wagener, Thorsten
T1  - How climate change and unplanned urban sprawl bring more landslides
JF  - Nature : the international weekly journal of science
N2  - More settlements will suffer as heavy rains and unregulated construction destabilize slopes in the tropics, models show.
KW  - Geophysics
KW  - Engineering
KW  - Climate change
KW  - Policy
Y1  - 2022
U6  - https://doi.org/10.1038/d41586-022-02141-9
SN  - 0028-0836
SN  - 1476-4687
VL  - 608
IS  - 7922
SP  - 262
EP  - 265
PB  - Nature portfolio
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Cruces-Zabala, José Alejandro
A1  - Ritter, Oliver
A1  - Weckmann, Ute
A1  - Tietze, Kristina
A1  - Meqbel, Naser M.
A1  - Audemard, Franck
A1  - Schmitz, Michael
T1  - Three-dimensional magnetotelluric imaging of the Merida Andes, Venezuela
JF  - Journal of South American earth sciences
N2  - The 100 km wide Merida Andes extend from the Colombian/Venezuelan border to the Coastal Cordillera. The mountain chain and its associated major strike-slip fault systems in western Venezuela formed due to oblique convergence of the Caribbean with the South American Plates and the north-eastwards expulsion of the North Andean Block. Due to the limited knowledge of lithospheric structures related to the formation of the Merida Andes research projects have been developed to illuminate this zone with deep geophysical data. In this study, we present three-dimensional inversion of broadband magnetotelluric data, collected along a 240 km long profile crossing the Merida Andes and the Maracaibo and Barinas-Apure foreland basins. The distribution of the stations limits resolution of the model to off-profile features. Combining 3D inversion of synthetic data sets derived from 3D modelling with 3D inversion of measured data, we could derive a 10 to 15 km wide corridor with good lateral resolution to develop hypotheses about the origin of deep-reaching anomalies of high electrical conductivity. The Merida Andes appear generally as electrically resistive structures, separated by anomalies associated with the most important fault systems of the region, the Bocono and Valera faults. Sensitivity tests suggest that the Valera Fault reaches to depths of up to 12 km and the Bocono Fault to more than 35 km depth. Both structures are connected to a sizeable conductor located east of the profile at 12-15 km depth. We propose that the high conductivity associated with this off-profile conductor may be related to the detachment of the Trujillo Block. We also identified a conductive zone that correlates spatially with the location of a gravity low, possibly representing a SE tilt of the Maracaibo Triangular Block under the mountain chain to great depths (>30 km). The relevance of these tectonic blocks in our models at crustal depths seems to be consistent with proposed theories that describe the geodynamics of western Venezuela as dominated by floating blocks or orogens. Our results stress the importance of the Trujillo Block for the current tectonic evolution of western Venezuela and confirm the relevance of the Bocono Fault carrying deformation to the lower crust and upper mantle. The Barinas-Apure and the Maracaibo sedimentary basins are imaged as electrically conductive with depths of 4 to 5 km and 5 to 10 km, respectively. The Barinas-Apure basin is imaged as a simple 1D structure, in contrast to the Maracaibo Basin, where a series of conductive and resistive bodies could be related to active deformation causing the juxtaposition of older geological formations and younger basin sediments.
KW  - Magnetotellurics
KW  - Merida Andes
KW  - Geodynamics
KW  - Trujillo Block
KW  - Chain structure
KW  - Strike-slip faults
KW  - Bocono
Y1  - 2022
U6  - https://doi.org/10.1016/j.jsames.2022.103711
SN  - 0895-9811
SN  - 1873-0647
VL  - 114
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Li, Wenjia
A1  - Tian, Fang
A1  - Rudaya, Natalya A.
A1  - Herzschuh, Ulrike
A1  - Cao, Xianyong
T1  - Pollen-based holocene thawing-history of permafrost in Northern Asia and its potential impacts on climate change
JF  - Frontiers in Ecology and Evolution
N2  - As the recent permafrost thawing of northern Asia proceeds due to anthropogenic climate change, precise and detailed palaeoecological records from past warm periods are essential to anticipate the extent of future permafrost variations. Here, based on the modern relationship between permafrost and vegetation (represented by pollen assemblages), we trained a Random Forest model using pollen and permafrost data and verified its reliability to reconstruct the history of permafrost in northern Asia during the Holocene. An early Holocene (12-8 cal ka BP) strong thawing trend, a middle-to-late Holocene (8-2 cal ka BP) relatively slow thawing trend, and a late Holocene freezing trend of permafrost in northern Asia are consistent with climatic proxies such as summer solar radiation and Northern Hemisphere temperature. The extensive distribution of permafrost in northern Asia inhibited the spread of evergreen coniferous trees during the early Holocene warming and might have decelerated the enhancement of the East Asian summer monsoon (EASM) by altering hydrological processes and albedo. Based on these findings, we suggest that studies of the EASM should consider more the state of permafrost and vegetation in northern Asia, which are often overlooked and may have a profound impact on climate change in this region.
KW  - pollen
KW  - Random Forest
KW  - Siberia
KW  - East Asian summer monsoon
KW  - permafrost
Y1  - 2022
U6  - https://doi.org/10.3389/fevo.2022.894471
SN  - 2296-701X
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Zhang, Di
A1  - Cao, Kai
A1  - Yuan, Xiaoping
A1  - Wang, Guocan
A1  - van der Beek, Pieter A.
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  - Ariagno, Coline
A1  - Le Bouteiller, Caroline
A1  - van der Beek, Pieter A.
A1  - Klotz, Sébastien
T1  - Sediment export in marly badland catchments modulated by frost-cracking intensity, Draix–Bléone Critical Zone Observatory, SE France
JF  - Earth surface dynamics : ESURF ; an interactive open access journal of the European Geosciences Union
N2  - At the interface between the lithosphere and the atmosphere, the critical zone records the complex interactions between erosion, climate, geologic substrate, and life and can be directly monitored. Long data records (30 consecutive years for sediment yields) collected in the sparsely vegetated, steep, and small marly badland catchments of the Draix-Bleone Critical Zone Observatory (CZO), SE France, allow analyzing potential climatic controls on regolith dynamics and sediment export. Although widely accepted as a first-order control, rainfall variability does not fully explain the observed interannual variability in sediment export. Previous studies in this area have suggested that frost-weathering processes could drive regolith production and potentially modulate the observed pattern of sediment export. Here, we define sediment export anomalies as the residuals from a predictive model with annual rainfall intensity above a threshold as the control. We then use continuous soil temperature data recorded at different locations over multiple years to highlight the role of different frost-weathering processes (i.e., ice segregation versus volumetric expansion) in regolith production. Several proxies for different frost-weathering processes have been calculated from these data and compared to the sediment export anomalies, with careful consideration of field data quality. Our results suggest that frost-cracking intensity (linked to ice segregation) can explain about half (47 %-64 %) of the sediment export anomalies. In contrast, the number of freeze-thaw cycles (linked to volumetric expansion) has only a minor impact on catchment sediment response. The time spent below 0 degrees C also correlates well with the sediment export anomalies and requires fewer field data to be calculated than the frost-cracking intensity. Thus, frost-weathering processes modulate sediment export by controlling regolith production in these catchments and should be taken into account when building predictive models of sediment export from these badlands under a changing climate.
Y1  - 2022
U6  - https://doi.org/10.5194/esurf-10-81-2022
SN  - 2196-6311
SN  - 2196-632X
VL  - 10
IS  - 1
SP  - 81
EP  - 96
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Jones, Benjamin M.
A1  - Grosse, Guido
A1  - Farquharson, Louise M.
A1  - Roy-Léveillée, Pascale
A1  - Veremeeva, Alexandra
A1  - Kanevskiy, Mikhail Z.
A1  - Gaglioti, Benjamin
A1  - Breen, Amy L.
A1  - Parsekian, Andrew D.
A1  - Ulrich, Mathias
A1  - Hinkel, Kenneth M.
T1  - Lake and drained lake basin systems in lowland permafrost regions
JF  - Nature reviews earth and environment
N2  - The formation, growth and drainage of lakes in Arctic and boreal lowland permafrost regions influence landscape and ecosystem processes. These lake and drained lake basin (L-DLB) systems occupy >20% of the circumpolar Northern Hemisphere permafrost region and similar to 50% of the area below 300 m above sea level. Climate change is causing drastic impacts to L-DLB systems, with implications for permafrost dynamics, ecosystem functioning, biogeochemical processes and human livelihoods in lowland permafrost regions. In this Review, we discuss how an increase in the number of lakes as a result of permafrost thaw and an intensifying hydrologic regime are not currently offsetting the land area gained through lake drainage, enhancing the dominance of drained lake basins (DLBs).The contemporary transition from lakes to DLBs decreases hydrologic storage, leads to permafrost aggradation, increases carbon sequestration and diversifies the shifting habitat mosaic in Arctic and boreal regions. However, further warming could inhibit permafrost aggradation in DLBs, disrupting the trajectory of important microtopographic controls on carbon fluxes and ecosystem processes in permafrost-region L-DLB systems. Further research is needed to understand the future dynamics of L-DLB systems to improve Earth system models, permafrost carbon feedback assessments, permafrost hydrology linkages, infrastructure development in permafrost regions and the well-being of northern socio-ecological systems.
Y1  - 2022
U6  - https://doi.org/10.1038/s43017-021-00238-9
SN  - 2662-138X
VL  - 3
IS  - 1
SP  - 85
EP  - 98
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Fuchs, Matthias
A1  - Palmtag, Juri
A1  - Juhls, Bennet
A1  - Overduin, Pier Paul
A1  - Grosse, Guido
A1  - Abdelwahab, Ahmed
A1  - Bedington, Michael
A1  - Sanders, Tina
A1  - Ogneva, Olga
A1  - Fedorova, Irina
A1  - Zimov, Nikita S.
A1  - Mann, Paul J.
A1  - Strauss, Jens
T1  - High-resolution bathymetry models for the Lena Delta and Kolyma Gulf coastal zones
JF  - Earth system science data
N2  - Arctic river deltas and deltaic near-shore zones represent important land-ocean transition zones influencing sediment dynamics and nutrient fluxes from permafrost-affected terrestrial ecosystems into the coastal Arctic Ocean. To accurately model fluvial carbon and freshwater export from rapidly changing river catchments as well as assess impacts of future change on the Arctic shelf and coastal ecosystems, we need to understand the sea floor characteristics and topographic variety of the coastal zones. To date, digital bathymetrical data from the poorly accessible, shallow, and large areas of the eastern Siberian Arctic shelves are sparse. We have digitized bathymetrical information for nearly 75 000 locations from large-scale (1 V 25000-1 V 500000) current and historical nautical maps of the Lena Delta and the Kolyma Gulf region in northeastern Siberia. We present the first detailed and seamless digital models of coastal zone bathymetry for both delta and gulf regions in 50 and 200m spatial resolution. We validated the resulting bathymetry layers using a combination of our own water depth measurements and a collection of available depth measurements, which showed a strong correlation (r>0.9). Our bathymetrical models will serve as an input for a high-resolution coupled hydrodynamic-ecosystem model to better quantify fluvial and coastal carbon fluxes to the Arctic Ocean, but they may be useful for a range of other studies related to Arctic delta and near-shore dynamics such as modeling of submarine permafrost, near-shore sea ice, or shelf sediment transport. The new digital high-resolution bathymetry products are available on the PANGAEA data set repository for the Lena Delta (https://doi.org/10.1594/PANGAEA.934045; Fuchs et al., 2021a) and Kolyma Gulf region (https://doi.org/10.1594/PANGAEA.934049; Fuchs et al., 2021b), respectively. Likewise, the depth validation data are available on PANGAEA as well (https://doi.org/10.1594/PANGAEA.933187; Fuchs et al., 2021c).
Y1  - 2022
U6  - https://doi.org/10.5194/essd-14-2279-2022
SN  - 1866-3508
SN  - 1866-3516
VL  - 14
IS  - 5
SP  - 2279
EP  - 2301
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Repasch, Marisa
A1  - Scheingross, Joel S.
A1  - Hovius, Niels
A1  - Vieth-Hillebrand, Andrea
A1  - Mueller, Carsten W.
A1  - Höschen, Carmen
A1  - Szupiany, Ricardo N.
A1  - Sachse, Dirk
T1  - River organic carbon fluxes modulated by hydrodynamic sorting of particulate organic matter
JF  - Geophysical research letters
N2  - Rivers regulate the global carbon cycle by transferring particulate organic carbon (POC) from terrestrial landscapes to marine sedimentary basins, but the processes controlling the amount and composition of fluvially exported POC are poorly understood. We propose that hydrodynamic sorting processes modify POC fluxes during fluvial transit. We test this hypothesis by studying POC transported along a similar to 1,200 km reach of the Rio Bermejo, Argentina. Nanoscale secondary ion mass spectrometry revealed that POC was either fine, mineral-associated organic matter, or coarse discrete organic particles. Mineral-associated POC is more resistant to oxidation and has a lower particle settling velocity than discrete POC. Consequently, hydraulic sorting and downstream fining amplify the proportion of fine, mineral-associated POC from similar to 55% to similar to 78% over 1,220 km of downstream transit. This suggests that mineral-associated POC has a greater probability of export and preservation in marine basins than plant detritus, which may be oxidized to CO2 during transit.
KW  - compound-specific stable isotopes
KW  - carbon fluxes
KW  - rivers
KW  - NanoSIMS;
KW  - sediment transport
KW  - hydrodynamic sorting
Y1  - 2022
U6  - https://doi.org/10.1029/2021GL096343
SN  - 0094-8276
SN  - 1944-8007
VL  - 49
IS  - 3
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Jara Muñoz, Julius
A1  - Melnick, Daniel
A1  - Li, Shaoyang
A1  - Socquet, Anne
A1  - Cortés-Aranda, Joaquín
A1  - Brill, Dominik
A1  - Strecker, Manfred
T1  - The cryptic seismic potential of the Pichilemu blind fault in Chile revealed by off-fault geomorphology
JF  - Nature Communications
N2  - The first step towards assessing hazards in seismically active regions involves mapping capable faults and estimating their recurrence times. While the mapping of active faults is commonly based on distinct geologic and geomorphic features evident at the surface, mapping blind seismogenic faults is complicated by the absence of on-fault diagnostic features. Here we investigated the Pichilemu Fault in coastal Chile, unknown until it generated a Mw 7.0 earthquake in 2010. The lack of evident surface faulting suggests activity along a partly-hidden blind fault. We used off-fault deformed marine terraces to estimate a fault-slip rate of 0.52 ± 0.04 m/ka, which, when integrated with satellite geodesy suggests a 2.12 ± 0.2 ka recurrence time for Mw~7.0 normal-faulting earthquakes. We propose that extension in the Pichilemu region is associated with stress changes during megathrust earthquakes and accommodated by sporadic slip during upper-plate earthquakes, which has implications for assessing the seismic potential of cryptic faults along convergent margins and elsewhere.
Y1  - 2022
U6  - https://doi.org/10.1038/s41467-022-30754-1
SN  - 2041-1723
VL  - 13
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Flóvenz, Ólafur G.
A1  - Wang, Rongjiang
A1  - Hersir, Gylfi Páll
A1  - Dahm, Torsten
A1  - Hainzl, Sebastian
A1  - Vassileva, Magdalena
A1  - Drouin, Vincent
A1  - Heimann, Sebastian
A1  - Isken, Marius Paul
A1  - Gudnason, Egill Á.
A1  - Ágústsson, Kristján
A1  - Ágústsdóttir, Thorbjörg
A1  - Horálek, Josef
A1  - Motagh, Mahdi
A1  - Walter, Thomas R.
A1  - Rivalta, Eleonora
A1  - Jousset, Philippe
A1  - Krawczyk, Charlotte M.
A1  - Milkereit, Claus
T1  - Cyclical geothermal unrest as a precursor to Iceland's 2021 Fagradalsfjall eruption
JF  - Nature geoscience
N2  - Understanding and constraining the source of geodetic deformation in volcanic areas is an important component of hazard assessment. Here, we analyse deformation and seismicity for one year before the March 2021 Fagradalsfjall eruption in Iceland. We generate a high-resolution catalogue of 39,500 earthquakes using optical cable recordings and develop a poroelastic model to describe three pre-eruptional uplift and subsidence cycles at the Svartsengi geothermal field, 8 km west of the eruption site. We find the observed deformation is best explained by cyclic intrusions into a permeable aquifer by a fluid injected at 4 km depth below the geothermal field, with a total volume of 0.11 ± 0.05 km3 and a density of 850 ± 350 kg m–3. We therefore suggest that ingression of magmatic CO2 can explain the geodetic, gravity and seismic data, although some contribution of magma cannot be excluded.
Y1  - 2022
U6  - https://doi.org/10.1038/s41561-022-00930-5
SN  - 1752-0894
SN  - 1752-0908
VL  - 15
IS  - 5
SP  - 397
EP  - 404
PB  - Nature Research
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Veh, Georg
A1  - Lützow, Natalie
A1  - Kharlamova, Varvara
A1  - Petrakov, Dmitry
A1  - Hugonnet, Romain
A1  - Korup, Oliver
T1  - Trends, Breaks, and Biases in the Frequency of Reported Glacier Lake Outburst Floods
JF  - Earth's Future
N2  - Thousands of glacier lakes have been forming behind natural dams in high mountains following glacier retreat since the early 20th century. Some of these lakes abruptly released pulses of water and sediment with disastrous downstream consequences. Yet it remains unclear whether the reported rise of these glacier lake outburst floods (GLOFs) has been fueled by a warming atmosphere and enhanced meltwater production, or simply a growing research effort. Here we estimate trends and biases in GLOF reporting based on the largest global catalog of 1,997 dated glacier-related floods in six major mountain ranges from 1901 to 2017. We find that the positive trend in the number of reported GLOFs has decayed distinctly after a break in the 1970s, coinciding with independently detected trend changes in annual air temperatures and in the annual number of field-based glacier surveys (a proxy of scientific reporting). We observe that GLOF reports and glacier surveys decelerated, while temperature rise accelerated in the past five decades. Enhanced warming alone can thus hardly explain the annual number of reported GLOFs, suggesting that temperature-driven glacier lake formation, growth, and failure are weakly coupled, or that outbursts have been overlooked. Indeed, our analysis emphasizes a distinct geographic and temporal bias in GLOF reporting, and we project that between two to four out of five GLOFs on average might have gone unnoticed in the early to mid-20th century. We recommend that such biases should be considered, or better corrected for, when attributing the frequency of reported GLOFs to atmospheric warming.
Y1  - 2022
U6  - https://doi.org/10.1029/2021EF002426
SN  - 2328-4277
VL  - 10
SP  - 1
EP  - 14
PB  - Wiley-Blackwell
CY  - Hoboken, New Jersey
ET  - 3
ER  - 
TY  - JOUR
A1  - Najman, Yani
A1  - Sobel, Edward
A1  - Millar, Ian
A1  - Luan, Xiwu
A1  - Zapata, Sebastian
A1  - Garzanti, Eduardo
A1  - Parra, Mauricio
A1  - Vezzoli, Giovanni
A1  - Zhang, Peng
A1  - Wa Aung, Day
A1  - Paw, Saw Mu Tha Lay
A1  - Lwin, Thae Naung
T1  - The timing of collision between Asia and the West Burma Terrane, and the development of the Indo-Burman Ranges
JF  - Tectonics
N2  - The West Burma Terrane (WBT) is a small terrane bounded to the east by the Asian Sibumasu Block and to the west by the Indo-Burman Ranges (IBR), the latter being an exhumed accretionary prism that formed during subduction of Indian oceanic lithosphere beneath Asia. Understanding the geological history of the WBT is important for reconstruction of the closure history of the Tethys Ocean and India-Asia collision. Currently there are major discrepancies in the proposed timings of collision between the WBT with both India and Asia; whether the WBT collided with India or Asia first is debated, and proposed timings of collisions stretch from the Mesozoic to the Cenozoic. We undertook a multi-technique provenance study involving petrography, detrital zircon U-Pb and Hf analyses, rutile U-Pb analyses and Sr-Nd bulk rock analyses on sediments of the Central Myanmar Basins of the WBT. We determined that the first arrival of Asian material into the basin occurred after the earliest late Eocene and by the early Oligocene, thus placing a minimum constraint on the timing of WBT-Asia collision. Our low temperature thermochronological study of the IBR records two periods of exhumation, in the early-middle Eocene, and at the Oligo-Miocene boundary. The Eocene event may be associated with the collision of the WBT with India. The later event at the Oligo-Miocene boundary may be associated with changes in wedge dynamics resulting from increased sediment supply to the system; however a number of other possible causes provide equally plausible explanations for both events.
KW  - Central Myanmar Basin
KW  - Indo-Burman Ranges
KW  - low temperature thermochronology
KW  - detrital provenance
KW  - West Burma Terrane
Y1  - 2022
U6  - https://doi.org/10.1029/2021TC007057
SN  - 0278-7407
SN  - 1944-9194
VL  - 41
IS  - 7
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kothari, Kritika
A1  - Battisti, Rafael
A1  - Boote, Kenneth J.
A1  - Archontoulis, Sotirios
A1  - Confalone, Adriana
A1  - Constantin, Julie
A1  - Cuadra, Santiago
A1  - Debaeke, Philippe
A1  - Faye, Babacar
A1  - Grant, Brian
A1  - Hoogenboom, Gerrit
A1  - Jing, Qi
A1  - van der Laan, Michael
A1  - Macena da Silva, Fernando Antonio
A1  - Marin, Fabio R.
A1  - Nehbandani, Alireza
A1  - Nendel, Claas
A1  - Purcell, Larry C.
A1  - Qian, Budong
A1  - Ruane, Alex C.
A1  - Schoving, Celine
A1  - Silva, Evandro H. F. M.
A1  - Smith, Ward
A1  - Soltani, Afshin
A1  - Srivastava, Amit
A1  - Vieira, Nilson A.
A1  - Slone, Stacey
A1  - Salmeron, Montserrat
T1  - Are soybean models ready for climate change food impact assessments?
JF  - European journal of agronomy : the official journal of the European Society for Agronomy
N2  - An accurate estimation of crop yield under climate change scenarios is essential to quantify our ability to feed a growing population and develop agronomic adaptations to meet future food demand. A coordinated evaluation of yield simulations from process-based eco-physiological models for climate change impact assessment is still missing for soybean, the most widely grown grain legume and the main source of protein in our food chain. In this first soybean multi-model study, we used ten prominent models capable of simulating soybean yield under varying temperature and atmospheric CO2 concentration [CO2] to quantify the uncertainty in soybean yield simulations in response to these factors. Models were first parametrized with high quality measured data from five contrasting environments. We found considerable variability among models in simulated yield responses to increasing temperature and [CO2]. For example, under a + 3 degrees C temperature rise in our coolest location in Argentina, some models simulated that yield would reduce as much as 24%, while others simulated yield increases up to 29%. In our warmest location in Brazil, the models simulated a yield reduction ranging from a 38% decrease under + 3 degrees C temperature rise to no effect on yield. Similarly, when increasing [CO2] from 360 to 540 ppm, the models simulated a yield increase that ranged from 6% to 31%. Model calibration did not reduce variability across models but had an unexpected effect on modifying yield responses to temperature for some of the models. The high uncertainty in model responses indicates the limited applicability of individual models for climate change food projections. However, the ensemble mean of simulations across models was an effective tool to reduce the high uncertainty in soybean yield simulations associated with individual models and their parametrization. Ensemble mean yield responses to temperature and [CO2] were similar to those reported from the literature. Our study is the first demonstration of the benefits achieved from using an ensemble of grain legume models for climate change food projections, and highlights that further soybean model development with experiments under elevated [CO2] and temperature is needed to reduce the uncertainty from the individual models.
KW  - Agricultural Model Inter-comparison and Improvement Project (AgMIP);
KW  - Model ensemble
KW  - Model calibration
KW  - Temperature
KW  - Atmospheric CO2
KW  - concentration
KW  - Legume model
Y1  - 2022
U6  - https://doi.org/10.1016/j.eja.2022.126482
SN  - 1161-0301
SN  - 1873-7331
VL  - 135
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Allroggen, Niklas
A1  - Heincke, Bjorn H.
A1  - Koyan, Philipp
A1  - Wheeler, Walter
A1  - Ronning, Jan S.
T1  - 3D ground-penetrating radar attribute classification
BT  - a case study from a paleokarst breccia pipe in the Billefjorden area on Spitsbergen, Svalbard
JF  - Geophysics
N2  - Ground-penetrating radar (GPR) is a method that can provide detailed information about the near subsurface in sedimentary and carbonate environments. 
The classical interpretation of GPR data (e.g., based on manual feature selection) often is labor-intensive and limited by the experience of the intercally used for seismic interpretation, can provide faster, more repeatable, and less biased interpretations. We have recorded a 3D GPD data set collected across a paleokarst breccia pipe in the Billefjorden area on Spitsbergen, Svalbard. After performing advanced processing, we compare the results of a classical GPR interpretation to the results of an attribute-based classification. 

Our attribute classification incorporates a selection of dip and textural attributes as the input for a k-means clustering approach. Similar to the results of the classical interpretation, the resulting classes differentiate between undisturbed strata and breccias or fault zones. 
The classes also reveal details inside the breccia pipe that are not discerned in the classical fer that the intrapipe GPR facies result from subtle differences, such as breccia lithology, clast size, or pore-space filling.
Y1  - 2022
U6  - https://doi.org/10.1190/GEO2021-0651.1
SN  - 0016-8033
SN  - 1942-2156
VL  - 87
IS  - 4
SP  - WB19
EP  - WB30
PB  - Society of Exploration Geophysicists
CY  - Tulsa
ER  - 
TY  - JOUR
A1  - Licht, Alexis
A1  - Kelson, Julia
A1  - Bergel, Shelly J.
A1  - Schauer, Andrew J.
A1  - Petersen, Sierra Victoria
A1  - Capirala, Ashika
A1  - Huntington, Katharine W.
A1  - Dupont-Nivet, Guillaume
A1  - Win, Zaw
A1  - Aung, Day Wa
T1  - Dynamics of pedogenic carbonate growth in the tropical domain of Myanmar
JF  - Geochemistry, geophysics, geosystems
N2  - Pedogenic carbonate is widespread at mid latitudes where warm and dry conditions favor soil carbonate growth from spring to fall. The mechanisms and timing of pedogenic carbonate formation are more ambiguous in the tropical domain, where long periods of soil water saturation and high soil respiration enhance calcite dissolution. This paper provides stable carbon, oxygen and clumped isotope values from Quaternary and Miocene pedogenic carbonates in the tropical domain of Myanmar, in areas characterized by warm (>18°C) winters and annual rainfall up to 1,700 mm. We show that carbonate growth in Myanmar is delayed to the driest and coldest months of the year by sustained monsoonal rainfall from mid spring to late fall. The range of isotopic variability in Quaternary pedogenic carbonates can be solely explained by temporal changes of carbonate growth within the dry season, from winter to early spring. We propose that high soil moisture year-round in the tropical domain narrows carbonate growth to the driest months and makes it particularly sensitive to the seasonal distribution of rainfall. This sensitivity is also enabled by high winter temperatures, allowing carbonate growth to occur outside the warmest months of the year. This high sensitivity is expected to be more prominent in the geological record during times with higher temperatures and greater expansion of the tropical realm. Clumped isotope temperatures, δ13C and δ18O values of tropical pedogenic carbonates are impacted by changes of both rainfall seasonality and surface temperatures; this sensitivity can potentially be used to track past tropical rainfall distribution.
KW  - clumped isotopes
KW  - pedogenic carbonate
KW  - monsoon
Y1  - 2022
U6  - https://doi.org/10.1029/2021GC009929
SN  - 1525-2027
VL  - 23
IS  - 7
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Rosa, Angelika D.
A1  - Dewaele, Agnès
A1  - Garbarino, Gaston
A1  - Svitlyk, Volodymyr
A1  - Morard, Guillaume
A1  - De Angelis, Filippo
A1  - Krstulovic, Marija
A1  - Briggs, Richard
A1  - Irifune, Tetsuo
A1  - Mathon, Olivier
A1  - Bouhifd, Mohamed Ali
T1  - Martensitic fcc-hcp transformation pathway in solid krypton and xenon and its effect on their equations of state
JF  - Physical review / publ. by The American Institute of Physics. B
N2  - The martensitic transformation is a fundamental physical phenomenon at the origin of important industrial applications. However, the underlying microscopic mechanism, which is of critical importance to explain the outstanding mechanical properties of martensitic materials, is still not fully understood. This is because for most martensitic materials the transformation is a fast process that makes in situ studies extremely challenging. Noble solids krypton and xenon undergo a progressive pressure-induced face-centered cubic (fcc) to hexagonal close-packed (hcp) martensitic transition with a very wide coexistence domain. Here, we took advantage of this unique feature to study the detailed transformation progress at the atomic level by employing in situ x-ray diffraction and absorption spectroscopy. We evidenced a four-stage pathway and suggest that the lattice mismatch between the fcc and hcp forms plays a key role in the generation of strain. We also determined precisely the effect of the transformation on the compression behavior of these materials.
Y1  - 2022
U6  - https://doi.org/10.1103/PhysRevB.105.144103
SN  - 2469-9950
SN  - 2469-9969
VL  - 105
IS  - 14
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - DeFelipe, Irene
A1  - Alcalde, Juan
A1  - Baykiev, Eldar
A1  - Bernal, Isabel
A1  - Boonma, Kittiphon
A1  - Carbonell, Ramon
A1  - Flude, Stephanie
A1  - Folch, Arnau
A1  - Fullea, Javier
A1  - García-Castellanos, Daniel
A1  - Geyer, Adelina
A1  - Giralt, Santiago
A1  - Hernández, Armand
A1  - Jiménez-Munt, Ivone
A1  - Kumar, Ajay
A1  - Llorens, Maria-Gema
A1  - Martí, Joan
A1  - Molina, Cecilia
A1  - Olivar-Castaño, Andrés
A1  - Parnell, Andrew
A1  - Schimmel, Martin
A1  - Torné, Montserrat
A1  - Ventosa, Sergi
T1  - Towards a digital twin of the Earth system: Geo-Soft-CoRe, a geoscientific software & code repository
JF  - Frontiers in earth science
N2  - The immense advances in computer power achieved in the last decades have had a significant impact in Earth science, providing valuable research outputs that allow the simulation of complex natural processes and systems, and generating improved forecasts. The development and implementation of innovative geoscientific software is currently evolving towards a sustainable and efficient development by integrating models of different aspects of the Earth system. This will set the foundation for a future digital twin of the Earth. The codification and update of this software require great effort from research groups and therefore, it needs to be preserved for its reuse by future generations of geoscientists. Here, we report on Geo-Soft-CoRe, a Geoscientific Software & Code Repository, hosted at the archive DIGITAL.CSIC. This is an open source, multidisciplinary and multiscale collection of software and code developed to analyze different aspects of the Earth system, encompassing tools to: 1) analyze climate variability; 2) assess hazards, and 3) characterize the structure and dynamics of the solid Earth. Due to the broad range of applications of these software packages, this collection is useful not only for basic research in Earth science, but also for applied research and educational purposes, reducing the gap between the geosciences and the society. By providing each software and code with a permanent identifier (DOI), we ensure its self-sustainability and accomplish the FAIR (Findable, Accessible, Interoperable and Reusable) principles. Therefore, we aim for a more transparent science, transferring knowledge in an easier way to the geoscience community, and encouraging an integrated use of computational infrastructure.
KW  - digital twin
KW  - software
KW  - code
KW  - global change
KW  - hazards
KW  - solid earth
Y1  - 2022
U6  - https://doi.org/10.3389/feart.2022.828005
SN  - 2296-6463
VL  - 10
PB  - Frontiers Media
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Krstulović, Marija
A1  - Rosa, Angelika D.
A1  - Ferreira Sanchez, Dario
A1  - Libon, Lélia
A1  - Albers, Christian
A1  - Merkulova, Margarita
A1  - Grolimund, Daniel
A1  - Irifune, Tetsuo
A1  - Wilke, Max
T1  - Effect of temperature on the densification of silicate melts to lower earth's mantle conditions
JF  - Physics of the earth and planetary interiors
N2  - Physical properties of silicate melts play a key role for global planetary dynamics, controlling for example volcanic eruption styles, mantle convection and elemental cycling in the deep Earth. They are significantly modified by structural changes at the atomic scale due to external parameters such as pressure and temperature or due to chemistry. Structural rearrangements such as 4- to 6-fold coordination change of Si with increasing depth may profoundly influence melt properties, but have so far mostly been studied at ambient temperature due to experimental difficulties. In order to investigate the structural properties of silicate melts and their densification mechanisms at conditions relevant to the deep Earth's interior, we studied haplo basaltic glasses and melts (albite-diopside composition) at high pressure and temperature conditions in resistively and laser-heated diamond anvil cells using X-ray absorption near edge structure spectroscopy. Samples were doped with 10 wt% of Ge, which is accessible with this experimental technique and which commonly serves as a structural analogue for the network forming cation Si. We acquired spectra on the Ge K edge up to 48 GPa and 5000 K and derived the average Ge-O coordination number NGe-O, and bond distance RGe-O as functions of pressure. Our results demonstrate a continuous transformation from tetrahedral to octahedral coordination between ca. 5 and 30 GPa at ambient temperature. Above 1600 K the data reveal a reduction of the pressure needed to complete conversion to octahedral coordination by ca. 30 %. The results allow us to determine the influence of temperature on the Si coordination number changes in natural melts in the Earth's interior. We propose that the complete transition to octahedral coordination in basaltic melts is reached at about 40 GPa, corresponding to a depth of ca. 1200 km in the uppermost lower mantle. At the core-mantle boundary (2900 km, 130 GPa, 3000 K) the existence of non-buoyant melts has been proposed to explain observed low seismic wave velocity features. Our results highlight that the melt composition can affect the melt density at such extreme conditions and may strongly influence the structural response.
KW  - Silicate melts
KW  - Densification
KW  - High pressure and high temperature;
KW  - XANES
KW  - Coordination number
KW  - Ultra-low velocity zones
Y1  - 2022
U6  - https://doi.org/10.1016/j.pepi.2021.106823
SN  - 0031-9201
SN  - 1872-7395
VL  - 323
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Cabieces, Roberto
A1  - Olivar‐Castaño, Andrés
A1  - Junqueira, Thiago C.
A1  - Relinque, Jesús
A1  - Fernandez-Prieto, Luis M.
A1  - Vackár, Jiří
A1  - Rösler, Boris
A1  - Barco, Jaime
A1  - Pazos, Antonio
A1  - García‐Martínez, Luz
T1  - Integrated Seismic Program (ISP): A new Python GUI-based software for earthquake seismology and seismic signal processing
JF  - Seismological research letters
N2  - Integrated Seismic Program (ISP) is a graphical user interface designed to facilitate and provide a user-friendly framework for performing diverse common and advanced tasks in seismological research. ISP is composed of five main modules for earthquake location, time-frequency analysis and advanced signal processing, implementation of array techniques to estimate the slowness vector, seismic moment tensor inversion, and receiver function computation and analysis. In addition, several support tools are available, allowing the user to create an event database, download data from International Federation of Digital Seismograph Networks services, inspect the background noise, and compute synthetic seismograms. ISP is written in Python3, supported by several open-source and/or publicly available tools. Its modular design allows for new features to be added in a collaborative development environment.
Y1  - 2022
U6  - https://doi.org/10.1785/0220210205
SN  - 0895-0695
SN  - 1938-2057
VL  - 93
IS  - 3
SP  - 1895
EP  - 1908
PB  - Seismological Society of America
CY  - Albany
ER  - 
TY  - JOUR
A1  - Schildgen, Taylor F.
A1  - van der Beek, Pieter A.
A1  - D'Arcy, Mitch
A1  - Roda-Boluda, Duna N.
A1  - Orr, Elizabeth N.
A1  - Wittmann, Hella
T1  - Quantifying drainage-divide migration from orographic rainfall over geologic timescales
BT  - Sierra de Aconquija, southern Central Andes
JF  - Earth & planetary science letters
N2  - Drainage-divide migration, controlled by rock-uplift and rainfall patterns, may play a major role in the geomorphic evolution of mountain ranges. 

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

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

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

Our findings place new constraints on the magnitudes and rates of drainage-divide migration in real landscapes, quantify the effects of orographic rainfall and erosion on the topographic evolution of a mountain range, and highlight the importance of considering drainage-divide migration when interpreting thermochronometer age patterns.
KW  - drainage-divide migration
KW  - landscape evolution
KW  - orographic rainfall
KW  - thermochronology
KW  - cosmogenic nuclides
KW  - Central Andes
Y1  - 2022
U6  - https://doi.org/10.1016/j.epsl.2021.117345
SN  - 0012-821X
SN  - 1385-013X
VL  - 579
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Barbosa, Luis Romero A.
A1  - Coelho, Victor Hugo R.
A1  - Gusmao, Ana Claudia V. L. F.
A1  - Fernandes, Lucila A. E.
A1  - da Silva, Bernardo B.
A1  - Galvao, Carlos de O.
A1  - Caicedo, Nelson O. L.
A1  - da Paz, Adriano R.
A1  - Xuan, Yunqing
A1  - Bertrand, Guillaume F.
A1  - Melo, Davi de C. D.
A1  - Montenegro, Suzana M. G. L.
A1  - Oswald, Sascha
A1  - Almeida, Cristiano das N.
T1  - A satellite-based approach to estimating spatially distributed groundwater recharge rates in a tropical wet sedimentary region despite cloudy conditions
JF  - Journal of hydrology
N2  - Groundwater recharge (GWR) is one of the most challenging water fluxes to estimate, as it relies on observed data that are often limited in many developing countries. 
This study developed an innovative water budget method using satellite products for estimating the spatially distributed GWR at monthly and annual scales in tropical wet sedimentary regions despite cloudy conditions. 

The distinctive features proposed in this study include the capacity to address 1) evapotranspiration estimations in tropical wet regions frequently overlaid by substantial cloud cover; and 2) seasonal root-zone water storage estimations in sedimentary regions prone to monthly variations. 

The method also utilises satellite-based information of the precipitation and surface runoff. The GWR was estimated and validated for the hydrologically contrasting years 2016 and 2017 over a tropical wet sedimentary region located in North-eastern Brazil, which has substantial potential for groundwater abstraction. 

This study showed that applying a cloud-cleaning procedure based on monthly compositions of biophysical data enables the production of a reasonable proxy for evapotranspiration able to estimate groundwater by the water budget method. 
The resulting GWR rates were 219 (2016) and 302 (2017) mm yr(-1), showing good correlations (CC = 0.68 to 0.83) and slight underestimations (PBIAS =-13 to-9%) when compared with the referenced estimates obtained by the water table fluctuation method for 23 monitoring wells. Sensitivity analysis shows that water storage changes account for +19% to-22% of our monthly evaluation. 

The satellite-based approach consistently demonstrated that the consideration of cloud-cleaned evapotranspiration and root-zone soil water storage changes are essential for a proper estimation of spatially distributed GWR in tropical wet sedimentary regions because of their weather seasonality and cloudy conditions.
KW  - remote sensing
KW  - water balance
KW  - groundwater recharge
KW  - water table
KW  - fluctuation
KW  - tropical climate
KW  - sedimentary aquifer
Y1  - 2022
U6  - https://doi.org/10.1016/j.jhydrol.2022.127503
SN  - 0022-1694
SN  - 1879-2707
VL  - 607
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Irrgang, Anna M.
A1  - Bendixen, Mette
A1  - Farquharson, Louise M.
A1  - Baranskaya, Alisa
A1  - Erikson, Li H.
A1  - Gibbs, Ann E.
A1  - Ogorodov, Stanislav A.
A1  - Overduin, Pier Paul
A1  - Lantuit, Hugues
A1  - Grigoriev, Mikhail N.
A1  - Jones, Benjamin M.
T1  - Drivers, dynamics and impacts of changing Arctic coasts
JF  - Nature reviews earth and environment
N2  - Arctic coasts are vulnerable to the effects of climate change, including rising sea levels and the loss of permafrost, sea ice and glaciers. Assessing the influence of anthropogenic warming on Arctic coastal dynamics, however, is challenged by the limited availability of observational, oceanographic and environmental data. Yet, with the majority of permafrost coasts being erosive, coupled with projected intensification of erosion and flooding, understanding these changes is critical. In this Review, we describe the morphological diversity of Arctic coasts, discuss important drivers of coastal change, explain the specific sensitivity of Arctic coasts to climate change and provide an overview of pan-Arctic shoreline change and its multifaceted impacts. Arctic coastal changes impact the human environment by threatening coastal settlements, infrastructure, cultural sites and archaeological remains. Changing sediment fluxes also impact the natural environment through carbon, nutrient and pollutant release on a magnitude that remains difficult to predict. Increasing transdisciplinary and interdisciplinary collaboration efforts will build the foundation for identifying sustainable solutions and adaptation strategies to reduce future risks for those living on, working at and visiting the rapidly changing Arctic coast.
Y1  - 2022
U6  - https://doi.org/10.1038/s43017-021-00232-1
SN  - 2662-138X
VL  - 3
IS  - 1
SP  - 39
EP  - 54
PB  - Nature Research
CY  - London
ER  - 
TY  - JOUR
A1  - Arboleda-Zapata, Mauricio
A1  - Guillemoteau, Julien
A1  - Tronicke, Jens
T1  - A comprehensive workflow to analyze ensembles of globally inverted 2D electrical resistivity models
JF  - Journal of applied geophysics
N2  - Electrical resistivity tomography (ERT) aims at imaging the subsurface resistivity distribution and provides valuable information for different geological, engineering, and hydrological applications. To obtain a subsurface resistivity model from measured apparent resistivities, stochastic or deterministic inversion procedures may be employed. Typically, the inversion of ERT data results in non-unique solutions; i.e., an ensemble of different models explains the measured data equally well. In this study, we perform inference analysis of model ensembles generated using a well-established global inversion approach to assess uncertainties related to the nonuniqueness of the inverse problem. Our interpretation strategy starts by establishing model selection criteria based on different statistical descriptors calculated from the data residuals. Then, we perform cluster analysis considering the inverted resistivity models and the corresponding data residuals. Finally, we evaluate model uncertainties and residual distributions for each cluster. To illustrate the potential of our approach, we use a particle swarm optimization (PSO) algorithm to obtain an ensemble of 2D layer-based resistivity models from a synthetic data example and a field data set collected in Loon-Plage, France. Our strategy performs well for both synthetic and field data and allows us to extract different plausible model scenarios with their associated uncertainties and data residual distributions. Although we demonstrate our workflow using 2D ERT data and a PSObased inversion approach, the proposed strategy is general and can be adapted to analyze model ensembles generated from other kinds of geophysical data and using different global inversion approaches.
KW  - Near-surface geophysics
KW  - Electrical resistivity tomography
KW  - Non-uniqueness
KW  - Global inversion
KW  - Particle swarm optimization
KW  - Ensemble
KW  - analysis
Y1  - 2021
U6  - https://doi.org/10.1016/j.jappgeo.2021.104512
SN  - 0926-9851
SN  - 1879-1859
VL  - 196
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Arboleda-Zapata, Mauricio
A1  - Angelopoulos, Michael
A1  - Overduin, Pier Paul
A1  - Grosse, Guido
A1  - Jones, Benjamin M.
A1  - Tronicke, Jens
T1  - Exploring the capabilities of electrical resistivity tomography to study subsea permafrost
JF  - The Cryosphere
N2  - Sea level rise and coastal erosion have inundated large areas of Arctic permafrost. Submergence by warm and saline waters increases the rate of inundated permafrost thaw compared to sub-aerial thawing on land. Studying the contact between the unfrozen and frozen sediments below the seabed, also known as the ice-bearing permafrost table (IBPT), provides valuable information to understand the evolution of sub-aquatic permafrost, which is key to improving and understanding coastal erosion prediction models and potential greenhouse gas emissions. In this study, we use data from 2D electrical resistivity tomography (ERT) collected in the nearshore coastal zone of two Arctic regions that differ in their environmental conditions (e.g., seawater depth and resistivity) to image and study the subsea permafrost. The inversion of 2D ERT data sets is commonly performed using deterministic approaches that favor smoothed solutions, which are typically interpreted using a user-specified resistivity threshold to identify the IBPT position. In contrast, to target the IBPT position directly during inversion, we use a layer-based model parameterization and a global optimization approach to invert our ERT data. This approach results in ensembles of layered 2D model solutions, which we use to identify the IBPT and estimate the resistivity of the unfrozen and frozen sediments, including estimates of uncertainties. Additionally, we globally invert 1D synthetic resistivity data and perform sensitivity analyses to study, in a simpler way, the correlations and influences of our model parameters. The set of methods provided in this study may help to further exploit ERT data collected in such permafrost environments as well as for the design of future field experiments.
Y1  - 2022
U6  - https://doi.org/10.5194/tc-16-4423-2022
SN  - 1994-0424
VL  - 16
SP  - 4423
EP  - 4445
PB  - Copernicus
CY  - Katlenburg-Lindau
ER  - 
TY  - JOUR
A1  - Klose, Tim
A1  - Guillemoteau, Julien
A1  - Vignoli, Giulio
A1  - Tronicke, Jens
T1  - Laterally constrained inversion (LCI) of multi-configuration EMI data with tunable sharpness
JF  - Journal of applied geophysics
N2  - Frequency-domain electromagnetic (FDEM) data are commonly inverted to characterize subsurface geoelectrical properties using smoothness constraints in 1D inversion schemes assuming a layered medium. 
Smoothness constraints are suitable for imaging gradual transitions of subsurface geoelectrical properties caused, for example, by varying sand, clay, or fluid content. However, such inversion approaches are limited in characterizing sharp interfaces. Alternative regularizations based on the minimum gradient support (MGS) stabilizers can, instead, be used to promote results with different levels of smoothness/sharpness selected by simply acting on the so-called focusing parameter. 
The MGS regularization has been implemented for different kinds of geophysical data inversion strategies. However, concerning FDEM data, the MGS regularization has only been implemented for vertically constrained inversion (VCI) approaches but not for laterally constrained inversion (LCI) approaches. 
We present a novel LCI approach for FDEM data using the MGS regularization for the vertical and lateral direction. Using synthetic and field data examples, we demonstrate that our approach can efficiently and automatically provide a set of model solutions characterized by different levels of sharpness and variable lateral consistencies. 
In terms of data misfit, the obtained set of solutions contains equivalent models allowing us also to investigate the non-uniqueness of FDEM data inversion.
KW  - frequency-domain electromagnetics
KW  - laterally constrained inversion
KW  - minimum gradient support regularization
KW  - peat characterization
Y1  - 2022
U6  - https://doi.org/10.1016/j.jappgeo.2021.104519
SN  - 0926-9851
VL  - 196
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Guillemoteau, Julien
A1  - Vignoli, Giulio
A1  - Barreto, Jeniffer
A1  - Sauvin, Guillaume
T1  - Sparse laterally constrained inversion of surface-wave dispersion curves via minimum gradient support regularization
JF  - Geophysics
N2  - We have developed a 1D laterally constrained inversion of surface-wave dispersion curves based on the minimum gradient support regularization, which allows solutions with tunable sharpness in the vertical and horizontal directions. The forward modeling consists of a finite-elements approach incorporated in a flexible nonparametric gradient-based inversion scheme, which has already demonstrated good stability and convergence capabilities when tested on other kinds of data. Our deterministic inversion procedure is performed in the shear-wave velocity log space as we noticed that the associated Jacobian indicates a reduced model dependency, and this, in turn, decreases the risks of local nonconvexity. We show several synthetics and one field example to demonstrate the effectiveness and the applicability of the proposed approach.
KW  - surface wave, inversion, near surface
Y1  - 2022
U6  - https://doi.org/10.1190/GEO2021-0247.1
SN  - 0016-8033
SN  - 1942-2156
VL  - 87
IS  - 3
SP  - R281
EP  - R289
PB  - Society of Exploration Geophysicists
CY  - Tulsa, Okla.
ER  - 
TY  - JOUR
A1  - Cesca, Simone
A1  - Sugan, Monica
A1  - Rudzinski, Lukasz
A1  - Vajedian, Sanaz
A1  - Niemz, Peter
A1  - Plank, Simon
A1  - Petersen, Gesa
A1  - Deng, Zhiguo
A1  - Rivalta, Eleonora
A1  - Vuan, Alessandro
A1  - Linares, Milton Percy Plasencia
A1  - Heimann, Sebastian
A1  - Dahm, Torsten
T1  - Massive earthquake swarm driven by magmatic intrusion at the Bransfield Strait, Antarctica
JF  - Communications earth and environment
N2  - An earthquake swarm affected the Bransfield Strait, Antarctica, a unique rift basin in transition from intra-arc rifting to ocean spreading. The swarm, counting similar to 85,000 volcano-tectonic earthquakes since August 2020, is located close to the Orca submarine volcano, previously considered inactive. Simultaneously, geodetic data reported up to similar to 11 cm north-westward displacement over King George Island. We use a broad variety of geophysical data and methods to reveal the complex migration of seismicity, accompanying the intrusion of 0.26-0.56 km(3) of magma. Strike-slip earthquakes mark the intrusion at depth, while shallower normal faulting the similar to 20 km long lateral growth of a dike. Seismicity abruptly decreased after a Mw 6.0 earthquake, suggesting the magmatic dike lost pressure with the slipping of a large fault. A seafloor eruption is likely, but not confirmed by sea surface temperature anomalies. The unrest documents episodic magmatic intrusion in the Bransfield Strait, providing unique insights into active continental rifting.
Y1  - 2022
U6  - https://doi.org/10.1038/s43247-022-00418-5
SN  - 2662-4435
VL  - 3
IS  - 1
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Lupien, Rachel L.
A1  - Russell, James M.
A1  - Pearson, Emma J.
A1  - Castaneda, Isla S.
A1  - Asrat, Asfawossen
A1  - Förster, Verena
A1  - Lamb, Henry F.
A1  - Roberts, Helen M.
A1  - Schäbitz, Frank
A1  - Trauth, Martin H.
A1  - Beck, Catherine C.
A1  - Feibel, Craig S.
A1  - Cohen, Andrew S.
T1  - Orbital controls on eastern African hydroclimate in the Pleistocene
JF  - Scientific reports
N2  - Understanding eastern African paleoclimate is critical for contextualizing early human evolution, adaptation, and dispersal, yet Pleistocene climate of this region and its governing mechanisms remain poorly understood due to the lack of long, orbitally-resolved, terrestrial paleoclimate records. Here we present leaf wax hydrogen isotope records of rainfall from paleolake sediment cores from key time windows that resolve long-term trends, variations, and high-latitude effects on tropical African precipitation. Eastern African rainfall was dominantly controlled by variations in low-latitude summer insolation during most of the early and middle Pleistocene, with little evidence that glacial-interglacial cycles impacted rainfall until the late Pleistocene. We observe the influence of high-latitude-driven climate processes emerging from the last interglacial (Marine Isotope Stage 5) to the present, an interval when glacial-interglacial cycles were strong and insolation forcing was weak. Our results demonstrate a variable response of eastern African rainfall to low-latitude insolation forcing and high-latitude-driven climate change, likely related to the relative strengths of these forcings through time and a threshold in monsoon sensitivity. We observe little difference in mean rainfall between the early, middle, and late Pleistocene, which suggests that orbitally-driven climate variations likely played a more significant role than gradual change in the relationship between early humans and their environment.
Y1  - 2022
U6  - https://doi.org/10.1038/s41598-022-06826-z
SN  - 2045-2322
VL  - 12
IS  - 1
PB  - Macmillan Publishers Limited
CY  - London
ER  - 
TY  - JOUR
A1  - Płóciennik, Mateusz
A1  - Zawiska, Izabela
A1  - Rzodkiewicz, Monika
A1  - Noryśkiewicz, Agnieszka M.
A1  - Słowiński, Michał
A1  - Müller, Daniela
A1  - Brauer, Achim
A1  - Antczak-Orlewska, Olga
A1  - Kramkowski, Mateusz
A1  - Peyron, Odile
A1  - Nevalainen, Liisa
A1  - Luoto, Tomi P.
A1  - Kotrys, Bartosz
A1  - Seppä, Heikki
A1  - Bidaurreta, Jon Camuera
A1  - Rudna, Marta
A1  - Mielczarek, Małgorzata
A1  - Zawisza, Edyta
A1  - Janowska, Ewa
A1  - Błaszkiewicz, Mirosław
T1  - Climatic and hydrological variability as a driver of the Lake Gościąż biota during the Younger Dryas
JF  - Catena
N2  - The Younger Dryas (YD) is a roughly 1,100-year cold period marking the end of the last glaciation. Climate modelling for northern Europe indicates high summer temperatures and strong continentality. In eastern Europe, the scale of temperature variation and its influence on ecosystems is weakly recognised. Here, we present a multi-proxy reconstruction of YD conditions from Lake Gos ' ciaz (central Poland). The decadal-resolution analysis of its annually varved sediments indicates an initial decrease in Chironomidae-inferred mean July air temperature followed by steady warming. The pollen-inferred winter-to-summer temperature amplitude and annual precip-itation is highest at the Allerod/YD transition and the early YD (ca. 12.7-12.4 ky cal BP) and YD/Holocene (11.7-11.4 ka cal BP) transition. Temperature and precipitation were the main reasons for lake level fluctuations as reflected in the planktonic/littoral Cladocera ratio. The lake's diatom-inferred total phosphorus decreased with increasing summer temperature from about mid YD. Windy conditions in the early YD until ~12.3 ka cal BP caused water mixing and a short-lived/temporary increase in nutrient availability for phytoplankton. The Chironomidae-inferred summer temperature and pollen inferred summer temperature, winter temperature and annual precipitation herein are one of only a few in eastern Europe conducted with such high resolution.
KW  - Late Glacial
KW  - Varved sediments
KW  - Climate reconstructions
KW  - Chironomidae
KW  - Cladocera
KW  - Pollen
KW  - Diatoms
Y1  - 2022
U6  - https://doi.org/10.1016/j.catena.2022.106049
SN  - 0341-8162
SN  - 1872-6887
VL  - 212
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  - 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  - Sarr, Anta-Clarisse
A1  - Donnadieu, Yannick
A1  - Bolton, Clara T.
A1  - Ladant, Jean-Baptiste
A1  - Licht, Alexis
A1  - Fluteau, Frédéric
A1  - Laugié, Marie
A1  - Tardif-Becquet, Delphine
A1  - Dupont-Nivet, Guillaume
T1  - Neogene South Asian monsoon rainfall and wind histories diverged due to topographic effects
JF  - Nature geoscience
N2  - The drivers of the evolution of the South Asian Monsoon remain widely debated. An intensification of monsoonal rainfall recorded in terrestrial and marine sediment archives from the earliest Miocene (23-20 million years ago (Ma)) is generally attributed to Himalayan uplift. However, Indian Ocean palaeorecords place the onset of a strong monsoon around 13 Ma, linked to strengthening of the southwesterly winds of the Somali Jet that also force Arabian Sea upwelling. Here we reconcile these divergent records using Earth system model simulations to evaluate the interactions between palaeogeography and ocean-atmosphere dynamics. We show that factors forcing the South Asian Monsoon circulation versus rainfall are decoupled and diachronous. Himalayan and Tibetan Plateau topography predominantly controlled early Miocene rainfall patterns, with limited impact on ocean-atmosphere circulation. The uplift of the East African and Middle Eastern topography played a pivotal role in the establishment of the modern Somali Jet structure above the western Indian Ocean, while strong upwelling initiated as a direct consequence of the emergence of the Arabian Peninsula and the onset of modern-like atmospheric circulation. Our results emphasize that although elevated rainfall seasonality was probably a persistent feature since the India-Asia collision in the Paleogene, modern-like monsoonal atmospheric circulation only emerged in the late Neogene.
Y1  - 2022
U6  - https://doi.org/10.1038/s41561-022-00919-0
SN  - 1752-0894
SN  - 1752-0908
VL  - 15
IS  - 4
SP  - 314
EP  - 319
PB  - Nature Research
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Toumoulin, Agathe
A1  - Tardif-Becquet, Delphine
A1  - Donnadieu, Yannick
A1  - Licht, Alexis
A1  - Ladant, Jean-Baptiste
A1  - Kunzmann, Lutz
A1  - Dupont-Nivet, Guillaume
T1  - Evolution of continental temperature seasonality from the Eocene greenhouse to the Oligocene icehouse
BT  - a model-data comparison
JF  - Climate of the past : an interactive open access journal of the European Geosciences Union
N2  - At the junction of greenhouse and icehouse climate states, the Eocene-Oligocene Transition (EOT) is a key moment in Cenozoic climate history. While it is associated with severe extinctions and biodiversity turnovers on land, the role of terrestrial climate evolution remains poorly resolved, especially the associated changes in seasonality. Some paleobotanical and geochemical continental records in parts of the Northern Hemisphere suggest the EOT is associated with a marked cooling in winter, leading to the development of more pronounced seasons (i.e., an increase in the mean annual range of temperature, MATR). However, the MATR increase has been barely studied by climate models and large uncertainties remain on its origin, geographical extent and impact. In order to better understand and describe temperature seasonality changes between the middle Eocene and the early Oligocene, we use the Earth system model IPSL-CM5A2 and a set of simulations reconstructing the EOT through three major climate forcings: pCO(2) decrease (1120, 840 and 560 ppm), the Antarctic ice-sheet (AIS) formation and the associated sea-level decrease. Our simulations suggest that pCO(2) lowering alone is not sufficient to explain the seasonality evolution described by the data through the EOT but rather that the combined effects of pCO(2) , AIS formation and increased continentality provide the best data-model agreement.pCO(2) decrease induces a zonal pattern with alternating increasing and decreasing seasonality bands particularly strong in the northern high latitudes (up to 8 degrees C MATR increase) due to sea-ice and surface albedo feedback. Conversely, the onset of the AIS is responsible for a more constant surface albedo yearly, which leads to a strong decrease in seasonality in the southern midlatitudes to high latitudes (> 40 degrees S). Finally, continental areas that emerged due to the sea-level lowering cause the largest increase in seasonality and explain most of the global heterogeneity in MATR changes (1MATR) patterns. The Delta MATR patterns we reconstruct are generally consistent with the variability of the EOT biotic crisis intensity across the Northern Hemisphere and provide insights on their underlying mechanisms.
Y1  - 2022
U6  - https://doi.org/10.5194/cp-18-341-2022
SN  - 1814-9324
SN  - 1814-9332
VL  - 18
IS  - 2
SP  - 341
EP  - 362
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Haugk, Charlotte
A1  - Jongejans, Loeka L.
A1  - Mangelsdorf, Kai
A1  - Fuchs, Matthias
A1  - Ogneva, Olga
A1  - Palmtag, Juri
A1  - Mollenhauer, Gesine
A1  - Mann, Paul J.
A1  - Overduin, P. Paul
A1  - Grosse, Guido
A1  - Sanders, Tina
A1  - Tuerena, Robyn E.
A1  - Schirrmeister, Lutz
A1  - Wetterich, Sebastian
A1  - Kizyakov, Alexander
A1  - Karger, Cornelia
A1  - Strauss, Jens
T1  - Organic matter characteristics of a rapidly eroding permafrost cliff in NE Siberia (Lena Delta, Laptev Sea region)
JF  - Biogeosciences
N2  - Organic carbon (OC) stored in Arctic permafrost represents one of Earth's largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits is still poorly quantified. We define the OM quality as the intrinsic potential for further transformation, decomposition and mineralisation. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecu- lar geochemical and carbon isotopic analyses of Late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last similar to 52 kyr. We showed that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt %). The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal ka BP) and are overlaid by last glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7-0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of isoand anteiso-branched fatty acids (FAs) relative to mid- and long-chain (C >= 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C/N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease in HPFA values downwards along the profile probably indicates stronger OM decomposition in the oldest (MIS 3) deposits of the cliff. The characterisation of OM from eroding permafrost leads to a better assessment of the greenhouse gas potential of the OC released into river and nearshore waters in the future.
Y1  - 2022
U6  - https://doi.org/10.5194/bg-19-2079-2022
SN  - 1726-4170
SN  - 1726-4189
VL  - 19
IS  - 7
SP  - 2079
EP  - 2094
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Voglimacci-Stephanopoli, Joëlle
A1  - Wendleder, Anna
A1  - Lantuit, Hugues
A1  - Langlois, Alexandre
A1  - Stettner, Samuel
A1  - Schmitt, Andreas
A1  - Dedieu, Jean-Pierre
A1  - Roth, Achim
A1  - Royer, Alain
T1  - Potential of X-band polarimetric synthetic aperture radar co-polar phase difference for arctic snow depth estimation
JF  - Cryosphere
N2  - Changes in snowpack associated with climatic warming has drastic impacts on surface energy balance in the cryosphere. Yet, traditional monitoring techniques, such as punctual measurements in the field, do not cover the full snowpack spatial and temporal variability, which hampers efforts to upscale measurements to the global scale. This variability is one of the primary constraints in model development. In terms of spatial resolution, active microwaves (synthetic aperture radar - SAR) can address the issue and outperform methods based on passive microwaves. Thus, high-spatial-resolution monitoring of snow depth (SD) would allow for better parameterization of local processes that drive the spatial variability of snow. The overall objective of this study is to evaluate the potential of the TerraSAR-X (TSX) SAR sensor and the wave co-polar phase difference (CPD) method for characterizing snow cover at high spatial resolution. Consequently, we first (1) investigate SD and depth hoar fraction (DHF) variability between different vegetation classes in the Ice Creek catchment (Qikiqtaruk/Herschel Island, Yukon, Canada) using in situ measurements collected over the course of a field campaign in 2019; (2) evaluate linkages between snow characteristics and CPD distribution over the 2019 dataset; and (3) determine CPD seasonality considering meteorological data over the 2015-2019 period. SD could be extracted using the CPD when certain conditions are met. A high incidence angle (>30 circle) with a high topographic wetness index (TWI) (>7.0) showed correlation between SD and CPD (R2 up to 0.72). Further, future work should address a threshold of sensitivity to TWI and incidence angle to map snow depth in such environments and assess the potential of using interpolation tools to fill in gaps in SD information on drier vegetation types.
Y1  - 2022
U6  - https://doi.org/10.5194/tc-16-2163-2022
SN  - 1994-0416
SN  - 1994-0424
VL  - 16
IS  - 6
SP  - 2163
EP  - 2181
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Kaya, Mustafa Yücel
A1  - Dupont-Nivet, Guillaume
A1  - Frieling, Joost
A1  - Fioroni, Chiara
A1  - Rohrmann, Alexander
A1  - Altıner, Sevinç Özkan
A1  - Vardar, Ezgi
A1  - Tanyas, Hakan
A1  - Mamtimin, Mehmut
A1  - Zhaojie, Guo
T1  - The Eurasian epicontinental sea was an important carbon sink during the Palaeocene-Eocene thermal maximum
JF  - Communications earth and environment
N2  - The Palaeocene-Eocene Thermal Maximum (ca. 56 million years ago) offers a primary analogue for future global warming and carbon cycle recovery. Yet, where and how massive carbon emissions were mitigated during this climate warming event remains largely unknown. Here we show that organic carbon burial in the vast epicontinental seaways that extended over Eurasia provided a major carbon sink during the Palaeocene-Eocene Thermal Maximum. We coupled new and existing stratigraphic analyses to a detailed paleogeographic framework and using spatiotemporal interpolation calculated ca. 720–1300 Gt organic carbon excess burial, focused in the eastern parts of the Eurasian epicontinental seaways. A much larger amount (2160–3900 Gt C, and when accounting for the increase in inundated shelf area 7400–10300 Gt C) could have been sequestered in similar environments globally. With the disappearance of most epicontinental seas since the Oligocene-Miocene, an effective negative carbon cycle feedback also disappeared making the modern carbon cycle critically dependent on the slower silicate weathering feedback.
Y1  - 2022
U6  - https://doi.org/10.1038/s43247-022-00451-4
SN  - 2662-4435
VL  - 3
IS  - 1
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Yuan, Xiaoping P.
A1  - Jiao, Ruohong
A1  - Dupont-Nivet, Guillaume
A1  - Shen, Xiaoming
T1  - Southeastern Tibetan Plateau growth revealed by inverse analysis of landscape evolution model
JF  - Geophysical research letters
N2  - The Cenozoic history of the Tibetan Plateau topography is critical for understanding the evolution of the Indian-Eurasian collision, climate, and biodiversity. However, the long-term growth and landscape evolution of the Tibetan Plateau remain ambiguous, it remains unclear if plateau uplift occurred soon after the India-Asia collision in the Paleogene (similar to 50-25 Ma) or later in the Neogene (similar to 20-5 Ma). Here, we reproduce the uplift history of the southeastern Tibetan Plateau using a 2D landscape evolution model, which simultaneously solves fluvial erosion and sediment transport processes in the drainage basins of the Three Rivers region (Yangtze, Mekong, and Salween Rivers). Our model was optimized through a formal inverse analysis with 20,000 forward simulations, which aims to reconcile the transient states of the present-day river profiles. The results, compared to existing paleoelevation and thermochronologic data, suggest initially low elevations (similar to 300-500 m) during the Paleogene, followed by a gradual southeastward propagation of topographic uplift of the plateau margin.
KW  - Tibetan Plateau
KW  - landscape evolution
KW  - fluvial erosion
KW  - inverse analysis
KW  - mountain growth
KW  - propagating uplift
Y1  - 2022
U6  - https://doi.org/10.1029/2021GL097623
SN  - 0094-8276
SN  - 1944-8007
VL  - 49
IS  - 10
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Bannister, Stephen
A1  - Bertrand, Edward A.
A1  - Heimann, Sebastian
A1  - Bourguignon, Sandra
A1  - Asher, Cameron
A1  - Shanks, Jackson
A1  - Harvison, Adrian
T1  - Imaging sub-caldera structure with local seismicity, Okataina Volcanic Centre, Taupo Volcanic Zone, using double-difference seismic tomography
JF  - Journal of volcanology and geothermal research
N2  - We examine sub-caldera structure and seismicity in and around the Okataina Volcanic Centre (OVC), Taupo Volcanic Zone, New Zealand, using seismic data collected over 4+ years with a temporary array of broadband and short-period seismometers, supplementing data from the permanent New Zealand seismometer network. 

We derive a new 3-D image of P-wave seismic velocity for the upper crust in the region, using double-difference seismic tomography and utilising waveform cross-correlations. We subsequently relocate 6989 earthquakes which occurred in the region over the 2010-2021 time period, using the 3D velocity model. 
The seismicity distribution shows spatial clusters west of Lake Rotomahana, as well as beneath Haroharo and the Makatiti Dome, inside the Okataina caldera. Beneath Makatiti Dome 90% of the events are shallower than 7.7 +/- 0.5 km. 

Outside of the Okataina caldera event relocations highlight short (similar to 3-4 km long) streaks of activity in the Ngakuru graben, part of the active Taupo Rift southwest of Okataina caldera. Inside the OVC the relocated seismicity beneath Makatiti appears closely associated with low (similar to 10%) P-wave velocity anomalies, which we resolve in the similar to 5-to-8-km depth range beneath the Okataina caldera, and which are likely related to partial melt and/or fluid-volatile pathways. 
Moment tensor analyses for two larger-magnitude events (M(L)4.5 and M(L)4.9) near Haroharo indicate normal faulting, with NNE-SSW fault strike, but with positive CLVD and positive isotropic components when allowing for a full moment tensor, consistent with a magmatic environment with degassing and/or fluid migration.
KW  - Okataina Caldera
KW  - Taupo Rift
KW  - seismic tomography
KW  - sub-caldera structure
KW  - Volcanic system
Y1  - 2022
U6  - https://doi.org/10.1016/j.jvolgeores.2022.107653
SN  - 0377-0273
SN  - 1872-6097
VL  - 431
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Steirou, Eva
A1  - Gerlitz, Lars
A1  - Sun, Xun
A1  - Apel, Heiko
A1  - Agarwal, Ankit
A1  - Totz, Sonja Juliana
A1  - Merz, Bruno
T1  - Towards seasonal forecasting of flood probabilities in Europe using climate and catchment information
JF  - Scientific reports
N2  - We investigate whether the distribution of maximum seasonal streamflow is significantly affected by catchment or climate state of the season/month ahead. We fit the Generalized Extreme Value (GEV) distribution to extreme seasonal streamflow for around 600 stations across Europe by conditioning the GEV location and scale parameters on 14 indices, which represent the season-ahead climate or catchment state. The comparison of these climate-informed models with the classical GEV distribution, with time-constant parameters, suggests that there is a substantial potential for seasonal forecasting of flood probabilities. The potential varies between seasons and regions. Overall, the season-ahead catchment wetness shows the highest potential, although climate indices based on large-scale atmospheric circulation, sea surface temperature or sea ice concentration also show some skill for certain regions and seasons. Spatially coherent patterns and a substantial fraction of climate-informed models are promising signs towards early alerts to increase flood preparedness already a season ahead.
Y1  - 2022
U6  - https://doi.org/10.1038/s41598-022-16633-1
SN  - 2045-2322
VL  - 12
IS  - 1
PB  - Nature portfolio
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Merz, Bruno
A1  - Basso, Stefano
A1  - Fischer, Svenja
A1  - Lun, David
A1  - Bloeschl, Guenter
A1  - Merz, Ralf
A1  - Guse, Bjorn
A1  - Viglione, Alberto
A1  - Vorogushyn, Sergiy
A1  - Macdonald, Elena
A1  - Wietzke, Luzie
A1  - Schumann, Andreas
T1  - Understanding heavy tails of flood peak distributions
JF  - Water resources research
N2  - Statistical distributions of flood peak discharge often show heavy tail behavior, that is, extreme floods are more likely to occur than would be predicted by commonly used distributions that have exponential asymptotic behavior. 
This heavy tail behavior may surprise flood managers and citizens, as human intuition tends to expect light tail behavior, and the heaviness of the tails is very difficult to predict, which may lead to unnecessarily high flood damage. 
Despite its high importance, the literature on the heavy tail behavior of flood distributions is rather fragmented. 

In this review, we provide a coherent overview of the processes causing heavy flood tails and the implications for science and practice. 
Specifically, we propose nine hypotheses on the mechanisms causing heavy tails in flood peak distributions related to processes in the atmosphere, the catchment, and the river system. 
We then discuss to which extent the current knowledge supports or contradicts these hypotheses. 
We also discuss the statistical conditions for the emergence of heavy tail behavior based on derived distribution theory and relate them to the hypotheses and flood generation mechanisms. 

We review the degree to which the heaviness of the tails can be predicted from process knowledge and data. Finally, we recommend further research toward testing the hypotheses and improving the prediction of heavy tails.
KW  - extreme events
KW  - flood frequency
KW  - flood risk
KW  - upper tail
Y1  - 2022
U6  - https://doi.org/10.1029/2021WR030506
SN  - 0043-1397
SN  - 1944-7973
VL  - 58
IS  - 6
PB  - American Geophysical Union
CY  - Washington
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  - Farrag, Mostafa
A1  - Brill, Fabio Alexander
A1  - Nguyen, Viet Dung
A1  - Sairam, Nivedita
A1  - Schröter, Kai
A1  - Kreibich, Heidi
A1  - Merz, Bruno
A1  - de Bruijn, Karin M.
A1  - Vorogushyn, Sergiy
T1  - On the role of floodplain storage and hydrodynamic interactions in flood risk estimation
JF  - Hydrological sciences journal = Journal des sciences hydrologiques
N2  - Hydrodynamic interactions, i.e. the floodplain storage effects caused by inundations upstream on flood wave propagation, inundation areas, and flood damage downstream, are important but often ignored in large-scale flood risk assessments. Although new methods considering these effects sometimes emerge, they are often limited to a small or meso scale. In this study, we investigate the role of hydrodynamic interactions and floodplain storage on flood hazard and risk in the German part of the Rhine basin. To do so, we compare a new continuous 1D routing scheme within a flood risk model chain to the piece-wise routing scheme, which largely neglects floodplain storage. The results show that floodplain storage is significant, lowers water levels and discharges, and reduces risks by over 50%. Therefore, for accurate risk assessments, a system approach must be adopted, and floodplain storage and hydrodynamic interactions must carefully be considered.
KW  - hydrodynamic interactions
KW  - derived flood risk analysis
KW  - flood modelling;
KW  - Rhine basin
Y1  - 2022
U6  - https://doi.org/10.1080/02626667.2022.2030058
SN  - 0262-6667
SN  - 2150-3435
VL  - 67
IS  - 4
SP  - 508
EP  - 534
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Inceoglu, Fadil
A1  - Shprits, Yuri
A1  - Heinemann, Stephan G.
A1  - Bianco, Stefano
T1  - Identification of coronal holes on AIA/SDO images using unsupervised machine learning
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - Through its magnetic activity, the Sun governs the conditions in Earth's vicinity, creating space weather events, which have drastic effects on our space- and ground-based technology. 
One of the most important solar magnetic features creating the space weather is the solar wind that originates from the coronal holes (CHs). 
The identification of the CHs on the Sun as one of the source regions of the solar wind is therefore crucial to achieve predictive capabilities. 

In this study, we used an unsupervised machine-learning method, k-means, to pixel-wise cluster the passband images of the Sun taken by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory in 171, 193, and 211 angstrom in different combinations. 

Our results show that the pixel-wise k-means clustering together with systematic pre- and postprocessing steps provides compatible results with those from complex methods, such as convolutional neural networks. 
More importantly, our study shows that there is a need for a CH database where a consensus about the CH boundaries is reached by observers independently. 
This database then can be used as the "ground truth," when using a supervised method or just to evaluate the goodness of the models.
Y1  - 2022
U6  - https://doi.org/10.3847/1538-4357/ac5f43
SN  - 1538-4357
VL  - 930
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Landis, Daji August
A1  - Saikin, Anthony
A1  - Zhelavskaya, Irina
A1  - Drozdov, Alexander
A1  - Aseev, Nikita
A1  - Shprits, Yuri
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  - Shprits, Yuri
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  - Drozdov, Alexander
A1  - Allison, Hayley J.
A1  - Shprits, Yuri
A1  - Usanova, Maria E.
A1  - Saikin, Anthony
A1  - Wang, Dedong
T1  - Depletions of Multi-MeV Electrons and their association to Minima in Phase Space Density
JF  - Geophysical research letters
N2  - Fast-localized electron loss, resulting from interactions with electromagnetic ion cyclotron (EMIC) waves, can produce deepening minima in phase space density (PSD) radial profiles. Here, we perform a statistical analysis of local PSD minima to quantify how readily these are associated with radiation belt depletions. The statistics of PSD minima observed over a year are compared to the Versatile Electron Radiation Belts (VERB) simulations, both including and excluding EMIC waves. The observed minima distribution can only be achieved in the simulation including EMIC waves, indicating their importance in the dynamics of the radiation belts. By analyzing electron flux depletions in conjunction with the observed PSD minima, we show that, in the heart of the outer radiation belt (L* < 5), on average, 53% of multi-MeV electron depletions are associated with PSD minima, demonstrating that fast localized loss by interactions with EMIC waves are a common and crucial process for ultra-relativistic electron populations.
KW  - radiation belts
KW  - EMIC
KW  - VERB
KW  - PSD
Y1  - 2022
U6  - https://doi.org/10.1029/2021GL097620
SN  - 0094-8276
SN  - 1944-8007
VL  - 49
IS  - 8
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Scherbaum, Frank
A1  - Mzhavanadze, Nana
A1  - Rosenzweig, Sebastian
A1  - Müller, Meinard
T1  - Tuning systems of traditional Georgian singing determined from a new corpus of field recordings
JF  - Musicologist
N2  - In this study we examine the tonal organization of the 2016 GVM dataset, a newly-created corpus of high-quality multimedia field recordings of traditional Georgian singing with a focus on Svaneti. For this purpose, we developed a new processing pipeline for the computational analysis of non-western polyphonic music which was subsequently applied to the complete 2016 GVM dataset. 
To evaluate under what conditions a single tuning system is representative of current Svan performance practice, we examined the stability of the obtained tuning systems from an ensemble-, a song-, and a corpus-related perspective. 
Furthermore, we compared the resulting Svan tuning systems with the tuning systems obtained for the Erkomaishvili dataset (Rosenzweig et al., 2020) in the study by Scherbaum et al. (2020). In comparison to a 12-TET (12-tone-equal-temperament) system, the Erkomaishvili and the Svan tuning systems are surprisingly similar. 
Both systems show a strong presence of pure fourths (500 cents) and fifths (700 cents), and 'neutral' thirds (peaking around 350 cents) as well as 'neutral' sixths. 
In addition, the sizes of the melodic and the harmonic seconds in both tuning systems differ systematically from each other, with the size of the harmonic second being systematically larger than the melodic one.
KW  - traditional Georgian music
KW  - tuning
KW  - computational ethnomusicology
Y1  - 2022
U6  - https://doi.org/10.33906/musicologist.1068947
SN  - 2618-5652
VL  - 6
IS  - 2
SP  - 142
EP  - 168
PB  - Trabzon Univ State Conservatory
CY  - Trabzon
ER  - 
TY  - JOUR
A1  - Armstrong, Michael R.
A1  - Radousky, Harry B.
A1  - Austin, Ryan A.
A1  - Tschauner, Oliver
A1  - Brown, Shaughnessy
A1  - Gleason, Arianna E.
A1  - Goldman, Nir
A1  - Granados, Eduardo
A1  - Grivickas, Paulius
A1  - Holtgrewe, Nicholas
A1  - Kroonblawd, Matthew P.
A1  - Lee, Hae Ja
A1  - Lobanov, Sergey S.
A1  - Nagler, Bob
A1  - Nam, Inhyuk
A1  - Prakapenka, Vitali
A1  - Prescher, Clemens
A1  - Reed, Evan J.
A1  - Stavrou, Elissaios
A1  - Walter, Peter
A1  - Goncharov, Alexander F.
A1  - Belof, Jonathan L.
T1  - Highly ordered graphite (HOPG) to hexagonal diamond (lonsdaleite) phase transition observed on picosecond time scales using ultrafast x-ray diffraction
JF  - Journal of applied physics
N2  - The response of rapidly compressed highly oriented pyrolytic graphite (HOPG) normal to its basal plane was investigated at a pressure of & SIM;80 GPa. Ultrafast x-ray diffraction using & SIM;100 fs pulses at the Materials Under Extreme Conditions sector of the Linac Coherent Light Source was used to probe the changes in crystal structure resulting from picosecond timescale compression at laser drive energies ranging from 2.5 to 250 mJ. A phase transformation from HOPG to a highly textured hexagonal diamond structure is observed at the highest energy, followed by relaxation to a still highly oriented, but distorted graphite structure following release. We observe the formation of a highly oriented lonsdaleite within 20 ps, subsequent to compression. This suggests that a diffusionless martensitic mechanism may play a fundamental role in phase transition, as speculated in an early work on this system, and more recent static studies of diamonds formed in impact events. Published by AIP Publishing.
Y1  - 2022
U6  - https://doi.org/10.1063/5.0085297
SN  - 0021-8979
SN  - 1089-7550
VL  - 132
IS  - 5
PB  - AIP Publishing
CY  - Melville
ER  - 
TY  - JOUR
A1  - Blanchard, Ingrid
A1  - Petitgirard, Sylvain
A1  - Laurenz, Vera
A1  - Miyajima, Nobuyoshi
A1  - Wilke, Max
A1  - Rubie, David C.
A1  - Lobanov, Sergey S.
A1  - Hennet, Louis
A1  - Morgenroth, Wolfgang
A1  - Tucoulou, Rémi
A1  - Bonino, Valentina
A1  - Zhao, Xuchao
A1  - Franchi, Ian
T1  - Chemical analysis of trace elements at the nanoscale in samples recovered from laser-heated diamond anvil cell experiments
JF  - Physics and chemistry of minerals
N2  - High pressure and high temperature experiments performed with laser-heated diamond anvil cells (LH-DAC) are being extensively used in geosciences to study matter at conditions prevailing in planetary interiors. Due to the size of the apparatus itself, the samples that are produced are extremely small, on the order of few tens of micrometers. There are several ways to analyze the samples and extract physical, chemical or structural information, using either in situ or ex situ methods. In this paper, we compare two nanoprobe techniques, namely nano-XRF and NanoSIMS, that can be used to analyze recovered samples synthetized in a LH-DAC. With these techniques, it is possible to extract the spatial distribution of chemical elements in the samples. We show the results for several standards and discuss the importance of proper calibration for the acquisition of quantifiable results. We used these two nanoprobe techniques to retrieve elemental ratios of dilute species (few tens of ppm) in quenched experimental molten samples relevant for the formation of the iron-rich core of the Earth. We finally discuss the applications of such probes to constrain the partitioning of trace elements between metal and silicate phases, with a focus on moderately siderophile elements, tungsten and molybdenum.
KW  - NanoSIMS
KW  - Nano-XRF
KW  - Diamond anvil cell
KW  - Focused ion beam
Y1  - 2022
U6  - https://doi.org/10.1007/s00269-022-01193-7
SN  - 0342-1791
SN  - 1432-2021
VL  - 49
IS  - 6
PB  - Springer
CY  - New York
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  - Lück, Erika
A1  - Guillemoteau, Julien
A1  - Tronicke, Jens
A1  - Rummel, Udo
A1  - Hierold, Wilfried
T1  - From point to field scale-indirect monitoring of soil moisture variations at the DWD test site in Falkenberg
JF  - Geoderma : an international journal of soil science
N2  - Information regarding the spatial distribution of soil water content is key in many disciplines and applications including soil and atmospheric sciences, hydrology, and agricultural engineering. 
Thus, within the past decades various experimental methods and strategies have been developed to map spatial variations in soil moisture distribution and to monitor temporal changes. 
Our study examines the combination of electrical resistivity mapping and point observations of soil moisture to infer the spatial and the temporal variability of soil moisture. 
Over a period of around two years, we performed field measurements on six days to collect repeated electrical resistivity mapping data for a nine-hectare test site south-east of Berlin, Germany. 

Permanently installed TDR probes, temporary TDR measurements within permanently installed tubes, and gravimetric measurements using soil samples provided soil moisture data at various selected points. 
In addition, soil analysis and classification results are available for 132 regularly distributed positions up to depths of 1.2 m. 
We compare and link three-dimensional resistivity models obtained via data inversion to soil composition and soil moisture as provided by our point data. 
Both the soil samples and the resistivity models indicate a two-layer medium characterized by a sandy top layer with varying thickness and a loamy bottom soil. 
For all six field campaigns, we observe similar resistivity patterns reflecting the temporally stable influence of soil texture. 

While the overall patterns are stable, the range of resistivity values changes with soil moisture. Finally, to estimate spatial models of soil moisture, we link our soil moisture and resistivity data using empirical petrophysical models relying on a second order polynomial function. 
We observe a mean prediction error for soil moisture of +/-0.034 m3 & BULL; m? 3 using all observation points while we notice that point-specific models further reduce the error. 
Thus, we conclude that our experimental and data analysis strategies represent a reliable approach to establish site-specific models and to estimate three-dimensional moisture distribution including temporal variations.
KW  - earth boundary layer
KW  - electrical conductivity
KW  - electrical resistivity
KW  - near-surface geophysics
KW  - soil moisture at field scale
Y1  - 2022
U6  - https://doi.org/10.1016/j.geoderma.2022.116134
SN  - 0016-7061
SN  - 1872-6259
VL  - 427
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Sieber, Melanie J.
A1  - Wilke, Max
A1  - Appelt, Oona
A1  - Oelze, Marcus
A1  - Koch-Müller, Monika
T1  - Melting relations of Ca-Mg carbonates and trace element signature of carbonate melts up to 9 GPa - a proxy for melting of carbonated mantle lithologies
JF  - European journal of mineralogy
N2  - The most profound consequences of the presence of Ca-Mg carbonates (CaCO3-MgCO3) in the Earth's upper mantle may be to lower the melting temperatures of the mantle and control the melt composition. 
Low-degree partial melting of a carbonate-bearing mantle produces CO2-rich, silica-poor melts compositionally imposed by the melting relations of carbonates.
Thus, understanding the melting relations in the CaCO3-MgCO3 system facilitates the interpretation of natural carbonate-bearing silicate systems. 
We report the melting relations of the CaCO3-MgCO3 system and the partition coefficient of trace elements between carbonates and carbonate melt from experiments at high pressure (6 and 9 GPa) and temperature (1300-1800 degrees C) using a rocking multi-anvil press. In the absence of water, Ca-Mg carbonates are stable along geothermal gradients typical of subducting slabs. 
Ca-Mg carbonates ( similar to Mg0.1-0.9Ca0.9-0.1CO3) partially melt beneath mid-ocean ridges and in plume settings. Ca-Mg carbonates melt incongruently, forming periclase crystals and carbonate melt between 4 and 9 GPa. 

Furthermore, we show that the rare earth element (REE) signature of Group-I kimberlites, namely strong REE fractionation and depletion of heavy REE relative to the primitive mantle, is resembled by carbonate melt in equilibrium with Ca-bearing magnesite and periclase at 6 and 9 GPa. 
This suggests that the dolomite-magnesite join of the CaCO3-MgCO3 system might be useful to approximate the REE signature of carbonate-rich melts parental to kimberlites.
Y1  - 2022
U6  - https://doi.org/10.5194/ejm-34-411-2022
SN  - 0935-1221
SN  - 1617-4011
VL  - 34
IS  - 5
SP  - 411
EP  - 424
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Jia, Zeyu
A1  - Lipus, Daniel
A1  - Bartholomaeus, Alexander
A1  - Burckhardt, Oliver
A1  - Sondermann, Megan
A1  - Wagner, Dirk
A1  - Kallmeyer, Jens
T1  - Metagenome-assembled genome of a putative methanogenic Methanosarcina sp. strain enriched from terrestrial high-CO2 subsurface sediments
JF  - Microbiology Resource Announcements
N2  - A metagenome-assembled genome (MAG), named Methanosarcina sp. strain ERenArc_MAG2, was obtained from a 3-month-old H-2/CO2 atmosphere enrichment culture, originally inoculated with 60-m deep drill core sediment collected from the tectonic Eger Rift terrestrial subsurface. 
Annotation of the recovered draft genome revealed putative archaeal methanogenesis genes in the deep biosphere. 
A metagenome-assembled genome (MAG), named Methanosarcina sp. strain ERenArc_MAG2, was obtained from a 3-month-old H-2/CO2 atmosphere enrichment culture, originally inoculated with 60-m deep drill core sediment collected from the tectonic Eger Rift terrestrial subsurface. 
Annotation of the recovered draft genome revealed putative archaeal methanogenesis genes in the deep biosphere.
Y1  - 2022
U6  - https://doi.org/10.1128/mra.01039-22
SN  - 2576-098X
VL  - 11
IS  - 12
PB  - American Society for Microbiology
CY  - Washington
ER  - 
TY  - JOUR
A1  - Dahm, Torsten
A1  - Hainzl, Sebastian
T1  - A Coulomb stress response model for time-dependent earthquake forecasts
JF  - Journal of geophysical research : Solid earth
N2  - Seismicity models are probabilistic forecasts of earthquake rates to support seismic hazard assessment. 
Physics-based models allow extrapolating previously unsampled parameter ranges and enable conclusions on underlying tectonic or human-induced processes. 
The Coulomb Failure (CF) and the rate-and-state (RS) models are two widely used physics-based seismicity models both assuming pre-existing populations of faults responding to Coulomb stress changes. 
The CF model depends on the absolute Coulomb stress and assumes instantaneous triggering if stress exceeds a threshold, while the RS model only depends on stress changes. 
Both models can predict background earthquake rates and time-dependent stress effects, but the RS model with its three independent parameters can additionally explain delayed aftershock triggering. 

This study introduces a modified CF model where the instantaneous triggering is replaced by a mean time-to-failure depending on the absolute stress value. 
For the specific choice of an exponential dependence on stress and a stationary initial seismicity rate, we show that the model leads to identical results as the RS model and reproduces the Omori-Utsu relation for aftershock decays as well stress-shadowing effects. 
Thus, both CF and RS models can be seen as special cases of the new model. However, the new stress response model can also account for subcritical initial stress conditions and alternative functions of the mean time-to-failure depending on the problem and fracture mode.
KW  - seismicity
KW  - physics based model
KW  - earthquake physics
Y1  - 2022
U6  - https://doi.org/10.1029/2022JB024443
SN  - 2169-9313
SN  - 2169-9356
VL  - 127
IS  - 9
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  - Kaboth-Bahr, Stefanie
A1  - Bahr, André
A1  - Zeeden, Christian
A1  - Yamoah, Kweku A.
A1  - Lone, Mahjoor Ahmad
A1  - Chuang, Chih-Kai
A1  - Löwemark, Ludvig
A1  - Wei, Kuo-Yen
T1  - A tale of shifting relations
BT  - East Asian summer and winter monsoon variability during the Holocene
JF  - Scientific Reports
N2  - Understanding the dynamics between the East Asian summer (EASM) and winter monsoon (EAWM) is needed to predict their variability under future global warming scenarios. Here, we investigate the relationship between EASM and EAWM as well as the mechanisms driving their variability during the last 10,000 years by stacking marine and terrestrial (non-speleothem) proxy records from the East Asian realm. This provides a regional and proxy independent signal for both monsoonal systems. The respective signal was subsequently analysed using a linear regression model. We find that the phase relationship between EASM and EAWM is not time-constant and significantly depends on orbital configuration changes. In addition, changes in the Atlantic Meridional Overturning circulation, Arctic sea-ice coverage, El Niño-Southern Oscillation and Sun Spot numbers contributed to millennial scale changes in the EASM and EAWM during the Holocene. We also argue that the bulk signal of monsoonal activity captured by the stacked non-speleothem proxy records supports the previously argued bias of speleothem climatic archives to moisture source changes and/or seasonality.
KW  - Environmental sciences
KW  - Ocean sciences
KW  - Solid Earth sciences
Y1  - 2020
U6  - https://doi.org/10.1038/s41598-021-85444-7
SN  - 2045-2322
VL  - 11
PB  - Macmillan Publishers Limited, part of Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Borchardt, Sven
A1  - Trauth, Martin H.
T1  - Erratum to: Borchardt, Sven, Trauth, Martin H.: Remotely-sensed evapotranspiration estimates for an improved hydrological modeling of the early Holocene mega-lake Suguta, northern Kenya Rift. - (Palaeogeography, Palaeoclimatology, Palaeoecology. - Volumes 361–362 (2012), S. 14 – 20. - doi.org/10.1016/j.palaeo.2012.07.009)
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
Y1  - 2021
U6  - https://doi.org/10.1016/j.palaeo.2019.109540
SN  - 0031-0182
SN  - 1872-616X
VL  - 571
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Trauth, Martin H.
T1  - Spectral analysis in quaternary sciences
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Spectral analysis is a technique of time-series analysis that decomposes signals into linear combinations of harmonic components. Rooted in the 19th century, spectral analysis gained popularity in palaeoclimatology since the early 1980s. This was partly due to the availability of long time series of past climates, but also the development of new, partly adapted methods and the increasing spread of affordable personal computers. This paper reviews the most important methods of spectral analysis for palaeoclimate time series and discusses the prerequisites for their application as well as advantages and disadvantages. The paper also offers an overview of suitable software, as well as computer code for using the methods on synthetic examples.
KW  - Spectral analysis
KW  - Paleoclimate
KW  - Orbital forcing
KW  - MATLAB
Y1  - 2021
U6  - https://doi.org/10.1016/j.quascirev.2021.107157
SN  - 0277-3791
SN  - 1873-457X
VL  - 270
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Steinberg, Andreas
A1  - Vasyura-Bathke, Hannes
A1  - Gaebler, Peter Jost
A1  - Ohrnberger, Matthias
A1  - Ceranna, Lars
T1  - Estimation of seismic moment tensors using variational inference machine learning
JF  - Journal of geophysical research : Solid earth
N2  - We present an approach for rapidly estimating full moment tensors of earthquakes and their parameter uncertainties based on short time windows of recorded seismic waveform data by considering deep learning of Bayesian Neural Networks (BNNs). The individual neural networks are trained on synthetic seismic waveform data and corresponding known earthquake moment-tensor parameters. A monitoring volume has been predefined to form a three-dimensional grid of locations and to train a BNN for each grid point. Variational inference on several of these networks allows us to consider several sources of error and how they affect the estimated full moment-tensor parameters and their uncertainties. In particular, we demonstrate how estimated parameter distributions are affected by uncertainties in the earthquake centroid location in space and time as well as in the assumed Earth structure model. We apply our approach as a proof of concept on seismic waveform recordings of aftershocks of the Ridgecrest 2019 earthquake with moment magnitudes ranging from Mw 2.7 to Mw 5.5. Overall, good agreement has been achieved between inferred parameter ensembles and independently estimated parameters using classical methods. Our developed approach is fast and robust, and therefore, suitable for down-stream analyses that need rapid estimates of the source mechanism for a large number of earthquakes.
KW  - seismology
KW  - machine learning
KW  - earthquake source
KW  - moment tensor
KW  - full
KW  - waveform
Y1  - 2021
U6  - https://doi.org/10.1029/2021JB022685
SN  - 2169-9313
SN  - 2169-9356
VL  - 126
IS  - 10
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kaboth-Bahr, Stefanie
A1  - Bahr, André
A1  - Stepanek, Christian
A1  - Catunda, Maria Carolina Amorim
A1  - Karas, Cyrus
A1  - Ziegler, Martin
A1  - García-Gallardo, Ángela
A1  - Grunert, Patrick
T1  - Mediterranean heat injection to the North Atlantic delayed the intensification of Northern Hemisphere glaciations
JF  - Communications Earth & Environment
N2  - The intensification of Northern Hemisphere glaciations at the end of the Pliocene epoch marks one of the most substantial climatic shifts of the Cenozoic. Despite global cooling, sea surface temperatures in the high latitude North Atlantic Ocean rose between 2.9–2.7 million years ago. Here we present sedimentary geochemical proxy data from the Gulf of Cadiz to reconstruct the variability of Mediterranean Outflow Water, an important heat source to the North Atlantic. We find evidence for enhanced production of Mediterranean Outflow from the mid-Pliocene to the late Pliocene which we infer could have driven a sub-surface heat channel into the high-latitude North Atlantic. We then use Earth System Models to constrain the impact of enhanced Mediterranean Outflow production on the northward heat transport in the North Atlantic. In accord with the proxy data, the numerical model results support the formation of a sub-surface channel that pumped heat from the subtropics into the high latitude North Atlantic. We further suggest that this mechanism could have delayed ice sheet growth at the end of the Pliocene.
Y1  - 2021
U6  - https://doi.org/10.1038/s43247-021-00232-5
SN  - 2662-4435
SP  - 1
EP  - 9
PB  - Springer Nature
CY  - London
ER  - 
TY  - JOUR
A1  - Brendel, Nina
A1  - Matzner, Nils
A1  - Menzel, Max-Peter
T1  - Geographisches Gezwitscher – Analyse von Twitter-Daten als Methode im GW-Unterricht
JF  - GW-Unterricht
N2  - Soziale Medien sind ein wesentlicher Bestandteil des Alltags von Schüler*innen und gleichzeitig zunehmend wichtig in Wirtschaft, Politik und Wissenschaft. Am Beispiel von Twitter zeigt dieser Beitrag, dass soziale Medien im Unterricht auch für die Beantwortung geographischer Fragestellungen verwendet werden können. Hierfür eignen sich Twitter-Daten aufgrund ihrer Georeferenzierung und weiterer interessanter Inhalte besonders. Der Beitrag gibt einen Überblick über die Verwendung von Twitter für sozialwissenschaftliche und humangeographische Fragestellungen und reflektiert die Nutzung von Twitter im Unterricht. Für die Unterrichtspraxis werden Beispiele zu den Themen Braunkohle, Flutereignisse und Raumwahrnehmungen sowie Anleitungen zur Auswertung, Anwendung und Reflexion von Twitter-Analysen vorgestellt.
KW  - Twitter
KW  - Soziale Medien
KW  - Forschungsmethodik
KW  - Unterrichtsmethoden
Y1  - 2021
U6  - https://doi.org/10.1553/gw-unterricht164s72
SN  - 2414-4169
SP  - 72
EP  - 85
PB  - Verlag der Österreichischen Akademie der Wissenschaften
CY  - Wien
ER  - 
TY  - JOUR
A1  - Saki, Adel
A1  - Miri, Mirmohammad
A1  - Oberhänsli, Roland
T1  - Pseudosection modelling of the Precambrian meta-pelites from the Poshtuk area, NW Iran
JF  - Periodico di mineralogia : an international journal of mineralogy, crystallography, geochemistry, ore deposits, petrology, volcanology and applied topics on environment, archaeometry and cultural heritage / Dipartimento di Scienze della Terra, Università degli Studi di Roma la Sapienza
N2  - Precambrian meta-pelites of the Poshtuk area in northwest Iran contain the prograde mineral assemblage staurolite-garnet-chloritoid-muscovite-biotite that was replaced by the assemblage garnet-staurolite-chlorite-muscovite-biotite at peak metamorphic condition. 
Whole-rock compositions reveal that high Fe, Al and Mn contents of their protolith rendered them prone to form these assemblages. Pseudosections calculated in KFMASH, MnKFMASH, and MnNCKFMASHO systems were used to investigate the P-T evolution of the samples. They clearly show the significant effect of MnO on the stability of the chloritoid-bearing assemblages and the formation of garnet through consumption of chlorite and chloritoid. The pseudosection in a T- aH(2)O diagram shows that the studied assemblage could be stable only at a(H2O)>0.8. X-Mg isopleths for garnet and biotite point to peak P-T conditions of about 3.75 kbar and 575 degrees C. Chloritoid stability is overstepped with such conditions. This can be attributed to thermal perturbation due to plutonism. It is concluded, metamorphism was primarily controlled by advective heat from magmatic intrusions in the Poshtuk area. The Precambrian basement complexes were extensively overprinted by the Pan-African Orogeny as well as younger magmatic and metamorphic activities associated to Alpine Orogeny during convergence of Arabian and Eurasian plate.
KW  - meta-pelites
KW  - pseudosection
KW  - chloritoid stability
KW  - Precambrain
KW  - Poshtuk
Y1  - 2021
U6  - https://doi.org/10.13133/2239-1002/16632
SN  - 0369-8963
VL  - 90
IS  - 3
SP  - 325
EP  - 340
PB  - Bardi
CY  - Roma
ER  - 
TY  - JOUR
A1  - Blanchard, Ingrid
A1  - Abeykoon, Sumith
A1  - Frost, Daniel J.
A1  - Rubie, David C.
T1  - Sulfur content at sulfide saturation of peridotitic melt at upper mantle conditions
JF  - American mineralogist : an international journal of earth and planetary materials / Mineralogical Society of America
N2  - The concentration of sulfur that can be dissolved in a silicate liquid is of fundamental importance because it is closely associated with several major Earth-related processes. Considerable effort has been made to understand the interplay between the effects of silicate melt composition and its capac-ity to retain sulfur, but the dependence on pressure and temperature is mostly based on experiments performed at pressures and temperatures below 6 GPa and 2073 K. Here we present a study of the effects of pressure and temperature on sulfur content at sulfide saturation of a peridotitic liquid. We performed 14 multi-anvil experiments using a peridotitic starting composition, and we produced 25 new measurements at conditions ranging from 7 to 23 GPa and 2173 to 2623 K. We analyzed the recovered samples using both electron microprobe and laser ablation ICP-MS. We compiled our data together with previously published data that were obtained at lower P-T conditions and with various silicate melt compositions. We present a new model based on this combined data set that encompasses the entire range of upper mantle pressure-temperature conditions, along with the effect of a wide range of silicate melt compositions. Our findings are consistent with earlier work based on extrapolation from lower-pressure and lower-temperature experiments and show a decrease of sulfur content at sulfide saturation (SCSS) with increasing pressure and an increase of SCSS with increasing temperature. We have extrapolated our results to pressure-temperature conditions of the Earth's primitive magma ocean, and show that FeS will exsolve from the molten silicate and can effectively be extracted to the core by a process that has been termed the "Hadean Matte." We also discuss briefly the implications of our results for the lunar magma ocean.
KW  - Peridotitic melts
KW  - sulfur solubility
KW  - high pressure
KW  - high temperature
KW  - magma ocean
Y1  - 2021
U6  - https://doi.org/10.2138/am-2021-7649
SN  - 0003-004X
SN  - 1945-3027
VL  - 106
IS  - 11
SP  - 1835
EP  - 1843
PB  - Mineralogical Society of America
CY  - Washington, DC [u.a.]
ER  - 
TY  - JOUR
A1  - Müller, Daniela
A1  - Tjallingii, Rik
A1  - Plociennik, Mateusz
A1  - Luoto, Tomi P.
A1  - Kotrys, Bartosz
A1  - Plessen, Birgit
A1  - Ramisch, Arne
A1  - Schwab, Markus Julius
A1  - Blaszkiewicz, Miroslaw
A1  - Slowinski, Michal
A1  - Brauer, Achim
T1  - New insights into lake responses to rapid climate change
BT  - The Younger Dryas in Lake Goscia(z) over dot, central Poland
JF  - Boreas
N2  - The sediment profile from Lake Goscia(z) over dot in central Poland comprises a continuous, seasonally resolved and exceptionally well-preserved archive of the Younger Dryas (YD) climate variation. This provides a unique opportunity for detailed investigation of lake system responses during periods of rapid climate cooling (YD onset) and warming (YD termination). The new varve record of Lake Goscia(z) over dot presented here spans 1662 years from the late Allerod (AL) to the early Preboreal (PB). Microscopic varve counting provides an independent chronology with a YD duration of 1149+14/-22 years, which confirms previous results of 1140 +/- 40 years. We link stable oxygen isotopes and chironomid-based air temperature reconstructions with the response of various geochemical and varve microfacies proxies especially focusing on the onset and termination of the YD. Cooling at the YD onset lasted similar to 180 years, which is about a century longer than the terminal warming that was completed in similar to 70 years. During the AL/YD transition, environmental proxy data lagged the onset of cooling by similar to 90 years and revealed an increase of lake productivity and internal lake re-suspension as well as slightly higher detrital sediment input. In contrast, rapid warming and environmental changes during the YD/PB transition occurred simultaneously. However, initial changes such as declining diatom deposition and detrital input occurred already a few centuries before the rapid warming at the YD/PB transition. These environmental changes likely reflect a gradual increase in summer air temperatures already during the YD. Our data indicate complex and differing environmental responses to the major climate changes related to the YD, which involve different proxy sensitivities and threshold processes.
KW  - central Poland
KW  - Younger Dryas
KW  - sedimentation pattern
KW  - lake sediments
Y1  - 2021
U6  - https://doi.org/10.23689/fidgeo-4033
SN  - 0300-9483
SN  - 1502-3885
VL  - 50
IS  - 2
SP  - 535
EP  - 555
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Cheng, Chaojie
A1  - Milsch, Harald
T1  - Hydromechanical investigations on the self-propping potential of fractures in tight sandstones
JF  - Rock mechanics and rock engineering
N2  - The hydromechanical properties of single self-propping fractures under stress are of fundamental interest for fractured-rock hydrology and a large number of geotechnical applications. This experimental study investigates fracture closure and hydraulic aperture changes of displaced tensile fractures, aligned tensile fractures, and saw-cut fractures for two types of sandstone (i.e., Flechtinger and Fontainebleau) with contrasting mechanical properties, cycling confining pressure between 5 and 30 MPa. Emphasis is placed on how surface roughness, fracture wall offset, and the mechanical properties of the contact asperities affect the self-propping potential of these fractures under normal stress. A relative fracture wall displacement can significantly increase fracture aperture and hydraulic conductivity, but the degree of increase strongly depends on the fracture surface roughness. For smooth fractures, surface roughness remains scale-independent as long as the fracture area is larger than a roll-off wavelength and thus any further displacement does not affect fracture aperture. For rough tensile fractures, these are self-affine over a larger scale so that an incremental fracture wall offset likely leads to an increase in fracture aperture. X-ray microtomography of the fractures indicates that the contact area ratio of the tensile fractures after the confining pressure cycle inversely correlates with the fracture wall offset yielding values in the range of about 3-25%, depending, first, on the respective surface roughness and, second, on the strength of the asperities in contact. Moreover, the contact asperities mainly occur isolated and tend to be preferentially oriented in the direction perpendicular to the fracture wall displacement which, in turn, may induce flow anisotropy. This, overall, implies that relatively harder sedimentary rocks have a higher self-propping potential for sustainable fluid flow through fractures in comparison to relatively soft rocks when specific conditions regarding surface roughness and fracture wall offset are met.
KW  - Self-propping fracture
KW  - Mechanical aperture
KW  - Hydraulic aperture
KW  - Normal
KW  - stress
KW  - Fracture wall offset
KW  - Surface roughness
Y1  - 2021
U6  - https://doi.org/10.1007/s00603-021-02500-4
SN  - 0723-2632
SN  - 1434-453X
VL  - 54
IS  - 10
SP  - 5407
EP  - 5432
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Heckenbach, Esther Lina
A1  - Brune, Sascha
A1  - Glerum, Anne C.
A1  - Bott, Judith
T1  - Is there a speed limit for the thermal steady-state assumption in continental rifts?
JF  - Geochemistry, geophysics, geosystems : G 3 ; an electronic journal of the earth sciences
N2  - The lithosphere is often assumed to reside in a thermal steady-state when quantitatively describing the temperature distribution in continental interiors and sedimentary basins, but also at active plate boundaries. Here, we investigate the applicability limit of this assumption at slowly deforming continental rifts. To this aim, we assess the tectonic thermal imprint in numerical experiments that cover a range of realistic rift configurations. For each model scenario, the deviation from thermal equilibrium is evaluated. This is done by comparing the transient temperature field of every model to a corresponding steady-state model with an identical structural configuration. We find that the validity of the thermal steady-state assumption strongly depends on rift type, divergence velocity, sampling location, and depth within the rift. Maximum differences between transient and steady-state models occur in narrow rifts, at the rift sides, and if the extension rate exceeds 0.5-2 mm/a. Wide rifts, however, reside close to thermal steady-state even for high extension velocities. The transient imprint of rifting appears to be overall negligible for shallow isotherms with a temperature less than 100 degrees C. Contrarily, a steady-state treatment of deep crustal isotherms leads to an underestimation of crustal temperatures, especially for narrow rift settings. Thus, not only relatively fast rifts like the Gulf of Corinth, Red Sea, and Main Ethiopian Rift, but even slow rifts like the Kenya Rift, Rhine Graben, and Rio Grande Rift must be expected to feature a pronounced transient component in the temperature field and to therefore violate the thermal steady-state assumption for deeper crustal isotherms.
KW  - basin analysis
KW  - geodynamics
KW  - numerical modeling
KW  - rifting
KW  - thermal
KW  - modeling
Y1  - 2021
U6  - https://doi.org/10.1029/2020GC009577
SN  - 1525-2027
VL  - 22
IS  - 3
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - De Lucia, Marco
A1  - Kühn, Michael
T1  - DecTree v1.0-chemistry speedup in reactive transport simulations
BT  - purely data-driven and physics-based surrogates
JF  - Geoscientific model development : an interactive open access journal of the European Geosciences Union
N2  - The computational costs associated with coupled reactive transport simulations are mostly due to the chemical subsystem: replacing it with a pre-trained statistical surrogate is a promising strategy to achieve decisive speedups at the price of small accuracy losses and thus to extend the scale of problems which can be handled. We introduce a hierarchical coupling scheme in which "full-physics" equation-based geochemical simulations are partially replaced by surrogates. Errors in mass balance resulting from multivariate surrogate predictions effectively assess the accuracy of multivariate regressions at runtime: inaccurate surrogate predictions are rejected and the more expensive equation-based simulations are run instead. Gradient boosting regressors such as XGBoost, not requiring data standardization and being able to handle Tweedie distributions, proved to be a suitable emulator. Finally, we devise a surrogate approach based on geochemical knowledge, which overcomes the issue of robustness when encountering previously unseen data and which can serve as a basis for further development of hybrid physics-AI modelling.
Y1  - 2021
U6  - https://doi.org/10.5194/gmd-14-4713-2021
SN  - 1991-959X
SN  - 1991-9603
VL  - 14
IS  - 7
SP  - 4713
EP  - 4730
PB  - Copernicus
CY  - Göttingen
ER  - 
TY  - JOUR
A1  - Nicoli, Gautier
A1  - Ferrero, Silvio
T1  - Nanorocks, volatiles and plate tectonics
JF  - Geoscience frontiers
N2  - The global geological volatile cycle (H, C, N) plays an important role in the long term self-regulation of the Earth system. However, the complex interaction between its deep, solid Earth components (i.e. crust and mantle), Earth's fluid envelopes (i.e. atmosphere and hydrosphere) and plate tectonic processes is a subject of ongoing debate. In this study we want to draw attention to how the presence of primary melt (MI) and fluid (FI) inclusions in high-grade metamorphic minerals could help constrain the crustal component of the volatile cycle. To that end, we review the distribution of MI and FI throughout Earth's history, from ca. 3.0 Ga ago up to the present day. We argue that the lower crust might constitute an important, long-term, volatile storage unit, capable to influence the composition of the surface envelopes through the mean of weathering, crustal thickening, partial melting and crustal assimilation during volcanic activity. Combined with thermodynamic modelling, our compilation indicates that periods of well-established plate tectonic regimes at <0.85 Ga and 1.7-2.1 Ga, might be more prone to the reworking of supracrustal lithologies and the storage of volatiles in the lower crust. Such hypothesis has implication beyond the scope of metamorphic petrology as it potentially links geodynamic mechanisms to habitable surface conditions. MI and FI in metamorphic crustal rocks then represent an invaluable archive to assess and quantify the co-joint evolution of plate tectonics and Earth's external processes. (C) 2021 China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
KW  - Nanorocks
KW  - Plate tectonics
KW  - Volatiles
KW  - Lower crust
Y1  - 2021
U6  - https://doi.org/10.1016/j.gsf.2021.101188
SN  - 1674-9871
VL  - 12
IS  - 5
PB  - Amsterdam [u.a.]
CY  - Elsevier
ER  - 
TY  - JOUR
A1  - Wang, Lei
A1  - Rybacki, Erik
A1  - Bonnelye, Audrey
A1  - Bohnhoff, Marco
A1  - Dresen, Georg
T1  - Experimental investigation on static and dynamic bulk moduli of dry and fluid-saturated porous sandstones
JF  - Rock mechanics and rock engineering
N2  - Knowledge of pressure-dependent static and dynamic moduli of porous reservoir rocks is of key importance for evaluating geological setting of a reservoir in geo-energy applications. We examined experimentally the evolution of static and dynamic bulk moduli for porous Bentheim sandstone with increasing confining pressure up to about 190 MPa under dry and water-saturated conditions. The static bulk moduli (K-s) were estimated from stress-volumetric strain curves while dynamic bulk moduli (K-d) were derived from the changes in ultrasonic P- and S- wave velocities (similar to 1 MHz) along different traces, which were monitored simultaneously during the entire deformation. In conjunction with published data of other porous sandstones (Berea, Navajo and Weber sandstones), our results reveal that the ratio between dynamic and static bulk moduli (K-d/K-s) reduces rapidly from about 1.5 - 2.0 at ambient pressure to about 1.1 at high pressure under dry conditions and from about 2.0 - 4.0 to about 1.5 under water-saturated conditions, respectively. We interpret such a pressure-dependent reduction by closure of narrow (compliant) cracks, highlighting thatK(d)/K(s)is positively correlated with the amount of narrow cracks. Above the crack closure pressure, where equant (stiff) pores dominate the void space,K-d/K(s)is almost constant. The enhanced difference between dynamic and static bulk moduli under water saturation compared to dry conditions is possibly caused by high pore pressure that is locally maintained if measured using high-frequency ultrasonic wave velocities. In our experiments, the pressure dependence of dynamic bulk modulus of water-saturated Bentheim sandstone at effective pressures above 5 MPa can be roughly predicted by both the effective medium theory (Mori-Tanaka scheme) and the squirt-flow model. Static bulk moduli are found to be more sensitive to narrow cracks than dynamic bulk moduli for porous sandstones under dry and water-saturated conditions.
KW  - Porous sandstone
KW  - Static bulk modulus
KW  - Dynamic bulk modulus
KW  - Narrow
KW  - (compliant) cracks
KW  - Equant (stiff) pores
Y1  - 2020
U6  - https://doi.org/10.1007/s00603-020-02248-3
SN  - 0723-2632
SN  - 1434-453X
VL  - 54
IS  - 1
SP  - 129
EP  - 148
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Roud, Sophie
A1  - Wack, Michael Richard
A1  - Gilder, Stuart A.
A1  - Kudriavtseva, Anna
A1  - Sobel, Edward
T1  - Miocene to early pleistocene depositional history and tectonic evolution of the Issyk-Kul Basin, Central Tian Shan
JF  - Geochemistry, geophysics, geosystems : G 3 ; an electronic journal of the earth sciences
N2  - The Issyk-Kul Basin (Kyrgyzstan), situated in the central Tian Shan Mountains, hosts the largest and deepest mountain lake in Central Asia. Erosion of the surrounding Terskey and Kungey ranges led to the accumulation of up to 4 km of sediment in the adjacent depression. Creation of the basin from regional shortening and uplift likely initiated around the Oligocene-Miocene, yet precise age control is sparse. To better understand the timing of these processes, we obtained magnetostratigraphic age constraints on fossil-poor, fluvio-lacustrine sediments exposed south of Lake Issyk-Kul, that agree well with previous age constraints of the equivalent strata outside the Issyk-Kul Basin. Two 500-650 m thick sections comprised mainly of Chu Group sediments were dated at 6.3-2.8 Ma and 7.0-2.4 Ma (late Miocene to early Pleistocene). Together with reinterpreted magnetostratigraphic constraints from underlying strata, we find that syn-tectonic deposition commenced at similar to 22 Ma with average sedimentation rates <10 cm/ka. Sedimentation rates increased to 10-30 cm/ka at 7 Ma, concurrent with accelerated uplift in the Terskey Range to the south. A deformation event in one section (Kaji-Say) between 5 and 3 Ma together with concurrent shifts of depositional centers throughout the basin signal the onset of substantial uplift of the Kungey Range to the north at similar to 5 Ma. This uplift and deformation transformed the Issyk-Kul area into a closed basin that facilitated the formation of a deep lake. Lacustrine facies deposited around 3 Ma mark the existence of Lake Issyk-Kul by that time.
KW  - Central Asia
KW  - Lake Issyk‐ Kul
KW  - magnetostratigraphy
KW  - Neogene
KW  - Tian
KW  - Shan
Y1  - 2021
U6  - https://doi.org/10.1029/2020GC009556
SN  - 1525-2027
VL  - 22
IS  - 4
PB  - Wiley
CY  - Hoboken, NJ
ER  - 
TY  - JOUR
A1  - Hennig, Theresa
A1  - Kühn, Michael
T1  - Surrogate model for multi-component diffusion of Uranium through Opalinus Clay on the host rock scale
JF  - Applied Sciences : open access journal
N2  - Multi-component (MC) diffusion simulations enable a process based and more precise approach to calculate transport and sorption compared to the commonly used single-component (SC) models following Fick's law. The MC approach takes into account the interaction of chemical species in the porewater with the diffuse double layer (DDL) adhering clay mineral surfaces. We studied the shaly, sandy and carbonate-rich facies of the Opalinus Clay. High clay contents dominate diffusion and sorption of uranium. The MC simulations show shorter diffusion lengths than the SC models due to anion exclusion from the DDL. This hampers diffusion of the predominant species CaUO2(CO3)32-. On the one side, species concentrations and ionic strengths of the porewater and on the other side surface charge of the clay minerals control the composition and behaviour of the DDL. For some instances, it amplifies the diffusion of uranium. We developed a workflow to transfer computationally intensive MC simulations to SC models via calibrated effective diffusion and distribution coefficients. Simulations for one million years depict maximum uranium diffusion lengths between 10 m and 35 m. With respect to the minimum requirement of a thickness of 100 m, the Opalinus Clay seems to be a suitable host rock for nuclear waste repositories.
KW  - facies
KW  - uranium speciation
KW  - sorption
KW  - reactive transport
KW  - heterogeneity
KW  - PHREEQC
KW  - Mont Terri
KW  - repository far-field
Y1  - 2021
U6  - https://doi.org/10.3390/app11020786
SN  - 2076-3417
VL  - 11
IS  - 2
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Tranter, Morgan Alan
A1  - De Lucia, Marco
A1  - Kühn, Michael
T1  - Numerical investigation of barite scaling kinetics in fractures
JF  - Geothermics : an international journal of geothermal research and its applications
N2  - Barite stands out as one of the most ubiquitous scaling agents in deep geothermal systems, responsible for irreversible efficiency loss. Due to complex parameter interplay, it is imperative to utilise numerical simulations to investigate temporal and spatial precipitation effects. A one-dimensional reactive transport model is set up with heterogeneous nucleation and crystal growth kinetics. In line with geothermal systems in the North German Basin, the following parameters are considered in a sensitivity analysis: temperature (25 to 150 degrees C), pore pressure (10 to 50 MPa), fracture aperture (10(-4) to 10(-2) m), flow velocity (10(-3) to 10(0) m s(-1)), molar volume (50.3 to 55.6 cm(3) mol(-1)), contact angle for heterogeneous nucleation (0 degrees to 180 degrees), interfacial tension (0.07 to 0.134 J m(-2)), salinity (0.1 to 1.5 mol kgw(-1) NaCl), pH (5 to 7), and supersaturation ratio (1 to 30). Nucleation and consequently crystal growth can only begin if the threshold supersaturation is exceeded, therefore contact angle and interfacial tension are the most sensitive in terms of precipitation kinetics. If nucleation has occurred, crystal growth becomes the dominant process, which is mainly controlled by fracture aperture. Results show that fracture sealing takes place within months (median 33 days) and the affected range can be on the order of tens of metres (median 10 m). The presented models suggest that barite scaling must be recognised as a serious threat if the supersaturation threshold is exceeded, in which case, large fracture apertures could help to minimise kinetic rates. The models further are of use for adjusting the fluid injection temperature.
KW  - Geothermal
KW  - Fracture sealing
KW  - Reactive transport
KW  - Geochemical modelling
KW  - Crystal nucleation
KW  - PHREEQC
Y1  - 2021
SN  - 0375-6505
SN  - 1879-3576
VL  - 91
PB  - Elsevier
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Pan, Mengdi
A1  - Schicks, Judith M.
T1  - Influence of gas supply changes on the formation process of complex mixed gas hydrates
JF  - Molecules : a journal of synthetic chemistry and natural product chemistry / Molecular Diversity Preservation International
N2  - Natural gas hydrate occurrences contain predominantly methane; however, there are increasing reports of complex mixed gas hydrates and coexisting hydrate phases. Changes in the feed gas composition due to the preferred incorporation of certain components into the hydrate phase and an inadequate gas supply is often assumed to be the cause of coexisting hydrate phases. This could also be the case for the gas hydrate system in Qilian Mountain permafrost (QMP), which is mainly controlled by pores and fractures with complex gas compositions. This study is dedicated to the experimental investigations on the formation process of mixed gas hydrates based on the reservoir conditions in QMP. Hydrates were synthesized from water and a gas mixture under different gas supply conditions to study the effects on the hydrate formation process. In situ Raman spectroscopic measurements and microscopic observations were applied to record changes in both gas and hydrate phase over the whole formation process. The results demonstrated the effects of gas flow on the composition of the resulting hydrate phase, indicating a competitive enclathration of guest molecules into the hydrate lattice depending on their properties. Another observation was that despite significant changes in the gas composition, no coexisting hydrate phases were formed.
KW  - mixed gas hydrates
KW  - hydrate formation process
KW  - coexisting phases
KW  - in
KW  - situ Raman spectroscopy
KW  - gas supply conditions
Y1  - 2021
U6  - https://doi.org/10.3390/molecules26103039
SN  - 1420-3049
VL  - 26
IS  - 10
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Wetzel, Maria
A1  - Kempka, Thomas
A1  - Kühn, Michael
T1  - Diagenetic trends of synthetic reservoir sandstone properties assessed by digital rock physics
JF  - Minerals
N2  - Quantifying interactions and dependencies among geometric, hydraulic and mechanical properties of reservoir sandstones is of particular importance for the exploration and utilisation of the geological subsurface and can be assessed by synthetic sandstones comprising the microstructural complexity of natural rocks. In the present study, three highly resolved samples of the Fontainebleau, Berea and Bentheim sandstones are generated by means of a process-based approach, which combines the gravity-driven deposition of irregularly shaped grains and their diagenetic cementation by three different schemes. The resulting evolution in porosity, permeability and rock stiffness is examined and compared to the respective micro-computer tomographic (micro-CT) scans. The grain contact-preferential scheme implies a progressive clogging of small throats and consequently produces considerably less connected and stiffer samples than the two other schemes. By contrast, uniform quartz overgrowth continuously alters the pore space and leads to the lowest elastic properties. The proposed stress-dependent cementation scheme combines both approaches of contact-cement and quartz overgrowth, resulting in granulometric, hydraulic and elastic properties equivalent to those of the respective micro-CT scans, where bulk moduli slightly deviate by 0.8%, 4.9% and 2.5% for the Fontainebleau, Berea and Bentheim sandstone, respectively. The synthetic samples can be further altered to examine the impact of mineral dissolution or precipitation as well as fracturing on various petrophysical correlations, which is of particular relevance for numerous aspects of a sustainable subsurface utilisation.
KW  - digital core reconstruction
KW  - micro-CT scan
KW  - pore-scale
KW  - cementation
KW  - permeability-porosity relationship
KW  - elastic rock properties
KW  - numerical
KW  - simulation
Y1  - 2021
U6  - https://doi.org/10.3390/min11020151
SN  - 2075-163X
VL  - 11
IS  - 2
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Steding, Svenja
A1  - Kempka, Thomas
A1  - Kühn, Michael
T1  - How insoluble inclusions and intersecting layers affect the leaching process within potash seams
JF  - Applied Sciences : open access journal
N2  - Potash seams are a valuable resource containing several economically interesting, but also highly soluble minerals. In the presence of water, uncontrolled leaching can occur, endangering subsurface mining operations. In the present study, the influence of insoluble inclusions and intersecting layers on leaching zone evolution was examined by means of a reactive transport model. For that purpose, a scenario analysis was carried out, considering different rock distributions within a carnallite-bearing potash seam. The results show that reaction-dominated systems are not affected by heterogeneities at all, whereas transport-dominated systems exhibit a faster advance in homogeneous rock compositions. In return, the ratio of permeated rock in vertical direction is higher in heterogeneous systems. Literature data indicate that most natural potash systems are transport-dominated. Accordingly, insoluble inclusions and intersecting layers can usually be seen as beneficial with regard to reducing hazard potential as long as the mechanical stability of leaching zones is maintained. Thereby, the distribution of insoluble areas is of minor impact unless an inclined, intersecting layer occurs that accelerates leaching zone growth in one direction. Moreover, it is found that the saturation dependency of dissolution rates increases the growth rate in the long term, and therefore must be considered in risk assessments.
KW  - salt dissolution
KW  - reactive transport
KW  - heterogeneity
KW  - density-driven
KW  - convection
KW  - PHREEQC
KW  - porous media
Y1  - 2021
U6  - https://doi.org/10.3390/app11199314
SN  - 2076-3417
VL  - 11
IS  - 19
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Mantiloni, Lorenzo
A1  - Davis, Timothy
A1  - Gaete Rojas, Ayleen Barbara
A1  - Rivalta, Eleonora
T1  - Stress inversion in a gelatin box
BT  - testing eruptive vent location forecasts with analog models
JF  - Geophysical research letters : GRL / American Geophysical Union
N2  - Assessing volcanic hazard in regions of distributed volcanism is challenging because of the uncertain location of future vents. A statistical-mechanical strategy to forecast such locations was recently proposed: here, we further develop and test it with analog models. We stress a gelatin block laterally and with surface excavations, and observe air-filled crack trajectories. We use the observed surface arrivals to sample the distributions of parameters describing the stress state of the gelatin block, combining deterministic crack trajectory simulations with a Monte Carlo approach. While the individual stress parameters remain unconstrained, we effectively retrieve their ratio and successfully forecast the arrival points of subsequent cracks.
KW  - analog experiment
KW  - calderas
KW  - continental rifts
KW  - dike propagation
KW  - dike
KW  - trajectories
KW  - stress field
Y1  - 2021
U6  - https://doi.org/10.1029/2020GL090407
SN  - 0094-8276
SN  - 1944-8007
VL  - 48
IS  - 6
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Hofmann, Hannes
A1  - Blöcher, Guido
A1  - Zang, Arno
T1  - Special issue on rock fracturing and fault activation
BT  - experiments and models selected papers presented at the 13th EURO-Conference on rock physics and geomechanics - the Gueguen Conference Held on 2-6 September 2019 in Potsdam, Germany
JF  - Rock mechanics and rock engineering
Y1  - 2021
U6  - https://doi.org/10.1007/s00603-021-02635-4
SN  - 0723-2632
SN  - 1434-453X
VL  - 54
IS  - 10
SP  - 5149
EP  - 5153
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Hennig, Theresa
A1  - Kühn, Michael
T1  - Potential uranium migration within the geochemical gradient of the opalinus clay system at the Mont Terri
JF  - Minerals
N2  - Transport properties of potential host rocks for nuclear waste disposal are typically determined in laboratory or in-situ experiments under geochemically controlled and constant conditions. Such a homogeneous assumption is no longer applicable on the host rock scale as can be seen from the pore water profiles of the potential host rock Opalinus Clay at Mont Terri (Switzerland). The embedding aquifers are the hydro-geological boundaries, that established gradients in the 210 m thick low permeable section through diffusive exchange over millions of years. Present-day pore water profiles were confirmed by a data-driven as well as by a conceptual scenario. Based on the modelled profiles, the influence of the geochemical gradient on uranium migration was quantified by comparing the distances after one million years with results of common homogeneous models. Considering the heterogeneous system, uranium migrated up to 24 m farther through the formation depending on the source term position within the gradient and on the partial pressure of carbon dioxide pCO2 of the system. Migration lengths were almost equal for single- and multicomponent diffusion. Differences can predominantly be attributed to changes in the sorption capacity, whereby pCO2 governs how strong uranium migration is affected by the geochemical gradient. Thus, the governing parameters for uranium migration in the Opalinus Clay can be ordered in descending priority: pCO2, geochemical gradients, mineralogical heterogeneity.</p>
KW  - PHREEQC
KW  - reactive transport
KW  - sorption
KW  - diffusion
KW  - repository far-field
KW  - hydro-geological system
Y1  - 2021
U6  - https://doi.org/10.3390/min11101087
SN  - 2075-163X
VL  - 11
IS  - 10
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Körting, Friederike Magdalena
A1  - Köllner, Nicole
A1  - Kuras, Agnieszka
A1  - Bösche, Nina Kristin
A1  - Rogass, Christian
A1  - Mielke, Christian
A1  - Elger, Kirsten
A1  - Altenberger, Uwe
T1  - A solar optical hyperspectral library of rare-earth-bearing minerals, rare-earth oxide powders, copper-bearing minerals and Apliki mine surface samples
JF  - Earth system science data : ESSD
N2  - Mineral resource exploration and mining is an essential part of today's high-tech industry. Elements such as rare-earth elements (REEs) and copper are, therefore, in high demand. Modern exploration techniques from multiple platforms (e.g., spaceborne and airborne), to detect and map the spectral characteristics of the materials of interest, require spectral libraries as an essential reference. They include field and laboratory spectral information in combination with geochemical analyses for validation. Here, we present a collection of REE- and copper-related hyperspectral spectra with associated geochemical information. The libraries contain reflectance spectra from rare-earth element oxides, REE-bearing minerals, copper-bearing minerals and mine surface samples from the Apliki copper-gold-pyrite mine in the Republic of Cyprus. The samples were measured with the HySpex imaging spectrometers in the visible and near infrared (VNIR) and shortwave infrared (SWIR) range (400-2500 nm). The geochemical validation of each sample is provided with the reflectance spectra. The spectral libraries are openly available to assist future mineral mapping campaigns and laboratory spectroscopic analyses. The spectral libraries and corresponding geochemistry are published via GFZ Data Services with the following DOIs: https://doi.org/10.5880/GFZ.1.4.2019.004 (13 REE-bearing minerals and 16 oxide powders, Koerting et al., 2019a), https://doi.org/10.5880/GFZ.1.4.2019.003 (20 copper-bearing minerals, Koellner et al., 2019), and https://doi.org/10.5880/GFZ.1.4.2019.005 (37 copper-bearing surface material samples from the Apliki coppergold-pyrite mine in Cyprus, Koerting et al., 2019b). All spectral libraries are united and comparable by the internally consistent method of hyperspectral data acquisition in the laboratory.
Y1  - 2021
U6  - https://doi.org/10.5194/essd-13-923-2021
SN  - 1866-3508
SN  - 1866-3516
VL  - 13
SP  - 923
EP  - 942
PB  - Copernics Publications
CY  - Katlenburg-Lindau
ER  - 
TY  - JOUR
A1  - Izgi, Gizem
A1  - Eibl, Eva P. S.
A1  - Donner, Stefanie
A1  - Bernauer, Felix
T1  - Performance test of the rotational sensor blueSeis-3A in a huddle test in Fürstenfeldbruck
JF  - Sensors
N2  - Rotational motions play a key role in measuring seismic wavefield properties. Using newly developed portable rotational instruments, it is now possible to directly measure rotational motions in a broad frequency range. Here, we investigated the instrumental self-noise and data quality in a huddle test in Fürstenfeldbruck, Germany, in August 2019. We compare the data from six rotational and three translational sensors. We studied the recorded signals using correlation, coherence analysis, and probabilistic power spectral densities. We sorted the coherent noise into five groups with respect to the similarities in frequency content and shape of the signals. These coherent noises were most likely caused by electrical devices, the dehumidifier system in the building, humans, and natural sources such as wind. We calculated self-noise levels through probabilistic power spectral densities and by applying the Sleeman method, a three-sensor method. Our results from both methods indicate that self-noise levels are stable between 0.5 and 40 Hz. Furthermore, we recorded the 29 August 2019 ML 3.4 Dettingen earthquake. The calculated source directions are found to be realistic for all sensors in comparison to the real back azimuth. We conclude that the five tested blueSeis-3A rotational sensors, when compared with respect to coherent noise, self-noise, and source direction, provide reliable and consistent results. Hence, field experiments with single rotational sensors can be undertaken.
KW  - rotational seismology
KW  - huddle test
KW  - coherency
KW  - source direction
KW  - coherent noise
KW  - blueSeis-3A sensors
Y1  - 2021
U6  - https://doi.org/10.3390/s21093170
SN  - 1424-8220
VL  - 21
IS  - 9
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Han, Sungju
A1  - Kuhlicke, Christian
T1  - Barriers and drivers for mainstreaming nature-based solutions for flood risks
BT  - the case of South Korea
JF  - International journal of disaster risk science
N2  - Nature-based solutions (NBS) are seen as a promising adaptation measure that sustainably deals with diverse societal challenges, while simultaneously delivering multiple benefits. Nature-based solutions have been highlighted as a resilient and sustainable means of mitigating floods and other hazards globally. This study examined diverging conceptualizations of NBS, as well as the attitudinal (for example, emotions and beliefs) and contextual (for example, legal and political aspects) barriers and drivers of NBS for flood risks in South Korea. Semistructured interviews were conducted with 11 experts and focused on the topic of flood risk measures and NBS case studies. The analysis found 11 barriers and five drivers in the attitudinal domain, and 13 barriers and two drivers in the contextual domain. Most experts see direct monetary benefits as an important attitudinal factor for the public. Meanwhile, the cost-effectiveness of NBS and their capacity to cope with flood risks were deemed influential factors that could lead decision makers to opt for NBS. Among the contextual factors, insufficient systems to integrate NBS in practice and the ideologicalization of NBS policy were found to be peculiar barriers, which hinder consistent realization of initiatives and a long-term national plan for NBS. Understanding the barriers and drivers related to the mainstreaming of NBS is critical if we are to make the most of such solutions for society and nature. It is also essential that we have a shared definition, expectation, and vision of NBS.
KW  - climate change
KW  - flood risk management
KW  - nature-based solutions (NBS)
KW  - South Korea
Y1  - 2021
U6  - https://doi.org/10.1007/s13753-021-00372-4
SN  - 2095-0055
SN  - 2192-6395
VL  - 12
IS  - 5
SP  - 661
EP  - 672
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Purinton, Benjamin
A1  - Bookhagen, Bodo
T1  - Tracking downstream variability in large grain-size distributions in the South-Central Andes
JF  - Journal of geophysical research : F, Earth surface
N2  - Mixed sand- and gravel-bed rivers record erosion, transport, and fining signals in their bedload size distributions. Thus, grain-size data are imperative for studying these processes. However, collecting hundreds to thousands of pebble measurements in steep and dynamic high-mountain river settings remains challenging. Using the recently published digital grain-sizing algorithm PebbleCounts, we were able to survey seven large (>= 1,000 m2) channel cross-sections and measure thousands to tens-of-thousands of grains per survey along a 100-km stretch of the trunk stream of the Toro Basin in Northwest Argentina. The study region traverses a steep topographic and environmental gradient on the eastern margin of the Central Andean Plateau. Careful counting and validation allows us to identify measurement errors and constrain percentile uncertainties using large sample sizes. In the coarse >= 2.5 cm fraction of bedload, only the uppermost size percentiles (>= 95th) vary significantly downstream, whereas the 50th and 84th percentiles show less variability. We note a relation between increases in these upper percentiles and along-channel junctions with large, steep tributaries. This signal is strongly influenced by lithology and geologic structures, and mixed with local hillslope input. In steep catchments like the Toro Basin, we suggest nonlinear relationships between geomorphic metrics and grain size, whereby the steepest parts of the landscape exert primary control on the upper grain-size percentiles. Thus, average or median metrics that do not apply weights or thresholds to steeper topography may be less predictive of grain-size distributions in such settings.
KW  - digital grain sizing
KW  - downstream fining
KW  - fluvial geomorphology
KW  - grain-size distribution
KW  - pebblecounts
Y1  - 2021
U6  - https://doi.org/10.1029/2021JF006260
SN  - 2169-9003
SN  - 2169-9011
VL  - 126
IS  - 8
SP  - 1
EP  - 29
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Smith, Taylor
A1  - Rheinwalt, Aljoscha
A1  - Bookhagen, Bodo
T1  - Topography and climate in the upper Indus Basin
BT  - Mapping elevation-snow cover relationships
JF  - The science of the total environment : an international journal for scientific research into the environment and its relationship with man
N2  - The Upper Indus Basin (UIB), which covers a wide range of climatic and topographic settings, provides an ideal venue to explore the relationship between climate and topography. While the distribution of snow and glaciers is spatially and temporally heterogeneous, there exist regions with similar elevation-snow relationships. In this work, we construct elevation-binned snow-cover statistics to analyze 3415 watersheds and 7357 glaciers in the UIB region. We group both glaciers and watersheds using a hierarchical clustering approach and find that (1) watershed clusters mirror large-scale moisture transport patterns and (2) are highly dependent on median watershed elevation. (3) Glacier clusters are spatially heterogeneous and are less strongly controlled by elevation, but rather by local topographic parameters that modify solar insolation. Our clustering approach allows us to clearly define self-similar snow-topographic regions. Eastern watersheds in the UIB show a steep snow cover-elevation relationship whereas watersheds in the central and western UIB have moderately sloped relationships, but cluster in distinct groups. We highlight this snow-cover-topographic transition zone and argue that these watersheds have different hydrologic responses than other regions. Our hierarchical clustering approach provides a potential new framework to use in defining climatic zones in the cyrosphere based on empirical data.
KW  - Snow-cover
KW  - Hierarchical clustering
KW  - Glaciers
KW  - Upper Indus Basin
Y1  - 2021
U6  - https://doi.org/10.1016/j.scitotenv.2021.147363
SN  - 0048-9697
SN  - 1879-1026
VL  - 786
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Smith, Taylor
A1  - Bookhagen, Bodo
T1  - Climatic and biotic controls on topographic asymmetry at the global scale
JF  - Journal of geophysical research : JGR, Earth surface
N2  - Insolation differences play a primary role in controlling microclimate and vegetation cover, which together influence the development of topography. Topographic asymmetry (TA), or slope differences between terrain aspects, has been well documented in small-scale, field-based, and modeling studies. Here we combine a suite of environmental (e.g., vegetation, temperature, solar insolation) and topographic (e.g., elevation, drainage network) data to explore the driving mechanisms and markers of TA on a global scale. Using a novel empirical TA analysis method, we find that (1) steeper terrain has higher TA magnitudes, (2) globally, pole-facing terrain is on average steeper than equator-facing terrain, especially in mid-latitude, tectonically quiescent, and vegetated landscapes, and (3) high-elevation and low-temperature regions tend to have terrain steepened toward the equator. We further show that there are distinct differences in climate and vegetation cover across terrain aspects, and that TA is reflected in the size and form of fluvial drainage networks. Our work supports the argument that insolation asymmetries engender differences in local microclimates and vegetation on opposing terrain aspects, which broadly encourage the development of asymmetric topography across a range of lithologic, tectonic, geomorphic, and climatic settings.
KW  - erosion
KW  - freeze-thaw cycling
KW  - solar radiation
KW  - topographic asymmetry
KW  - topography
KW  - vegetation cover
Y1  - 2021
U6  - https://doi.org/10.1029/2020JF005692
SN  - 2169-9003
SN  - 2169-9011
VL  - 126
IS  - 1
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Purinton, Benjamin
A1  - Bookhagen, Bodo
T1  - Beyond Vertical Point Accuracy
BT  - Assessing Inter-pixel Consistency in 30 m Global DEMs for the Arid Central Andes
JF  - Frontiers in Earth Science
N2  - Quantitative geomorphic research depends on accurate topographic data often collected via remote sensing. Lidar, and photogrammetric methods like structure-from-motion, provide the highest quality data for generating digital elevation models (DEMs). Unfortunately, these data are restricted to relatively small areas, and may be expensive or time-consuming to collect. Global and near-global DEMs with 1 arcsec (∼30 m) ground sampling from spaceborne radar and optical sensors offer an alternative gridded, continuous surface at the cost of resolution and accuracy. Accuracy is typically defined with respect to external datasets, often, but not always, in the form of point or profile measurements from sources like differential Global Navigation Satellite System (GNSS), spaceborne lidar (e.g., ICESat), and other geodetic measurements. Vertical point or profile accuracy metrics can miss the pixel-to-pixel variability (sometimes called DEM noise) that is unrelated to true topographic signal, but rather sensor-, orbital-, and/or processing-related artifacts. This is most concerning in selecting a DEM for geomorphic analysis, as this variability can affect derivatives of elevation (e.g., slope and curvature) and impact flow routing. We use (near) global DEMs at 1 arcsec resolution (SRTM, ASTER, ALOS, TanDEM-X, and the recently released Copernicus) and develop new internal accuracy metrics to assess inter-pixel variability without reference data. Our study area is in the arid, steep Central Andes, and is nearly vegetation-free, creating ideal conditions for remote sensing of the bare-earth surface. We use a novel hillshade-filtering approach to detrend long-wavelength topographic signals and accentuate short-wavelength variability. Fourier transformations of the spatial signal to the frequency domain allows us to quantify: 1) artifacts in the un-projected 1 arcsec DEMs at wavelengths greater than the Nyquist (twice the nominal resolution, so > 2 arcsec); and 2) the relative variance of adjacent pixels in DEMs resampled to 30-m resolution (UTM projected). We translate results into their impact on hillslope and channel slope calculations, and we highlight the quality of the five DEMs. We find that the Copernicus DEM, which is based on a carefully edited commercial version of the TanDEM-X, provides the highest quality landscape representation, and should become the preferred DEM for topographic analysis in areas without sufficient coverage of higher-quality local DEMs.
KW  - DEM noise
KW  - Fourier analysis
KW  - TanDEM-X
KW  - ASTER GDEM
KW  - Copernicus DEM
KW  - WorldDEM
KW  - SRTM
KW  - ALOS World 3D
Y1  - 2021
U6  - https://doi.org/10.3389/feart.2021.758606
SN  - 2296-6463
SP  - 1
EP  - 24
PB  - Frontiers Media
CY  - Lausanne, Schweiz
ER  - 
TY  - JOUR
A1  - Runge, Alexandra
A1  - Nitze, Ingmar
A1  - Grosse, Guido
T1  - Remote sensing annual dynamics of rapid permafrost thaw disturbances with LandTrendr
JF  - Remote sensing of environment : an interdisciplinary journal
N2  - Permafrost is warming globally which leads to widespread permafrost thaw. Particularly ice-rich permafrost is vulnerable to rapid thaw and erosion, impacting whole landscapes and ecosystems. Retrogressive thaw slumps (RTS) are abrupt permafrost disturbances that expand by several meters each year and lead to an increased soil organic carbon release. Local Remote Sensing studies identified increasing RTS activity in the last two decades by increasing number of RTS or heightened RTS growth rates. However, a large-scale assessment across diverse permafrost regions and at high temporal resolution allowing to further determine RTS thaw dynamics and its main drivers is still lacking. In this study we apply the disturbance detection algorithm LandTrendr for automated large-scale RTS mapping and high temporal thaw dynamic assessment to North Siberia (8.1 x 106km2). We adapted and parametrised the temporal segmentation algorithm for abrupt disturbance detection to incorporate Landsat+Sentinel-2 mosaics, conducted spectral filtering, spatial masking and filtering, and a binary machine-learning object classification of the disturbance output to separate between RTS and false positives (F1 score: 0.609). Ground truth data for calibration and validation of the workflow was collected from 9 known RTS cluster sites using very highresolution RapidEye and PlanetScope imagery. Our study presents the first automated detection and assessment of RTS and their temporal dynamics at largescale for 2001-2019. We identified 50,895 RTS and a steady increase in RTS-affected area from 2001 to 2019 across North Siberia, with a more abrupt increase from 2016 onward. Overall the RTS-affected area increased by 331% compared to 2000 (2000: 20,158 ha, 2001-2019: 66,699 ha). Contrary to this, 5 focus sites show spatiotemporal variability in their annual RTS dynamics, with alternating periods of increased and decreased RTS development, indicating a close relationship to thaw drivers. The majority of identified RTS was active from 2000 onward and only a small proportion initiated during the assessment period, indicating that the increase in RTS-affected area was mainly caused by enlarging existing RTS and not by new RTS. The detected increase in RTS dynamics suggests advancing permafrost thaw and underlines the importance of assessing abrupt permafrost disturbances with high spatial and temporal resolution at large-scales. Obtaining such consistent disturbance products will help to parametrise regional and global climate change models.
KW  - retrogressive thaw slumps
KW  - time series
KW  - multi-spectral analysis
KW  - landsat
KW  - sentinel-2
KW  - thermo-erosion
KW  - permafrost thaw
Y1  - 2021
U6  - https://doi.org/10.1016/j.rse.2021.112752
SN  - 0034-4257
SN  - 1879-0704
VL  - 268
PB  - Elsevier
CY  - New York
ER  - 
TY  - JOUR
A1  - Steding, Svenja
A1  - Schneider, Wilfried
T1  - Prognose des Schadstoffaustrags aus mehrphasigen DNAPL-Pools mittels semi-analytischem Berechnungsmodell
JF  - Grundwasser : Zeitschrift der Fachsektion Hydrogeologie in der Deutschen Gesellschaft für Geowissenschaften (FH-DGG)
N2  - Multicomponent DNAPL pools are among the most common reasons for groundwater contamination and represent highly persistent source areas. Although several studies have already shown that their constituents influence each other's solubility, existing models neglect these interactions. For this reason, a semi-analytical model has been developed, considering the pool composition as temporally variable. Based on Raoult's law, the molar fraction, the effective solubility and finally the mass discharge due to advection, dispersion and diffusion of each component are determined. The results significantly differ from studies on single-phase pools. It is shown that mass discharges can both increase and decrease over time and that the longevity of DNAPL pools as well as the time until threshold values are fullfilled will be significantly underestimated if Raoult's law is neglected. Additionally, a sensitivity analysis reveals that poorly soluble minor components must not be neglected, whereas highly soluble ones can.
N2  - Mehrphasige DNAPL-Pools zählen zu den häufigsten Ursachen für Grundwasserkontaminationen und sind bekannt für ihre Langlebigkeit. Obwohl Untersuchungen bereits gezeigt haben, dass die Phasen sich in ihrer Wasserlöslichkeit gegenseitig beeinflussen, werden diese Interaktionen von bisherigen Modellen vernachlässigt. Aus diesem Grund wurde ein semi-analytisches Berechnungsmodell entwickelt, welches die Poolzusammensetzung als zeitlich variabel behandelt. Basierend auf dem Raoult’schen Gesetz werden für jede Komponente Molanteil, effektive Wasserlöslichkeit und schließlich der Schadstoffaustrag infolge Advektion, Dispersion und Diffusion bestimmt. Die Ergebnisse unterscheiden sich deutlich von Studien an einphasigen Pools. So wird gezeigt, dass Schadstofffrachten über die Zeit sowohl zu- als auch abnehmen können und dass ohne Berücksichtigung des Raoult’schen Gesetzes sowohl die Langlebigkeit von DNAPL-Pools als auch die Dauer bis zur Unterschreitung von Grenzwerten teils deutlich unterschätzt wird. Eine Sensitivitätsanalyse zeigt zudem, dass schwer lösliche Nebenbestandteile nicht vernachlässigt werden dürfen, leicht lösliche hingegen schon.
T2  - Prediction of mass discharge from multicomponent DNAPL pools using a semi-analytical model
KW  - Contamination
KW  - Source longevity
KW  - Raoult's law
KW  - Matrix diffusion
KW  - Minor
KW  - components
Y1  - 2021
U6  - https://doi.org/10.1007/s00767-021-00490-2
SN  - 1430-483X
SN  - 1432-1165
VL  - 26
IS  - 3
SP  - 241
EP  - 253
PB  - Springer
CY  - Berlin ; Heidelberg
ER  - 
TY  - JOUR
A1  - Korges, Maximilian
A1  - Junge, Malte
A1  - Borg, Gregor
A1  - Oberthür, Thomas
T1  - Supergene mobilization and redistribution of platinum-group elements in the Merensky Reef, eastern Bushveld Complex, South Africa
JF  - The Canadian mineralogist
N2  - Near-surface supergene ores of the Merensky Reef in the Bushveld Complex, South Africa, contain economic grades of platinum-group elements, however, these are currently uneconomic due to low recovery rates. This is the first study that investigates the variation in platinum-group elements in pristine and supergene samples of the Merensky Reef from five drill cores from the eastern Bushveld. The samples from the Richmond and Twickenham farms show different degrees of weathering. The whole-rock platinum-group element distribution was studied by inductively coupled plasma-mass spectrometry and the platinum-group minerals were investigated by reflected-light microscopy, scanning electron microscopy, and electron microprobe analysis. <br /> In pristine ("fresh") Merensky Reef samples, platinum-group elements occur mainly as discrete platinum-group minerals, such as platinum-group element-sulfides (cooperite-braggite) and laurite as well as subordinate platinum-group elementbismuthotellurides and platinum-group element-arsenides, and also in solid solution in sulfides (especially Pd in pentlandite). During weathering, Pd and S were removed, resulting in a platinum-group mineral mineralogy in the supergene Merensky Reef that mainly consists of relict platinum-group minerals, Pt-Fe alloys, and Pt-oxides/hydroxides. Additional proportions of platinum-group elements are hosted by Fe-hydroxides and secondary hydrosilicates (e.g., serpentine group minerals and chlorite). <br /> In supergene ores, only low recovery rates (ca. 40%) are achieved due to the polymodal and complex platinum-group element distribution. To achieve higher recovery rates for the platinum-group elements, hydrometallurgical or pyrometallurgical processing of the bulk ore would be required, which is not economically viable with existing technology.
KW  - Bushveld Complex
KW  - Merensky Reef
KW  - PGE
KW  - PGM
KW  - supergene ores
KW  - weathering
Y1  - 2021
U6  - https://doi.org/10.3749/canmin.2100023
SN  - 1499-1276
VL  - 59
IS  - 6
SP  - 1381
EP  - 1396
PB  - Mineralogical Association of Canada
CY  - Ottawa
ER  - 
TY  - JOUR
A1  - Steding, Svenja
A1  - Kempka, Thomas
A1  - Zirkler, Axel
A1  - Kühn, Michael
T1  - Spatial and temporal evolution of leaching zones within potash seams reproduced by reactive transport simulations
JF  - Water / Molecular Diversity Preservation International (MDPI)
N2  - Leaching zones within potash seams generally represent a significant risk to subsurface mining operations and the construction of technical caverns in salt rocks, but their temporal and spatial formation has been investigated only rudimentarily to date. To the knowledge of the authors, current reactive transport simulation implementations are not capable to address hydraulic-chemical interactions within potash salt. For this reason, a reactive transport model has been developed and complemented by an innovative approach to calculate the interchange of minerals and solution at the water-rock interface. Using this model, a scenario analysis was carried out based on a carnallite-bearing potash seam. The results show that the evolution of leaching zones depends on the mineral composition and dissolution rate of the original salt rock, and that the formation can be classified by the dimensionless parameters of Peclet (Pe) and Damkohler (Da). For Pe > 2 and Da > 1, a funnel-shaped leaching zone is formed, otherwise the dissolution front is planar. Additionally, Da > 1 results in the formation of a sylvinitic zone and a flow barrier. Most scenarios represent hybrid forms of these cases. The simulated shapes and mineralogies are confirmed by literature data and can be used to assess the hazard potential.
KW  - carnallite
KW  - water rock interaction
KW  - density-driven flow
KW  - PHREEQC
KW  - Pitzer
KW  - equations
Y1  - 2021
U6  - https://doi.org/10.3390/w13020168
SN  - 2073-4441
VL  - 13
IS  - 2
PB  - Molecular Diversity Preservation International
CY  - Basel
ER  - 
TY  - JOUR
A1  - Ramezani Ziarani, Maryam
A1  - Bookhagen, Bodo
A1  - Schmidt, Torsten
A1  - Wickert, Jens
A1  - de la Torre, Alejandro
A1  - Deng, Zhiguo
A1  - Calori, Andrea
T1  - A model for the relationship between rainfall, GNSS-derived integrated water vapour, and CAPE in the eastern central Andes
JF  - Remote Sensing
N2  - Atmospheric water vapour content is a key variable that controls the development of deep convective storms and rainfall extremes over the central Andes. Direct measurements of water vapour are challenging; however, recent developments in microwave processing allow the use of phase delays from L-band radar to measure the water vapour content throughout the atmosphere: Global Navigation Satellite System (GNSS)-based integrated water vapour (IWV) monitoring shows promising results to measure vertically integrated water vapour at high temporal resolutions. Previous works also identified convective available potential energy (CAPE) as a key climatic variable for the formation of deep convective storms and rainfall in the central Andes. Our analysis relies on GNSS data from the Argentine Continuous Satellite Monitoring Network, Red Argentina de Monitoreo Satelital Continuo (RAMSAC) network from 1999 to 2013. CAPE is derived from version 2.0 of the ECMWF’s (European Centre for Medium-Range Weather Forecasts) Re-Analysis (ERA-interim) and rainfall from the TRMM (Tropical Rainfall Measuring Mission) product. In this study, we first analyse the rainfall characteristics of two GNSS-IWV stations by comparing their complementary cumulative distribution function (CCDF). Second, we separately derive the relation between rainfall vs. CAPE and GNSS-IWV. Based on our distribution fitting analysis, we observe an exponential relation of rainfall to GNSS-IWV. In contrast, we report a power-law relationship between the daily mean value of rainfall and CAPE at the GNSS-IWV station locations in the eastern central Andes that is close to the theoretical relationship based on parcel theory. Third, we generate a joint regression model through a multivariable regression analysis using CAPE and GNSS-IWV to explain the contribution of both variables in the presence of each other to extreme rainfall during the austral summer season. We found that rainfall can be characterised with a higher statistical significance for higher rainfall quantiles, e.g., the 0.9 quantile based on goodness-of-fit criterion for quantile regression. We observed different contributions of CAPE and GNSS-IWV to rainfall for each station for the 0.9 quantile. Fourth, we identify the temporal relation between extreme rainfall (the 90th, 95th, and 99th percentiles) and both GNSS-IWV and CAPE at 6 h time steps. We observed an increase before the rainfall event and at the time of peak rainfall—both for GNSS-integrated water vapour and CAPE. We show higher values of CAPE and GNSS-IWV for higher rainfall percentiles (99th and 95th percentiles) compared to the 90th percentile at a 6-h temporal scale. Based on our correlation analyses and the dynamics of the time series, we show that both GNSS-IWV and CAPE had comparable magnitudes, and we argue to consider both climatic variables when investigating their effect on rainfall extremes.
KW  - Global Navigation Satellite System (GNSS)
KW  - GNSS-integrated water vapour
KW  - convective available potential energy (CAPE)
KW  - extreme rainfall
KW  - TRMM
Y1  - 2021
U6  - https://doi.org/10.3390/rs13183788
SN  - 2072-4292
VL  - 13
IS  - 18
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Soergel, Bjoern
A1  - Kriegler, Elmar
A1  - Weindl, Isabelle
A1  - Rauner, Sebastian
A1  - Dirnaichner, Alois
A1  - Ruhe, Constantin
A1  - Hofmann, Matthias
A1  - Bauer, Nico
A1  - Bertram, Christoph
A1  - Bodirsky, Benjamin Leon
A1  - Leimbach, Marian
A1  - Leininger, Julia
A1  - Levesque, Antoine
A1  - Luderer, Gunnar
A1  - Pehl, Michaja
A1  - Wingens, Christopher
A1  - Baumstark, Lavinia
A1  - Beier, Felicitas
A1  - Dietrich, Jan Philipp
A1  - Humpenöder, Florian
A1  - von Jeetze, Patrick
A1  - Klein, David
A1  - Koch, Johannes
A1  - Pietzcker, Robert C.
A1  - Strefler, Jessica
A1  - Lotze-Campen, Hermann
A1  - Popp, Alexander
T1  - A sustainable development pathway for climate action within the UN 2030 Agenda
JF  - Nature climate change
N2  - Ambitious climate policies, as well as economic development, education, technological progress and less resource-intensive lifestyles, are crucial elements for progress towards the UN Sustainable Development Goals (SDGs). However, using an integrated modelling framework covering 56 indicators or proxies across all 17 SDGs, we show that they are insufficient to reach the targets. An additional sustainable development package, including international climate finance, progressive redistribution of carbon pricing revenues, sufficient and healthy nutrition and improved access to modern energy, enables a more comprehensive sustainable development pathway. We quantify climate and SDG outcomes, showing that these interventions substantially boost progress towards many aspects of the UN Agenda 2030 and simultaneously facilitate reaching ambitious climate targets. Nonetheless, several important gaps remain; for example, with respect to the eradication of extreme poverty (180 million people remaining in 2030). These gaps can be closed by 2050 for many SDGs while also respecting the 1.5 °C target and several other planetary boundaries.
KW  - climate-change mitigation
KW  - climate-change policy
KW  - socioeconomic scenarios
KW  - sustainability
Y1  - 2021
U6  - https://doi.org/10.1038/s41558-021-01098-3
SN  - 1758-678X
SN  - 1758-6798
VL  - 11
IS  - 8
SP  - 656
EP  - 664
PB  - Nature Publishing Group
CY  - London
ER  - 
TY  - JOUR
A1  - Samprogna Mohor, Guilherme
A1  - Thieken, Annegret
A1  - Korup, Oliver
T1  - Residential flood loss estimated from Bayesian multilevel models
JF  - Natural Hazards and Earth System Sciences
N2  - Models for the predictions of monetary losses from floods mainly blend data deemed to represent a single flood type and region. Moreover, these approaches largely ignore indicators of preparedness and how predictors may vary between regions and events, challenging the transferability of flood loss models. We use a flood loss database of 1812 German flood-affected households to explore how Bayesian multilevel models can estimate normalised flood damage stratified by event, region, or flood process type. Multilevel models acknowledge natural groups in the data and allow each group to learn from others. We obtain posterior estimates that differ between flood types, with credibly varying influences of water depth, contamination, duration, implementation of property-level precautionary measures, insurance, and previous flood experience; these influences overlap across most events or regions, however. We infer that the underlying damaging processes of distinct flood types deserve further attention. Each reported flood loss and affected region involved mixed flood types, likely explaining the uncertainty in the coefficients. Our results emphasise the need to consider flood types as an important step towards applying flood loss models elsewhere. We argue that failing to do so may unduly generalise the model and systematically bias loss estimations from empirical data.
KW  - damage
KW  - insurance
KW  - Germany
KW  - transferability
KW  - preparedness
KW  - recovery
Y1  - 2020
U6  - https://doi.org/10.5194/nhess-21-1599-2021
SN  - 2195-9269
VL  - 21
SP  - 1599
EP  - 1614
PB  - European Geophysical Society
CY  - Katlenburg-Lindau
ER  - 
TY  - JOUR
A1  - Kaiser, Soraya
A1  - Grosse, Guido
A1  - Boike, Julia
A1  - Langer, Moritz
T1  - Monitoring the transformation of Arctic landscapes
BT  - automated shoreline change detection of lakes using very high resolution imagery
JF  - Remote sensing / Molecular Diversity Preservation International (MDPI)
N2  - Water bodies are a highly abundant feature of Arctic permafrost ecosystems and strongly influence their hydrology, ecology and biogeochemical cycling. While very high resolution satellite images enable detailed mapping of these water bodies, the increasing availability and abundance of this imagery calls for fast, reliable and automatized monitoring. This technical work presents a largely automated and scalable workflow that removes image noise, detects water bodies, removes potential misclassifications from infrastructural features, derives lake shoreline geometries and retrieves their movement rate and direction on the basis of ortho-ready very high resolution satellite imagery from Arctic permafrost lowlands. We applied this workflow to typical Arctic lake areas on the Alaska North Slope and achieved a successful and fast detection of water bodies. We derived representative values for shoreline movement rates ranging from 0.40-0.56 m yr(-1) for lake sizes of 0.10 ha-23.04 ha. The approach also gives an insight into seasonal water level changes. Based on an extensive quantification of error sources, we discuss how the results of the automated workflow can be further enhanced by incorporating additional information on weather conditions and image metadata and by improving the input database. The workflow is suitable for the seasonal to annual monitoring of lake changes on a sub-meter scale in the study areas in northern Alaska and can readily be scaled for application across larger regions within certain accuracy limitations.
KW  - change detection
KW  - shoreline movement rate
KW  - shoreline movement direction
KW  - arctic water bodies
KW  - permafrost lowlands
KW  - automated monitoring
KW  - North
KW  - Slope
KW  - very high resolution imagery
Y1  - 2021
U6  - https://doi.org/10.3390/rs13142802
SN  - 2072-4292
VL  - 13
IS  - 14
PB  - MDPI
CY  - Basel
ER  -