bluuebunny/crossref_metadata_2025 huggingface dataset:
A deformed wedge-top basin inverted during the collapse of the Variscan belt: the Permo-Carboniferous Lorraine Basin (NE France)
Authors: Hemelsdaël Romain , Averbuch Olivier , Beccaletto Laurent , Izart Alain , Capar Laure , Marc Stéphane , Michels Raymond
Published: February 2023

A new structural model is presented for the Permo-Carboniferous Lorraine Basin (NE France), a major intramountain basin that developed during the latest stages of the Variscan orogeny (ca 315–270 Ma). This basin is buried in NE France below the Paris Basin but outcrops in southern Germany (Saar-Nahe Basin). Digitalized well logs and reprocessed seismic data were used to decipher the kinematic evolution of this basin located along the Rhenohercynian orogenic suture zone. The basin initiated during the late collision stage (Late Namurian-Westphalian) in a wedge- top position upon the Saxothüringian retrowedge. The syn-orogenic sequences are delimited to the north by the major SE-directed Metz Thrust, which is part of the backthrust system that propagated during Late Westphalian times. Seismic data provide evidence of negative tectonic inversion, allowing the formation of syn-rift depocenters (Stephanian-Early Permian) above the former anticlines. Erosion of these anticlines results in a major unconformity (base of Stephanian) marking the onset of post-orogenic collapse stage. The late Early Permian shortening (Saalian phase) reactivated former thrusts and normal faults, thus generating uplift of the basin. The post- orogenic phase is complex and diachronous at basin scale, and both compression and extension can be recorded in the same area over a short period (<10 Ma). The Late Carboniferous negative tectonic inversion along the Rhenohercynian suture zone is proposed to result from the lithospheric delamination of the Variscan orogenic roots. The associated upwelling of asthenospheric material is recorded by intense magmatic activity, and can be, in turn, considered as the main trigger for the subsequent thermal subsidence of the Paris basin.
Vertical transport of microplastic in agricultural soil in controlled irrigation plot experiments
Authors: Li Wang , Ray Saunak Sinha , Severe Emilee , Zumr David , Dostál Tomáš , Krasa Josef , Wilken Florian , Quinton John N. , Maqbool Ahsan , G ́omez Jos ́e Alfonso , Stumpp Christine
Published: February 2023

Microplastic pollution in agricultural sites has gained increased attention in recent years. Many studies focused on the impact of plastic residues on soil functions, such as soil physiochemical properties, fertility, and biodiversity. However, research on the transport behavior of microplastics (MPs) in agricultural soil remains rare. Therefore, it is important to understand the transport mechanism of MPs in the natural environment. Plot experiments (1x1 m) were conducted in an agricultural site (silty loam) near Prague to investigate the size-dependent movement of MPs under both artificial irrigation (first campaign) and natural rainfall (second campaign). Before irrigation, fluorescent PE microspheres with four different size ranges (53-63 µm, 125-150 µm, 250-300 µm, 425-500 µm) were mixed with soil and then uniformly distributed on the plot surface (upper 1 cm). Deuterium as a conservative tracer was added and well mixed with water for the rainfall simulation. The rainfall simulation with an intensity of 60 mm/h was applied. Results from the first campaign show that the maximum migration depth of MPs was up to 4-6 cm, which is consistent with the results from the tracer experiment. Moreover, larger particles were mostly found on the top layer up to 2 cm, with small MPs at 53-63 µm transported down to 6 cm. These results indicate that the infiltration of water could enhance the movement of MPs in the soil profile, with smaller MPs having higher mobility under rainfall simulation. This finding provides insight into the mobility of MPs in agricultural soils, and it could be applied for control and risk assessment to estimate the potential of MPs leaching into aquifer systems.
Carbon and nitrogen exchange between trees and mycorrhizal fungi at treeline ecotone
Authors: Hilman Boaz , Solly Emily , Brunner Ivano , Trumbore Susan , Hagedorn Frank
Published: February 2023

The formation of high elevation treelines is thought to result from direct low-temperature growth limitation, but the in-direct role of nitrogen (N) in modifying growth has rarely been evaluated. Slow N mineralization rates in cold soils may push trees to rely more on N supplied by symbiotic mycorrhizal fungi. Here, we investigated the carbon (C) and N exchange between trees and mycorrhizal fungi along an Alpine treeline ecotone using bomb 14C and natural abundance isotopes (13C and 15N). We collected fine roots, branches, and needles from two tree species (Larix decidua L. and Pinus mugo spp. uncinata Ramond) and sporocarps of mycorrhizal and free-living (saprotrophic) fungal genera. 14C measurements demonstrated that mycorrhizal fungi rely on new photo-assimilates derived from fine roots, while saprotrophic fungi feed on several years old C (4-10 yr). The C transfer root-fungi seems to have isotopic fractionation that enriches the fungi with 13C in 1-5‰. Mycorrhizal fungi had higher δ15N values and C:N ratio than saprotrophic fungi. Assuming that the two fungi types share the same N source in the soil, the 15N enrichment and the lower N concentration of the mycorrhizal fungi could be explained through preferential transfer of 14N to the hosting trees. The δ15N in the trees generally decreased with increasing elevation, suggesting a greater reliance on N supplied by mycorrhizal fungi in colder soils. However, abrupt increase in the Larix δ15N at the treeline suggests opening of the N cycle for this deciduous tree species, either by a decreasing N demand of slow-growing trees or a reduced competition for N with other plants. Overall, our results indicate that in cold treeline ecotones the sources and availabilities of soil N have a key influence on determing the N uptake pathways of trees and consequently plant growth.
Smoke self-lofting towards the lower stratosphere: an alternative process to pyroCb-lofting
Authors: Ohneiser Kevin , Ansmann Albert , Witthuhn Jonas , Deneke Hartwig , Chudnovsky Alexandra , Walter Gregor , Senf Fabian
Published: February 2023

Wildfire smoke is known as a highly absorptive aerosol type in the shortwave wavelength range. The absorption of Sun light by optically thick smoke layers results in heating of the ambient air. This heating is translated into self-lofting of the smoke up to more than 1 km in altitude per day. The main goal is to demonstrate that radiative heating of intense smoke plumes is capable of lofting them from the lower and middle free troposphere (injection heights) up to the tropopause without the need of pyrocumulonimbus (pyroCb) convection. The further subsequent ascent within the lower stratosphere (caused by self-lofting) is already well documented in the literature. Simulations of heating rates which are then converted into lofting rates are conducted by using the ECRAD (European Centre for Medium-Range Weather Forecasts Radiation) scheme. As input parameters thermodynamic profiles from CAMS (Copernicus Atmosphere Monitoring Service) reanalysis data, aerosol profiles from ground-based lidar observations, radiosonde potential temperature profiles, CALIOP (Cloud Aerosol Lidar with Orthogonal Polarization) aerosol measurements, and MODIS (Moderate Resolution Imaging Spectroradiometer) aerosol optical depth retrievals were used. The sensitivity analysis revealed that the lofting rate strongly depends on aerosol optical thickness (AOT), layer thickness, layer height, and black carbon (BC) fraction. We also looked at the influence of different meteorological parameters such as cloudiness, relative humidity, and potential temperature gradient. Lofting processes in the stratosphere observed with CALIOP after major pyroCb events (Canadian fires, 2017, Australian fires 2019-2020) are compared with simulations to demonstrate the applicability of our self-lofting model. We analyzed long-term CALIOP observations of Siberian smoke layers and plumes evolving in the troposphere and UTLS (upper troposphere and lower stratosphere) region over Siberia and the adjacent Arctic during the summer season of 2019 and found several indications (fingerprints) that self-lofting contributed to the vertical transport of smoke. We hypothesize that the formation of a near-tropopause aerosol layer, observed with CALIOP over several months, was the result of self-lofting processes because this is in line with the self-lofting simulations. We will show a detailed analysis of tropospheric and stratospheric smoke lofting rates based on simulations and observations.
Non-contact methods for measuring craters formed on soil after a drop impact
Authors: Mazur Rafał , Beczek Michał , Ryżak Magdalena , Sochan Agata , Polakowski Cezary , Gibała Karolina , Bieganowski Andrzej
Published: February 2023

The splash phenomenon is one of the stages of water erosion, i.e. a process that causes soil degradation. The crux of splash is the detachment and displacement of soil particles due to the impact of raindrops. Another important aspect of the phenomenon is that a deformation called a crater is formed at the point of the impact. Research on craters helps to expand the knowledge of the splash phenomenon and may contribute to understanding its relationship with successive stages of water erosion. The quantities used to describe the deformation include static dimensions (e.g. depth or diameter of the crater) and dynamic quantities to describe the course of the deformation (e.g. the time for the crater to reach a stable shape). The small size of the craters and the high dynamics of their formation induce the use of accurate and advanced measurement methods.The aim of the work is to present selected non-contact methods for measuring craters formed on soil after a drop impact.The study was focused on photography, high-speed imaging, 3D surface modelling, and computed tomography (CT). The discussion of the methods includes a brief description of the measurements, the range of quantities that can be determined with the methods, and indication of their strengths and weaknesses. Knowledge of these issues allows making an informed choice of measurement methods when planning new experiments or projects, which may significantly affect the results that can be obtained. ReferencesMazur, R.; Ryżak, M.; Sochan, A.; Beczek, M.; Polakowski, C.; Bieganowski, A. Soil Deformation after Water Drop Impact—A Review of the Measurement Methods. Sensors 2023, 23, 121. https://doi.org/10.3390/s23010121This work was partially supported by the National Science Centre, Poland within the framework of project no. 2020/37/N/ST10/03363.
Galactic Cosmic Ray Cutoff Rigidities and Flux at Jupiter
Authors: Enghoff Martin Bødker , Svensmark Jacob , Jørgensen John Leif , Herceg Matija , Kotsiaros Stavros , Connerney John E. P.
Published: February 2023

Galactic cosmic rays (GCRs), primarily consisting of protons, are ubiquitous throughout the solar system. The greatest source is supernova activity and the flux in the solar system is modulated by the solar wind. Planets can be shielded if they possess a magnetic field. Jupiter’s magnetic field is the strongest in the solar system and has several interesting features such as the Great Blue Spot near the Equator. The JUNO satellite has mapped the magnetic field of Jupiter in great detail (Connerney et al, JGR Planets 127(2), 2022) resulting in the JRM33 model, composed of data from 32 polar orbits of JUNO around Jupiter.We have calculated a cosmic ray cutoff rigidity map for Jupiter. This was done using a modified version of a particle trajectory program (the Geomagnetic Cutoff Rigidity Computer Program by Smart and Shea (2001, Tech. Rep. No. 20010071975)) with the first 12 degrees and orders of the spherical harmonic expansion from the JRM33 model as input. This is done for vertical GCR entry into Jupiter’s atmosphere at a height of 67.5 km above the 1 bar level and for distances further out where high energy particles have been detected by JUNO. The energies required to enter into Jupiter’s atmosphere varies by several orders of magnitude from above 2500 GeV at locations around the Great Blue Spot and going downwards towards the poles.The modulation of the GCR proton flux into Jupiter’s atmosphere was then calculated. For the incoming GCR spectrum we used data from the BESS-POLAR II Antarctic mission (Abe et al, ApJ 822(2), 2016), collected at solar minimum where the modulation by the solar wind is at its lowest. By fitting the measured spectrum and using the calculated cutoff rigidities we have made a map of the proton flux into Jupiter’s atmosphere.Finally, we have investigated several incidents of high energy heavy ion detections by JUNO (Becker et al, JGR Planets 126, 2021) by calculating the cutoff rigidities from several incoming angles at the locations where JUNO made the detections and along the corresponding M-shells.
A 3D finite element magma reservoir simulator
Authors: Hu Haiyang , Salinas Pablo , Jackson Matthew
Published: February 2023

IC-FEMRES (Imperial College Finite Element Magma REservoir Simulator), is a finite-element based numerical code for simulating the 3D dynamic behaviour of a two-phase, multi-component magma reservoir with chemical reaction.  The code is built upon the open-source IC-FERST package (http://multifluids.github.io/) which includes advanced numerical features such as dynamic mesh optimization, to allow fine-scale solution features to be captured while simulating in a large domain.The model solves for velocity using a finite-element approach, and for transport using a control-volume scheme to ensure the conservation of energy, mass, and components.  Solid, melt and volatile phases are modelled as Stokes fluids with very different Newtonian viscosities.  Individual crystals in the solid matrix are incompressible, but the solid phase is compressible to account for changes in melt fraction.  The formulation captures viscous compaction and convection of the solid matrix, and flow of melt and volatiles via a Darcy-type formulation at low melt fraction, and a hindered-settling type approach at high melt fraction.  It also captures heat transport by conduction and advection, and component transport by advection.  A chemical model is used to calculate phase fraction and composition.  The numerical package sequentially solves for: 1. Melt and solid velocity (mass and momentum conservation); 2. Enthalpy and component transport (energy and component conservation); 3. Phase fraction and composition (chemical model).  Material properties such as density and viscosity can be coupled to solution fields such as melt fraction and composition to yield a highly non-linear system of coupled equations that are solved iteratively.We demonstrate here the validation of the formulation against well-constrained test cases, and example results for a magma reservoir in the continental crust obtained using a simple two-component chemical model created by fitting a binary phase diagram to experimental melting data.  Solutions show significant deviations from the predictions of 1- and 2D thermal models, or 1D models that include magma dynamics, and may explain some hitherto poorly understood aspects of magma reservoir formation, dynamics and chemical differentiation. 
Enhanced winter biogeochemical activity in Antarctic first-year sea ice
Authors: Audh Riesna R. , Fawcett Sarah E. , Johnson Siobhan , Rampai Tokoloho , Vichi Marcello
Published: February 2023

The study of Antarctic first-year ice as a biogeochemical habitat has been limited by samples mostly collected in pack ice during summer. Fewer winter data are available, and due to the harsh conditions, data from the marginal ice zone (MIZ) are even more difficult to obtain. The MIZ is broad and circumpolar in the Southern Ocean; it is found at different latitudes during the year with sufficient light and nutrients to sustain primary production and affect ecosystem functioning. We present the first dataset of biogeochemical properties of first-year ice collected in the Atlantic sector of the Southern Ocean during winter 2019, obtained from young pancake ice and consolidated first-year ice. Temperature, salinity, crystal structure, δ18O, chl-a and bulk macronutrient data were used to investigate the winter habitat and explain the transition from young ice to first year ice through exchanges with the ocean biogeochemistry. Data suggests that the sea ice sampled at the consolidated station was a result of thermodynamic processes combined with possibly multiple cycles of breaking and rafting induced by waves and dynamics, which ultimately enhanced the biogeochemical activity beyond what expected for first-year ice. A numerical model was used to support the hypothesis that winter first-year ice buffers biogeochemical components differently from the upper ocean winter concentrations, and this may determine the conditions for the biogeochemical development later in spring.
Volcanically driven short-term, regional-scale cooling during the early Paleogene Greenhouse?
Authors: Vickers Madeleine L. , Bernasconi Stefano M. , Peterse Francien , Sluijs Appy , Ullmann Clemens V. , Longman Jack , Stokke Ella Wulfsberg , Frieling Joost , Bajnai David , Clementi Vincent J. , Harper Dustin , Nelissen Mei , Brinkhuis Henk , Planke Sverre , Jones Morgan T. , Science Party IODP Expedition
Published: February 2023

Sediment cores from the Mid-Norwegian Margin, IODP Expedition 396 recovered several glendonite (calcite) pseudomorphs after cold-water ikaite, CaCO3•6H2O, within sediments deposited during the Paleocene-Eocene Thermal Maximum hyperthermal and the early Eocene greenhouse. This presents an apparent climate paradox, since during this time interval, deep sea bottom water temperatures are not believed to have been lower than c. 10 °C anywhere on Earth, mostly much warmer (Meckler et al., 2022 and references therein), far above temperatures typical for natural ikaite formation (Vickers et al., 2022 and references therein). The glendonites are found in close association with ash horizons from the nearby North Atlantic large igneous province (NAIP), with some actually in the infill of a hydrothermal. This, coupled with the presence of glendonites in sediments of the same age from Svalbard and Denmark (Spielhagen and Tripati, 2009; Vickers et al., 2020), may point to volcanically-driven climate and environmental changes in this region, perhaps on temporal and spatial scales hitherto unresolved by global-scale datasets. Here, we present reconstructed ikaite crystallisation temperatures from clumped isotope palaeothermometry and biomarker sea surface and air temperature reconstructions from glendonite-bearing horizons in ash-rich sediments at four IODP Expedition 396 sites. We find that the glendonites indicate bottom water temperatures considerably lower than the majority of other localities so far studied for this time interval (0 – 10 °C). The biomarker signals are harder to interpret, but may indicate sea surface and air temperatures significantly lower than many other studies across this time interval. We discuss possible causes and mechanisms for this cooling, and the conditions driving ikaite growth, focussing on whether these both may be linked to NAIP volcanism.
How realistic are multi-decadal reconstructions of GRACE-like total water storage anomalies?
Authors: Hacker Charlotte
Published: February 2023

The Gravity Recovery and Climate Experiment (GRACE) mission has monitored total water storage anomalies (TWSA) globally with unprecedented resolution and accuracy since 2002. However, many applications require a data-based, multi-decadal extended record of TWSA prior to the GRACE period as well as bridging the eleven-months gap between GRACE and its successor GRACE-FO. Statistical and machine-learning 'reconstruction' approaches have been developed to this end, mostly via identifying relations of GRACE-derived TWSA to climate variables, and some regional or global land data sets are now publicly available.In this contribution, we  compare the two global reconstructions by HUMPHREY AND GUDMUNDSSON (2019) and LI ET AL. (2021) mutually and against output from the the WaterGAP hydrological model from 1979 onwards, against large-scale mass-change derived from geodetic satellite laser ranging from 1992 onwards, and finally against differing GRACE/-FO solutions from 2002 onwards. We find that the reconstructions agree surprisingly well in many regions at seasonal and sub-seasonal timescales, even in the pre-GRACE era. We find larger differences at inter-annual timescales which we speculate are in part due to the way reconstructions are trained and in part on which specific GRACE solution they are trained as well as the climatological characteristic of the region. Our comparisons against independent SLR data reveal that reconstructions (only) partially succeed in representing anomalous TWSA for regions that are influenced by large climate modes such as ENSO.
Understanding the Potential Changes in Causal-Physical Drivers of Extreme Mei-yu Precipitation and Potential Applications
Authors: Ng Kelvin S. , Leckebusch Gregor C. , Hodges Kevin I.
Published: February 2023

Accurate predictions of extreme Mei-yu precipitation (MYR) over China for near-term and long-term climate is crucial.  This is because such information is essential for decision and policy makers to develop optimal strategies to mitigate any negative socioeconomic impact which could be caused by changes in MYR. While the performance of climate models has improved substantially over the past few decades, accurate prediction of MYR remains an open challenge. On the other hand, climate models often have a better representation of the large-scale climate modes (LSCMs) and many studies have suggested some LSCMs and MYR are related. A recent study has demonstrated the representation of MYR in climate models can be improved by using causality-guided statistical models (CGSMs) based on LSCMs causally related to MYR as predictors. However, the potential changes in these causal-physical drivers on (multi-)decadal timescale has not previously been considered. In this presentation, we present the preliminary results on the potential changes in causal-physical drivers, which govern MYR, on (multi-)decadal timescales. A potential application of such information for decadal prediction systems is also discussed.
Control of soil fertility from organic matter amendments and rotations
Authors: Putelat Thibaut , Whitmore Andrew P
Published: February 2023

Sustainable agriculture requires that soil fertility be optimal so as to maintain current levels of food production whilst also maintaining environmental quality and even improving both together. Like inorganic fertiliser, organic amendments such as manure or compost can increase crop yield and could partly replace artificial nitrogen, but need a multi-year strategy, because yields may decrease when amendments cease. Other measures to manage arable land such grass and clover leys used in rotation can also enhance crop yield and mitigate certain drawbacks of continuous arable cropping such as soil degradation. Because i. chemical fertilisers may become restricted to reduce GHG emissions and improve water quality, ii. organic amendments can be in short supply, and iii. ley-arable rotations can decrease the prevalence of cash crops, we are seeking optimal means for improving the fertility of land that takes account of the dynamics of the yield-enhancing benefits of organic amendments and leys alongside annual applications of artificial fertiliser.Using optimal control theory, we shall present a rational basis for combining applications of inorganic fertiliser and organic matter treatments of arable land to a sequence of crops grown in consecutive seasons that ensures maximum profit from crop production and improves soil fertility. Instead of a complex mechanistic approach, we use the empirical idea of a nutrient response curve, which is extended to include both the effects on yield of the nutrients themselves but also the long-lasting benefits of different types of organic matter management using ad hoc recurrence relations to model the carry-over of soil carbon and nitrogen from one season to the next.Based on this methodology, we will present an analysis of an organic manuring long term experiment at Rothamsted, using, in particular, eight years winter wheat yield data that followed organic matter treatments in the previous stage of the experiment; these treatments ceased before the wheats were grown. Nonlinear regression allowed for the selection and the parameter identification of a single nutrient response curve valid for different organic treatments (farmyard manure, straw, ley). Preliminary results of our control theory suggest that growing wheat for four years in rotation with one year of leys can both reduce the use of nitrogen fertilisers and maximise the farmer's annual profit compared to using either farmyard manure or straw as alternative organic amendments together with inorganic nitrogen fertilisers. We aim to study the impact of such optimal economic strategies on greenhouse gas emissions and nitrate leaching to shed new light on greener farm management strategies and the economic landscape supporting sustainable farming scenarios. Our methodology generalises the well-known single year break-even ratio used in nitrogen fertiliser recommendations to a multi-year metric for interventions such as manure application that persist for several cropping years. 
Mechanistic modelling of gross primary production and latent heat flux using SIF observations in different water and light limitation conditions
Authors: Beauclaire Quentin , De Cannière Simon , Jonard François , Longdoz Bernard
Published: February 2023

One of the most efficient ways to estimate carbon assimilation at the ecosystem scale is based on the observations of sun-induced chlorophyll fluorescence (SIF) from satellites coupled with empirical relationships between SIF and gross primary production (GPP). However, there is still a lack of knowledge about the influence of physiological and environmental factors on these relationships. Recently, a process-based light response (MLR) model was developed from the perspective of the light reactions of photosynthesis to mechanistically determine the ecosystem photosynthetic activity from SIF measurements above the canopy. In addition to GPP, the MLR model can also be used to predict the latent heat (LE) flux when coupled with a stomatal conductance model like the unified stomatal optimality (USO) model. The goal of this research is to calibrate and test the MLR-USO model, as well as evaluate its performance at the field scale.The MLR-USO model was used to estimate GPP and LE at the ICOS station in Lonzée, Belgium (BE-Lon), which was equipped with a field spectrometer (Fluorescence box –FLOX) installed above a winter wheat crop to measure SIF between February and July 2022. The application and evaluation of the coupled MLR-USO model at the canopy scale requires (i) to determine the value of the MLR model parameters, (ii) to calibrate the USO model on previous cropping seasons of winter wheat at BE-Lon, (iii) to calculate the broadband (640-850 nm) SIF emitted by all photosystems II (PSII) from in-situ measurements of directional observed SIF at 760 nm, and (iv) to compare GPP and LE estimates from the MLR-USO model with eddy covariance (EC) flux tower GPP and LE.The results of this study demonstrate that SIF at the canopy scale captured the dynamics of both water and carbon exchanges over a wide range of environmental conditions, including light and water limiting conditions. Consequently, the MLR-USO model performed well when compared to EC data (RMSEGPP=6.56 μmolm-2s-1 / RMSELE=22.79 Wm-1 at half hourly timescales and RMSEGPP=4.61 μmolm-2s-1 / RMSELE=26.75 Wm-1 at daily timescales). These results support the use of this integrated model containing both a stomatal conductance and a photosynthesis module as an important step towards a better understanding and quantification of carbon and water fluxes at the ecosystem scale, providing also key information for the interpretation of satellite-based SIF.
Eocene seismicity and paleogeography of the Central Crimea
Authors: Chizhova Ekaterina , Lygina Ekaterina A. , Pravikova Natalia  V. , Tveritinova Tatiana  Yu. , Krasnova Elizaveta A.
Published: February 2023

The nature of Cretaceous-Eocene boundary is one of the outstanding questions of Crimea Geology. The new data are presented to show that the Cretaceous-Eocene boundary can be established in the Central Crimea very accurately by using the method of quantitative genetic analyses including the Isotope Geochemistry. Integrated lithostratigraphic investigations and Isotope composition of Carbon/Oxygen were conducted on the Cretaceous -Eocene section of the western slope of Ak-Kaya mount (Belogorsk, Crimea). Four layers of different types of rocks were investigated, where the layer 1 and 2 belong to the Maastrichtian, 3 and 4 to the Eocene.The top of the Maastrichtian layer is characterized by a differently oriented fracture system, including large paleoseismic dislocations or a seismogenic trench. The fracture networks are connected and filled with material similar to the Eocene basal horizon including fragments of various sizes of Maastrichtian rocks.Five microfacial types of the collected rock samples were distinguished as a result of microscopic examination. Also X-ray phase analysis, δ13С and δ18О isotopic analysis and X-ray fluorescence analysis were made to specify and compare the mineral composition of Maastrichtian and Eocene rocks. These analyzes allowed to specify paleogeographic conditions. In addition, measurements of fractures in the Cretaceous–Eocene boundary deposits were made to determine the stages of deformation of the whole structure.As a result of the research, it was obtained:1) throughout the entire studied geological interval, sedimentation occurred in a shallow sea of normal salinity. However, conditions were probably more humid in the Eocene, based on lower salinity values.2) Three major stages of deformation were identified: pre-Eocene, Eocene, and post-Eocene.3) The average temperature of the formation of Maastrichtian rocks is 19-22°C, and Eocene rocks is 24-27°C. The increase in temperature up to 38°C during the formation of the Eocene basal horizon may be associated with the global climatic event EECO (Early Eocene Climate Optimum). The synchronicity of the formation of steep submeridional fractures and the basal horizon of the Eocene has been proved. It is shown that the Eocene deformation stage corresponds to the formation of paleoseismic dislocations during the main phase of tectonic activity in the Pontids (Eastern Turkey).
Toxicological consequences of sea-dumped munitions
Authors: Maser Edmund , Buenning Tobias , Strehse Jennifer
Published: February 2023

Since World War I, considerable amounts of warfare material have been dumped at seas worldwide. After more than 70 years of resting on the seabed the metal shells of these munitions are corroding, such that  different kinds of chemicals leak out and distribute in the marine environment. Energetic compounds such as TNT (2,4,6-trinitrotoluene) and its derivatives are known for their toxicity and carcinogenicity, thereby posing a threat to the marine environment. Toxicity studies suggest that chemical components of munitions are unlikely to cause acute toxicity to marine organisms. However, there is increasing evidence that they can have sublethal and chronic effects in aquatic biota, especially in organisms that live directly on the sea floor or in subsurface substrates. Moreover, munition-dumping sites could serve as nursery habitats for young biota species, demanding special emphasis on all kinds of developing juvenile marine animals.While the mechanism of toxicity and carcinogenicity of TNT and its derivatives occurs through its capability of inducing oxidative stress in the target biota, we found that TNT can induce the gene expression of carbonyl reductase in blue mussels. Carbonyl reductases are members of the short-chain dehydrogenase/reductase (SDR) superfamily and provide a defense mechanism against oxidative carbonyl stress as a consequence of reactive oxygen species (ROS) derived lipid peroxidation. After a bioinformatics approach and molecular cloning of the carbonyl reductase gene, we could show in both laboratory and field studies that TNT induces a strong concentration- and organ-dependent gene induction in the blue mussel. Carbonyl reductase may thus serve as a biomarker and early warning system for TNT exposure in marine systemsUnfortunately, munition chemicals may also enter the marine food chain and directly affect human health upon consuming contaminated seafood. While uptake and accumulation of toxic munition compounds in marine seafood species such as mussels and fish have already been shown, a reliable risk assessment for the human seafood consumer and the marine ecosphere is lacking and has not been performed until now. In this talk we present the landmarks for a risk assessment for the marine ecosphere as well as for humans who consume seafood contaminated with munition chemicals. We hereby follow the general guidelines for a toxicological risk assessment of food as suggested by authorities. 
Constraining sources and sinks of subglacial methane from the Greenland ice sheet using clumped isotopes
Authors: Adnew Getachew Agmuas , Schroll Moritz , Sapper Sarah Elise , Röckmann Thomas , Popa Maria Elena , Jørgensen Christian Juncher , Keppler Frank , van der Veen Carina , Sivan Malavika , Blunier Thomas , Christiansen Jesper Riis
Published: February 2023

The subglacial environment under the Greenland Ice Sheet (GrIS) is an active zone of methane (CH4) production and consumption (1). Recent studies have shown that the meltwaters are a net source of CH4 to the atmosphere (2), although its global significance remains unquantified. It is unknown how CH4 cycling and net emission is linked to the melting of the GrIS, which is expected to increase (3) as the Artic is warming four times faster than the global average. Evaluating the importance of this poorly known source for the atmospheric CH4 budget and its drivers requires a fundamental understanding of the amounts released, the sources and sinks and its age.Traditionally, measurements of the isotopic composition (13CH4 and 12CH3D) are used as fingerprints to identify sources and sinks of CH4. However, this method is limited due to the overlap of source signatures. For example, microbial methanogenesis in some environments can produce stable isotope compositions resembling thermogenic methane (4).  Furthermore, substrate isotopic composition, substrate limitation, the kinetics of methane production, transport, and oxidation substantially impact the stable isotope composition of microbially produced CH4. This complicates the interpretation of CH4 cycling and its physicochemical drivers.Clumped isotopes of methane, i.e. molecules of CH4 with two rare isotopes, (13CH3D and 12CH2DD), and its clumping anomaly (the relative difference between the measured value of 13CH3D and 12CH2DD and its stochastic distribution) provide additional insight to constrain CH4 sources and sinks. From the clumping anomaly, it is possible to calculate the formation temperature of methane (i.e. source of methane) if CH4 was formed in thermodynamic equilibrium. In the case of disequilibrium, the clumped signatures can be used to identify various kinetic gas formation and fractionation processes that are impossible to reconstruct from the bulk isotopic composition alone.In this study, we present for the first-time isotopic data of clumped CH4 and traditional isotopes of subglacial CH4 together with radiocarbon measurements (14CH4). These data are related to the isotopic composition of subglacial CO2 and mole fractions of the gases in the air and meltwater. Based on this data set, we will discuss the production and consumption pathways of CH4 in the subglacial environment and how it relates to diurnal and seasonal cycles of meltwater discharge.Reference:Christiansen et al. (2021). DOI: 10.1029/2021JG006308
Christiansen, J. R., & Jørgensen, C. J. (2018). DOI: 10.1038/s41598-018-35054-7
Ranlanen, et al. (2022), Commun Earth Environ, 2022. DOI: 10.1038/s43247-022-00498-3
Valentine et al. (2004). DOI: 10.1016/j.gca.2003.10.012
 
Long-term Earthquake Cycle along the eastern Altyn Tagh Fault, China
Authors: Pinzon Matapi Nicolás , Klinger Yann , Xu Xiwei , Liu Jing , Tapponnier Paul
Published: February 2023

Identifying earthquake recurrence times and slip distributions over the span of many seismic cycles is key to understand fault-rupture processes and to better assess the seismic hazard. In this study, we used three paleoseismological excavations along the Aksai segment of the Altyn Tagh Fault (ATF) to document preserved evidence of past earthquakes in the sedimentological record such as vertical offset, fault cracks, and folding. We integrated these findings with previous studies on the Annanba and Xorxoli segments in order to build a larger-scale rupture history of the ATF. We reported nine large paleo-earthquakes and three of these with ground rupture expression along the whole three segments (∼ 400 km). Based on a Bayesian approach we present 95-percentile range ages of 6149 – 5285 BC, 5296 – 4563 BC, 3026 – 2677, 2469 - 2254 BC, 2069 - 1964 BC, 1184 – 709 BC, 270 – 635 AD, 875 – 1325 AD and 1491 - 1741. Furthermore, we used high-resolution satellite imagery to measure horizontal offsets recorded in the morphology, which are associated with potential co-seismic deformation. We find that the mean recurrence time is 1171±425yr with a COV of ∼0.31 suggesting a quasi-periodic behavior with a characteristic slip motion based on the similar distribution of fault offsets. The last event seems to be strongly expressed in Xorxoli segment and also found along the Aksai segment, although we could not identify it along the Annanba bend. Whereas, the penultimate event and the two before this appear to well correlate across the Aksai, Annanba and Xorxoli segments. Thus, being strong candidates for the three largest and successive earthquakes along the ATF (roughly rupture longitude ≥ 350 km). Variations in the COVs along the eastern Altyn Tagh Fault accounts for the important control of local structural complexity and/or slip rate variations on the rupture behavior of major fault systems.
The climate impact of contrails from hydrogen combustion and fuel cell aircraft
Authors: Rap Alexandru , Feng Wuhu , Forster Piers , Marsh Daniel , Murray Benjamin
Published: February 2023

Aviation has been under increasing pressure in recent years to substantially cut its impact on climate. The International Air Transport Association (IATA) committed in October 2021 to achieve net-zero carbon emissions by 2050. Other similar ambitious targets have been set for aviation, all relying strongly on alternative fuel aircraft such as hydrogen combustion or fuel cells. A significant (i.e. 60%) proportion of the current aviation contribution to global warming is caused by non-CO2 effects, with contrail cirrus the largest of these effects. Here we perform and analyse the first calculation of the contrail cirrus effective radiative forcing (ERF) for fuel cell powered aircraft and one of the first calculations for liquid hydrogen combustion aircraft, comparing them with estimates for kerosene and sustainable aviation fuel (SAF).The exhaust mix of the hydrogen combustion in an aircraft gas turbine or hydrogen fuel cell aircraft is different to that of the current hydrocarbon fuels. This leads to a potential climate penalty due to the significant increase in associated water vapour emissions. We find that for liquid hydrogen combustion and fuel cell powered planes, the area of the globe covered by contrails is set to increase substantially (~70%) due to their additional water vapour emissions leading to more regions of the atmosphere becoming susceptible to contrail formation. However, the expected cleaner exhaust and corresponding increase in average contrail particle sizes lead to changes in contrail radiative properties. These changes result in a reduction in contrail cirrus ERF for liquid hydrogen combustion (~25%) and fuel cell (~20%) powered planes, compared to kerosene planes. SAF planes are expected to lead to a slight (~5%) increase in contrail cover, but a decrease (~20%) contrail cirrus ERF, compared to kerosene planes.In general, our analysis finds that changes in contrail cirrus ERF are relatively modest between fuel types, compared to the overall uncertainty in the ERF estimate itself. Some of this uncertainty stems from our representation of physical processes in contrails and further work is needed to look at the effects of alternative fuels on contrail ice crystal sizes, contrail lifetimes and aerosol-cloud interactions. 
Resolving Multiscale Magnetospheric and Radiation Belt Dynamics using Global MHD, Test Particle and Fokker Planck Simulations
Authors: Desai Ravindra , Eastwood Jonathan , Glauert Sarah , Horne Richard , Eggington Joseph , Heyns Mike , Archer Martin , Kelly Harley , Mejnertsen Lars , Chittenden Jeremy
Published: February 2023

The global magnetosphere represents an intricate and multi-scale system with dynamics occurring across scales ranging from metres to miles and milli-seconds to days. This represents a formidable challenge to understand, and differing plasma theories are typically applied to model the large-scale electromagnetic fields and the dynamics of the Van Allen radiation belts. This discretisation of plasma regimes, however, breaks down during extreme conditions when the magnetosphere becomes highly distorted and energetic particle dynamics vary rapidly across sub-drift timescales. To self-consistently model both short and long timescales, we combine global MHD and particle simulations with Fokker-Planck simulations to demonstrate how this presents a realistic and also necessary method to capture magnetospheric and radiation belt dynamics during severe geomagnetic storms. The global MHD simulations capture the large-scale modulations to the global magnetic and electric fields and the integrated particle simulations reveal intense acceleration processes during the compression phase and subsequent injections through the magnetotail. At relativistic energies, loss processes at low L shells are limited and the Fokker-Planck model reveals how newly accelerated radiation belt distributions evolve and persist over extended time periods. Modelling this flow of energy from the solar wind through to ring current and radiation belt populations, across both short and long time-scales, requires detailed observational constraints and we discuss how upcoming space missions will help us to holistically constrain energy transfers through our puzzling magnetosphere. 
Assessing lake and reservoir storage change from remote sensing data at a global scale
Authors: Fatras Christophe , Andral Alice , Augot Jérémy
Published: February 2023

Lakes and reservoirs monitoring is of sheer interest, as in-situ gauging station coverage is dwindling at a global scale. Water storage change show the impact of not only domestic consumption, low water maintenance in rivers or crop irrigation, but also the impact of climate change. In this frame, different approaches are explored in this study to be able to follow from space remote sensing data the lake storage change, either from water height or surface.For the ESA CCI Lake Storage Change option, we focus on a few lakes distributed around the world to establish a methodology suitable at a global scale to different lake behaviors. In particular for highly varying water bodies, the automatic production and use of hypsometric curve is investigated This approach is yet suitable for volume variations only.Complementary to this first approach, an image inpainting algorithm applied to digital elevation models around water bodies is developped to assess their total bathymetry (either for lake or reservoir) where the pixels to be reconstructed are the ones underneath the lake surface. The first results show encouraging estimations that may lead in the near future to the assessment of total water volume of lake and reservoir at a global scale. With the recent launch of SWOT that will provide an unprecedented coverage worldwide, the estimation of global water storage change has a bright future.
Detecting and characterizing the hillslope to channel transition in high erosion rate, bedrock landscapes
Authors: Lurin Aude , Marc Odin , Meunier Patrick , Carretier Sébastien
Published: February 2023

Channel networks exert a key control on drainage basins shape and dynamics in mountainous landscapes, including the transfer of water and sediment throughout basins, and thus hydrosedimentary hazards. Landscape dissection by channels results from the competition between hillslope processes and channelized erosion processes such as overland flow or debris flows. Although the competition between fluvial processes and hillslope processes has been modeled in simple cases, more data is still needed to constrain the localization and characteristic of this transition, especially in channels where debris-flows occur. High resolution LiDAR DEMs open new perspectives for the extensive extraction of channel heads. Several channel extraction methods exist but none is yet robust on fast eroding landscapes where channels are not always fluvial and sometimes initiate in rough bedrock areas.Therefore we developed the CO²CHAIN method which identifies the hillslope to channel transition in drainage basins based on relative changes of local and upstream measures of flow convergence. We calibrate CO²CHAIN by fitting its results to channel head mapping made by geomorphologists on four contrasted basins in the United States and France. Compared to state-of-the-art channel extraction methods, and without any recalibration, it achieves similar and higher accuracy in moderate and high erosion-rate basins, respectively.This allows us to identify the first order  channels (the most upstream part of mountain channels) to better understand how their morphology (slope, minimum drainage area, length) are linked to catchment mean erosion rates. We applied our method to a few LiDAR DEMs of mountain catchments with varied mean erosion rates and where debris flows have been identified. It appears that,  where channels begin, the drainage area and  slope  are correlated and this correlation depends on the catchment mean erosion rate and the local hilltop curvature. In order to understand what controls the transitions between hillslopes and debris flow channels, we also studied preliminarly the distribution of hillslope length and slope gradient and of channel gradient  throughout the catchments. This could give us insight into the processes shaping the bedrock channels and allow us to test long-term geomorphic models for debris flow erosion.