bluuebunny/crossref_metadata_2025 huggingface dataset:
Are all lineaments the surface expression of faults and fractures? – A novel analysis using tunnel face mapping data from Norwegian road tunnels
Authors: Torgersen Espen , Arctander Karoline , Redfield Thomas F. , Svendby Anne Kathrine , Dichiarante Anna Maria , Arntsen Mari Lie
Published: March 2024

Lineaments are elongated elements in spatial data such as valleys and ridges on topographic maps, or linear lows and highs in aeromagnetic data. Topographic linear depressions (topolineaments) are generally considered as the morphological expressions of easily erodable, elongated rock bodies situated within a mechanically stronger rock mass. In most circumstances topolineaments are even directly interpreted as faults and fractures, which forms the basis for lineament analysis study to understand brittle deformation patterns. However, topolineaments may also be formed by other tectonic and non-tectonic causes, such as alternating layers, foliation traces, dikes etc., or river- and glacial erosion not controlled by any bedrock features. This mix of potential causes begs the question: “How robust is actually lineament analysis for characterizing and quantifying faults and fractures?”. Testing the topolineament vs. fracture-relationship is not straight forward since topolineaments are usually occupied by rivers or creeks and covered with colluvium, which prevents direct observation of rock types and bedrock structures.Underground excavations allow for continuous logging of bedrock types, rock mass quality and fracture density and orientations, which is done routinely at tunnel face during tunnel construction. Here we make use of such underground data from a large dataset of Norwegian road tunnels to compare the position of topolineaments spatially and statistically with rock fracture density and orientations in the subsurface. The tunnel dataset comprises data from across Norway in areas with widely varying bedrock geology, tectonic evolution, and geomorphology (e.g. etched surface, alpine, lowlands), which allow for an evaluation of the robustness of lineament analysis in various settings. Topolineaments are acquired using a newly developed algorithm (OttoDetect) run on both 10x10m and 50x50m resolution digital elevation models. The algorithm ensures that tunnel data is compared to a homogeneous and reproducible lineament dataset without operator or hillshade illumination biases.Preliminary results from tunnels in areas with etched geomorphology show that c. 75% of all topolineaments correspond to weakness zones in the bedrock (i.e. very high fracture densities/very low rock mass quality compared to the surroundings). Hit rate increases for longer lineaments, which generally correspond to thicker fault zones. At the same time, only up to c. 60% of all weakness zones mapped at tunnel face can be spatially associated to a topolineaments, which demonstrate that significant brittle deformation is not expressed as topolineaments. Further analysis will be carried out to build a statistically robust dataset on the validity of lineament analysis.
Mediterranean Climate Regions in CMIP6 experiments: assessment of future changes and associated uncertainties
Authors: Cherchi Annalisa , Alessandri Andrea , Lembo Valerio , Gelsinari Simone , Renwick James
Published: March 2024

The mean climate characteristics of the Mediterranean region with temperate, wet winter and warm (or hot) dry summer is common to other regions of the world, like the west coast of North America, central Chile, the far southwest tip of Southern Africa and southwest Australia, which are all identified as Mediterranean climate regions (MCRs). Following from the Koppen-Geiger classification of climates, they share similar location and lie on the western edge of continents in the subtropics to mid-latitude thus being overall transition areas between wet and dry climates. In a previous work, with a probabilistic approach, we have quantified the risk of a poleward shift of MCRs, mostly over the Mediterranean region and western North America, with the equatorward margins replaced by arid climate type using CMIP5 21st century projections.Following on from the above and using newly available CMIP6 simulations we have designed an update of the assessment of future climate changes in MCRs. The objective is to identify how MCRs are projected to change in CMIP6 simulations either in terms of hydroclimate conditions and of expansion or retreat of the areas considering the high impact these changes may have on water resources, ecosystem and human livelihood over these vulnerable climate regions. On top of the overall picture of hydroclimate changes over the regions with commonalities and differences, as expected from current dynamical understanding, we will provide an evaluation of the uncertainties in the projections and estimates of the models’ reliability in representing observed past changes. 
Large-scale and High-resolution Frontal Ablation Estimates in the Arctic through a Machine Learning Approach
Authors: Pyles Dakota , Gourmelon Nora , Christlein Vincent , Seehaus Thorsten
Published: March 2024

Frontal ablation is an important component of tidewater glacier mass loss, however, high temporal resolution estimates have remained elusive due to difficulty in reliably capturing terminus position changes with satellite imagery. Recent developments in machine learning-based radar image segmentation to automatically delineate glacier fronts has opened an opportunity to calculate frontal ablation over fine timescales. Through segmentation of Sentinel-1 synthetic aperture radar image sequences, we aim to quantify seasonal and annual frontal ablation across several Arctic regions, using a deep learning-based terminus segmentation algorithm. Svalbard, an Arctic region characterized by variable and complex glacier and fjord geometries, will serve as a methodological test site before expanding the scope to the Canadian Arctic, Greenland periphery, and Russian Arctic, or ~1400-1500 marine-terminating glaciers in the Northern Hemisphere. The derived frontal ablation information is valuable to climate and glacier models, which could benefit from high-resolution reference data, resulting in improved calibrations and parameterizations. Future project efforts will include quantifying total mass budget for all glaciers in the study by integrating frontal changes, ice discharge calculations from ice thickness and surface velocity products, and climatic mass balance data. To identify and evaluate external drivers of glacier change, the frontal ablation and mass balance products will be combined with modeled and observational atmospheric, oceanic, and sea ice data. Through multivariate statistical analyses between these Earth system datasets and mass balance components, we look to provide an improved understanding of dynamic tidewater glacier processes, their spatio-temporal variability, and the influence of glacier geometry on observed changes throughout the Arctic.
The influence of environmental factors on the actual evapotranspiration of Artemisia ordosica 
Authors: Zhang Zaiyong , Feng Qi , Gong Chengcheng , Zhu Meng , Liu Wei , Zhang Jutao , Li Anyuan
Published: March 2024

Artemisia ordosica can prevent desertification and increase carbon sequestration, and it has been extensively planted in the Mu Us Desert, China. Evapotranspiration (ET) plays an important role in the survival of Artemisia ordosica. However, the controlling factors of ET remain unknown. To investigate the influencing factors on the actual evapotranspiration, we set up a weighing lysimeter with Artemisia ordosica in the Mu Us Desert. We collected data of air temperature (Ta), net radiation (Rn), wind speed (WS), soil moisture (θ), vapor pressure deficit (VPD), and heat flux (HF). The multiple linear regression model was used to quantify the influence of the six environmental factors on the ET. In addition, we applied the boosted regression tree (BRT) method to quantify the relative contribution of these environmental factors to ET. Our results show that annual ET was 444.46 mm, which was mainly influenced by the VPD during the dry season and Rn during the rainy season. This is different from the previous results which emphasized the importance of θ and Ta. The BRT results show that VPD and Rn are the most contributors to ET in the research area. In addition, ET significantly decreased when the soil moisture was less than 0.063 cm3/cm3. ET can increase by an average of 90% after a rainfall event. Our results have significance for the hydrological cycle and ecological environment protection.
Optimal factor combinations selection in typhoon-induced landslides susceptibility mapping using machine learning interpretability
Authors: Wang Fei , Zhou Liwei , Liu Yanlin , Chen Fei
Published: March 2024

Typhoon is a key dynamic factor triggering landslides. In view of the fact that the previous susceptibility evaluation models rarely consider the interaction between typhoon and static factors, carry out research on the optimal dynamic and static factors combination of typhoon-induced landslides susceptibility. Using the interpretability of machine learning, the importance ranking of dynamic and static factors is carried out to identify key impact factors. On this basis, the importance of static factors under the influence of typhoon is compared, and the interaction between typhoon and static factors is analyzed. Finally, the optimal combination of dynamic and static factors is proposed by using k-fold cross-validation method and taking the average descent accuracy as the index. The results show that the importance of the key influencing factors of typhoon-induced landslide from high to low mainly includes: elevation, NDVI, road and other factors; the addition of typhoon and rainstorm factors significantly increased the importance of factors susceptible to typhoon, such as water system and vegetation, with an increase rate of 24.8-151.7 %. The optimal dynamic and static factors combination of typhoon rainstorm landslide includes all key static factors and four dynamic factors, among which the dynamic factors are: maximum sustained wind speed, rainfall, distance from typhoon center and near gale wind circle radius. The results of ROC curve verification show that the selection of the optimal factor combination can increase the accuracy of the evaluation model by 1.5%-3.5%, which can significantly improve the accuracy and rationality of the susceptibility mapping of typhoon-induced landslides.Keywords: Impact factor, Typhoon, Landslides susceptibility, Interpretability of machine learning.
Mineral oil, movement and monitoring ecosystem health 
Authors: Reilly Katie , Lynch Iseult
Published: March 2024

Commercial formulations of mineral oils and other forms of lubricants can be released into the environment during the application, use and lifetime of a product. Mineral oil formulations in combination with other materials such as graphene and silicone nanomaterials can be used to prolong the life and use of sporting equipment, such as bikes and boats. Through this, excess material can be released into the environment during application, or during the products subsequent use. Oil is a challenging pollutant to monitor and assess in aquatic environments due to the hydrophobic nature which makes the distribution and movement of oil different to other types of aquatic pollutants, however an important pollutant to understand with the use of oil and advanced material formulations being developed and currently used.In this study, we explored the impacts that different formulations of mineral oil (with and without graphene/silicon) can have on the keystone freshwater species Daphnia magna. Daphnia have been historically used for toxicity testing of chemicals and other materials such as microplastics and nanomaterials, in addition to being used in field studies as indicators of good environmental health. Due to Daphnia’s well established and broad ranging use, they are an excellent species to explore emerging contaminants to compared to the previously established range of responses. Here, Daphnia were exposed to different formulations and concentrations of mineral oil and their acute toxicity was initially assessed, before subsequent studies were undertaken to determine how oil can impact the Daphnia’s behaviour. This was done by recording the Daphnia movement over a 24 hour period and assessing both the vertical migration in the test vessel, in addition to their movement in a 10mL well (in a multiwell plate) for stress indicators (i.e. more spins in the water are behavioural indicators of higher stress). Daphnia are keystone species, and link the algae (primary producers) to high levels of the food web, therefore impacts on their movement could have wider reaching consequences for aquatic ecosystems. Through evaluating Daphnia movement and interaction with the oil in different test vessels we can also explore how they might influence the transport and mixing of oil into their environment and impact the legacy timeframe of oil contamination.
An overview of collaborative field campaigns, calval and community science activities enabled through the ESA-NASA Joint Program Planning Group
Authors: Davidson Malcolm W. J. , Drinkwater Mark , Kaye Jack
Published: March 2024

The US National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) created a Joint Program Planning Group (JPPG) in 2010 to enhance coordination between NASA and ESA on current and future space Earth Observation missions. One of the three sub-groups of the JPPG is dedicated to collaboration in field measurement campaigns, mission and product calval and more recent collaborative EO community science projects.Since 2010 the JPPG has initiated or informed numerous airborne field campaigns to help develop and document the scientific objectives, develop geophysical retrieval algorithms and provide calibration and/or validation for present and/or future satellites to be operated by NASA, ESA, and its partners. The activities address an underlying need to demonstrate unambiguously that space-based measurements, which are typically based on engineering measurements by the detectors (e.g. photons), are sensitive to and can be used to reliably retrieve the geophysical and/or biogeochemical parameters of interest across the Earth and validate mission design. Such campaigns have included as diverse subjects as atmospheric trace gas composition over the western US, solar induced fluorescence over the Eastern United States, wind profiles over the north Atlantic, vegetation canopy profiles in Gabon, and sea ice and ice sheet properties in the Arctic and Antarctic. The collaborative field campaign and calval activities have helped use of surface-based, airborne, and/or space-based observations to develop precursor data sets and support both pre- and post- launch calibration/validation and retrieval algorithm development for space-based satellite missions measuring our Earth system.The generation of consistent, inclusive, community-based assessments of Earth system change through integrated analyses of these different data sets is also a critically important process in the challenge of documenting Earth system change. To assist in this process the JPPG has supported collaborative community efforts including three installments of the Ice Mass Balance Intercomparison Experiment (IMBIE; two completed, one ongoing), the NASA-ESA Snow on Sea Ice Intercomparison (NESOSI), and the Arctic Methane and Permafrost Challenge (AMPAC).In this talk a review of JPPG activities and their results, as well current plans for future collaborations including campaigns will be provided. 
Synthesising homogeneous carbonate reference materials for in situ U–Pb calcite geochronology
Authors: Szymanowski Dawid , Kueter Nico , Guillong Marcel , Tavazzani Lorenzo , Akker Ismay Vénice
Published: March 2024

Recent years have seen a rise in applications of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to elemental and isotopic analysis of a wide range of geological materials, with a true explosion of in situ geochronology. Standardising such analyses relies on a homogeneous matrix-matched primary reference material (RM) whose ablation, transport and ionisation characteristics will result in fractionating elements and isotopes in the same way as in the unknown of interest.One of the current frontiers of LA-ICP-MS geochronology – U–Pb dating of carbonates – suffers from a lack of such a material. Because the currently used primary RMs (e.g. WC-1 [1]) are heterogeneous in both age and U/Pb ratio, isotopic ratios are corrected on an isochron (whole-sample) basis rather than for each individual analytical spot, which imposes excess uncertainty on all U–Pb ages obtained this way. The U–Pb carbonate geochronology community is thus in urgent need of homogeneous reference materials for wide distribution. Ideally, such a RM should match the ablation behaviour of the unknown carbonate and consequently all matrix effects, including the amount and depth progression of inter-element laser induced elemental fractionation (LIEF), can be corrected directly, as is standard in e.g. zircon U–Pb geochronology.We present a method for preparing synthetic RMs that uses a natural rock starting material which is milled to nano-powder, homogenised, and recrystallised using high-pressure, high-temperature apparatuses. In this way, natural sample heterogeneity is removed through milling, while textural coarsening is aimed at generating ablation behaviour similar to that of routine unknown samples.Initial tests of synthetic calcite materials demonstrate the ability to achieve homogeneity at the spatial scale of a typical LA-ICP-MS laser spot size (80–110 µm typical for calcite U–Pb), while the ablation rate and LIEF are comparable to those of a range of commonly used calcite RMs. This suggests that experimental manufacturing of recrystallised carbonate is a promising avenue to obtain primary RMs that will allow spot-by-spot correction of LIEF in U–Pb analyses, thereby significantly reducing the reliance on heterogenous natural calcite RMs and improving the precision and accuracy of this analytical method.Finally, this approach may serve as a blueprint for larger-scale production of primary RMs for a variety of matrices and isotopic systems for which there are no natural RMs characterised by the necessary homogeneity or availability.[1] Roberts, N.M.W., et al., Geochemistry Geophysics Geosystems, 2017, 18(7): 2807-2814.
Recent and future variability of the ice-sheet catchment of Jakobshavn Isbræ, Greenland
Authors: Løkkegaard Anja , Colgan William , Aschwanden Andy , Khan Shfaqat Abbas
Published: March 2024

Glacier catchments, refer to the upstream area of an ice sheet that is being drained by a single glacier. Delineated catchments are used to study the mass balance of individual glaciers or conglomerates of glaciers. Single glacier basin mass balance studies allow us to gain an understanding of the controlling processes and monitor changes of individual glaciers. Such studies, however, are highly sensitive to how the surface mass balance collection area is delineated for comparison with the grounding line ice discharge. Frequently, catchments are assumed to be temporally invariant, which can impact studies of basin wide mass balance on longer time scales.
We have explored variations in present day delineated area, and potential temporal variability, in the catchment of Sermeq Kujalleq, or Jakobshavn Isbræ, Greenland. Five observation based, ‘present day’ catchment delineations are evaluated along with delineations based on modeled surface velocities from a sixteen-member ensemble of ice-sheet models within the Ice Sheet Model Intercomparison Project for CMIP6 (ISMIP6). 
The ISMIP6 ensemble mean area was found to be ~5.4% larger than the mean of the observed catchments. Observed and modeled ensemble spreads were comparable, ±12.3% and ±15.4%. Hence, models are able to delineate the present day catchment with the same degree of uncertainty as observational methods. The ISMIP6 ensemble mean catchment area shows temporal variation, increasing ~4% from 2015-2100, primarily as the southern catchment boundary migrates southward. This is interpreted as Jakobshavn Isbræ exhibiting dynamic piracy, redirecting ice away from adjacent land terminating glaciers. 
Repeat velocity observations in the catchment suggest a recent acceleration in ice flow ~100 km inland from the terminus of Jakobshavn Isbræ. This observed acceleration is not believed to be attributable to changes in meltwater lubrication nor driving stress changes. Instead it is theorized that changes in the basal temperate ice layer could be the cause of the acceleration. The trend in simulated ensemble velocity and azimuth values over the 2015-2100 period is evaluated against trends from the recent velocity observations. The ISMIP6 ensemble is underestimating the observed regional acceleration, not fully capturing the deep inland dynamic response of the ice sheet to the recent climatic changes.
Flood Segmentation with Optical Satellite Images Under Clouds Using Physically Constrained Machine Learning
Authors: Campo Chloe , Tamagnone Paolo , Gallion Guillaume , Schumann Guy
Published: March 2024

Timely and accurate flood map production plays a key role in enhancing effective flood risk assessment and management. Satellite imagery is frequently employed in flood mapping as it can capture flooding across vast spatial and temporal scales. Floods are usually caused by prolonged or heavy precipitation correlated with dense cloudy conditions, posing challenges for accurate mapping.The Synthetic Aperture Radar (SAR) active sensor is a popular option due to its feature of being weather agnostic, penetrating through clouds, fog, and darkness, providing images for the detection of flooded areas regardless of the weather conditions. However, this advantage is at the expense of low temporal resolution and double bounces in urban and heavily vegetated areas, which increase signal processing difficulty and misinterpretation. Passive microwave radiometry has also been explored for flood mapping, but its coarse spatial resolution limits the utility of the resulting flood maps. Multispectral optical imagery offers a balanced trade-off between temporal and spatial resolutions, with the only limitation that the acquired images might be hindered by the presence of clouds. Capitalizing on the utility of optical imagery, FloodSENS, a machine-learning (ML) algorithm consisting of a SENet and UNet, precisely delineates flooded areas from non-flooded areas in clear and partially clouded optical imagery. Although the current algorithm version enforces flood delineation involving topography-derived information in the ML processing, it is not capable of detecting floods under clouds; thus, we propose a new iteration of FloodSENS that utilizes auxiliary data in post-processing to improve the inferred flood maps.The post-processing pipeline utilizes the inferred flood map generated by FloodSENS and the Digital Elevation Model (DEM) of the target area to accurately delineate the flood extent beneath clouds, adhering to the physical constraints in the topography. First, Pixels at elevations equal to or lower than the water level are designated as flooded pixels. These pixels are further refined with geoprocessing to establish hydrological connectivity and topographic consistency. Pixels that are both marked as flooded and hydrologically connected are confirmed as flooded pixels for the final flood map.The post-processing proves essential in tropical and subtropical regions that frequently have high cloud cover during the monsoon seasons, making it imperative to map the affected areas during flooding events. The FloodSENS detection with the post-processing pipeline has been tested on partly clouded optical imagery obtained from the 2023 autumn flooding in southern Somalia.
Marine basalt complexes within reach of Europe – quo vadis?
Authors: Kopf Achim , Dunger Melanie , Elfil Mohamed
Published: March 2024

Carbon Dioxide Removal (CDR) approaches are essential to achieve the Paris 2015 global warming targets, as emphasized by the Intergovernmental Panel on Climate Change (IPCC) in their reports from 2021 onwards. With European legislation and ethical constraints in mind, a desirable approach to contribute to meeting ambitious climate goals would require to find safe, effective and sustainable storage sites on European territory, e.g. to avoid additional CO2 footprint for transportation or other processing steps needed.Given that the (admittedly substantial) storage capacity of Mesozoic sandstones forming the continental socket of wider parts of Europe (with a potential to host 270 Gt of carbon dioxide) has been widely accepted, there still remain doubts that these deep, warm reservoirs are the ideal place for storage of supercritical CO2, in particular since the overburden strata are heavily fractured and far less impermeable than what would be ideal and safe – let alone the elevated temperatures in several kilometres where Buntsandstein formations encounter conditions where carbon dioxide remains in its supercritical state for geological times. In contrast, oceanic basalts have been demonstrated to host CO2 both as structural (pore volume) and mineral (precipitation as carbonate minerals) traps in a sustainable manner. In large water depth the CO2 is stable as pure carbon dioxide, and when dissolved in seawater, the carbonated equivalent is heavier than pure seawater and unlikely to escape.With that in mind various European regional scenarios have been (re-)visited in order to assess feasibility and potential of storage. We have focused on the North Atlantic Volcanic Province (NAVP) with an estimated volume of extrusives close to 1.8 Mill. km3. The NAVP comprises various mafic and ultramafic regions between Iceland, the UK and Norway, including ocean crust, vesicular basalt and other igneous rock originating from the opening of this part of the Atlantic Ocean. We identified various corridors using ArcGIS Pro in combination with the Carbfix Mineral Storage Atlas and quantified the storage potential and associated cost in case CDR was to be carried out in these areas. Despite the large uncertainty in such numbers, the study serves to compare (among others) the Vøring and Møre basins, the Aegir ridge, Shetland and Faroer islands and neighbouring facies, and the Rockall basin and ridge. Farther from industrial centres we also investigated Iceland and the Reykjanes ridge. The work carried out is part of the AIMS3 project as part of the research mission CDRmare (www.cdrmare.de).
In-situ treatment of nitrate polluted groundwater by chemoautotrophic denitrification: flow-through tank experiments
Authors: Seeholzer Adrian Simon , Wunderlich Anja , Steib Ruben , Einsiedl Florian
Published: March 2024

Nitrate in groundwater can be converted microbially into N2. However, the lack of anoxic conditions (oxygen concentrations < 50 μmol/L) in the aquifer linked with the limitation of microbial available organic and inorganic electron donors may lead to insufficient denitrification in aquifers and nitrate concentration above the drinking water limit of 50 mg/L can be observed. In view of the increasing drinking-water scarcity associated with climate change and the continuing increase in nitrate concentrations in near-surface aquifers, it is urgently necessary and prudent to develop practicable and cost-effective methods to reduce nitrate to harmless N2.Faced with the increasing nitrate pollution in groundwater, we want to develop a new cost-effective in-situ remediation technology by hydrogen/methane coupled denitrification. We hypothesize that the simultaneous injection of the two water soluble electron donors H2 and CH4 into groundwater may significantly enhance the rate of nitrate consumption by activation of denitrifying chemolithoautotrophic microorganisms that are already present in the groundwater.Here we show the experimental set-up of the 2D-model aquifer (6 m x 1,8 m), the sampling strategy and show first results of the methane injection experiment. Measurements are performed along the flow direction and at several depths. Concentration profiles and stable isotope composition of methane (δ13C) and nitrate (δ15N) linked with oxygen concentrations shed light on the hydrogen-methane coupled denitrification potential in the model aquifer.
Continuum models of dykes: a comparison to discrete fracture models
Authors: Li Yuan , Davis Timothy , Pusok Adina , Katz Richard
Published: March 2024

Dykes are fluid-filled fractures that transport melt within the lithosphere. Their presence impacts lithospheric stresses and hence the forces of plate tectonics. Accurate representation of dykes in geodynamic models is crucial for modelling the dynamics of rifting. Li et al. (2023) approximated dyking as plastic tensile failure in a two-phase continuum with a poro-viscoelastic—viscoplastic (poro-VEVP) rheology. Li et al. only partially validated this model approach, and hence the extent to which it approximates a natural fracture remains unclear. In this study, we extend the comparison between our continuum formulation and the widely accepted theory of Linear Elastic Fracture Mechanics (LEFM) to the case of a buoyancy-driven dyke (Roper and Lister, 2007). We achieve this through detailed consideration of the dynamics and energetics. Comparing the dynamics of the continuum and LEFM models is challenging due to their differing assumptions and the limitations of finite-difference numerical solutions. The continuum model treats the liquid phase as porous flow, while the LEFM model assumes a lubricated channel flow inside of an open fracture. A drawback of numerical computations is that the grid size can exceed the dyke width. In fact, one shortcoming of the previous computational framework is that the dyke width can grow to several grid cells, which further complicates the comparison. To overcome these challenges, we adjust both models to have the same geometry and mechanics: (1) we incorporate in the continuum model an anisotropic permeability treatment based on plastic strain components; (2) we introduce an intermediate 'poro-fracture' model that is a modified LEFM model for porous channel flow. Our results show that the poro-VEVP model converges to the LEFM poro-fracture model at a toughness value that is large relative to natural rock and at a propagation speed that is slow relative to the standard LEFM formulation. Firstly, we attribute the slow propagation speed in the continuum model to the high Darcy’s drag force, which can be improved by augmenting the permeability. Secondly, we show that plasticity in the continuum model relates quantitatively to the toughness in the fracture model. It is evidenced by the good agreement between the two models in stress field prediction and also the dyke porosity profiles when a specific toughness value is applied to the fracture model. Intriguingly, this toughness is derived from equating the total energy dissipation rate in the continuum model to the energy required to open a fracture, thereby establishing an energy-based connection between the two models.ReferencesLi, Y., Pusok, A., Davis, T., May, D., and Katz, R., (2023). Continuum approximation of dyking with a theory for poro-viscoelastic–viscoplastic deformation, Geophysical Journal International.Roper, S.M. and Lister, J.R., (2007). Buoyancy-driven crack propagation:the limit of large fracture toughness. Journal of Fluid Mechanics.
Conceptual framework for exploring riverine macroplastic fragmentation
Authors: Liro Maciej , Zielonka Anna , van Emmerik Tim H.M.
Published: March 2024

     Field-based information on the rates of macroplastic fragmentation in rivers is currently mostly unavailable. However, obtaining such data in future research is crucial to understanding the production of secondary micro- and nanoplastics in rivers, the transfer of these harmful particles throughout the natural environment, and assessing the risks they pose to both biota and human health.     To support future experimental works addressing this gap we developed a conceptual framework which identifies two types of riverine macroplastic fragmentation controls: intrinsic (resulting from plastic item properties) and extrinsic (resulting from river hydromorphology and climate)[1].  First, based on the existing literature, we identify the intrinsic properties of macroplastic items that make them particularly prone to fragmentation (e.g., film shape, low polymer resistance, previous weathering). Then, we conceptualize how extrinsic controls can modulate the intensity of macroplastic fragmentation in perennial and intermittent rivers. Using our conceptual model, we hypothesize that the inundated parts of perennial river channels—as specific zones exposed to the constant transfer of water and sediments—provide particular conditions that accelerate mechanical fragmentation of macroplastic resulting from its interactions with water, sediments, and riverbeds. The unvegetated areas in the non-inundated parts of perennial river channels provide conditions for biochemical fragmentation via photo-oxidation. In the non-inundated sections of perennial river channels, unvegetated areas create conditions favoring biochemical fragmentation through photo-oxidation. In intermittent rivers, the entire channel zone is hypothesized to support both physical and biochemical fragmentation of macroplastics, with mechanical fragmentation prevailing during periods of water flow.     Our conceptualization can support planning of future experimental and modelling work aimed at the direct quantification of plastic footprint of macroplastic waste in different types of rivers.The study was completed within the scope of the Research Project 2020/39/D/ST10/01935 financed by the National Science Center of Poland.References1. Liro, M., Zielonka, A., van Emmerik, T.H.M., 2023. Macroplastic fragmentation in rivers. Environment International 180, 108186. https://doi.org/10.1016/j.envint.2023.10818
Manifold Embedding Based on Geodesic Distance for Non-stationary Subsurface Characterization Using Secondary Information
Authors: Park Eungyu
Published: March 2024

In geological characterization, the traditional methods that rely on the covariance matrix for continuous variable estimation often either neglect or oversimplify the challenge posed by subsurface non-stationarity. This study presents an innovative methodology using ancillary data such as geological insights and geophysical exploration to address this challenge directly, with the goal of accurately delineating the spatial distribution of subsurface petrophysical properties, especially, in large geological fields where non-stationarity is prevalent. This methodology is based on the geodesic distance on an embedded manifold and is complemented by the level-set curve as a key tool for relating the observed geological structures to intrinsic geological non-stationarity. During validation, parameters ρ and β were revealed to be the critical parameters that influenced the strength and dependence of the estimated spatial variables on secondary data, respectively. Comparative evaluations showed that our approach performed better than a traditional method (i.e., kriging), particularly, in accurately representing the complex and realistic subsurface structures. The proposed method offers improved accuracy, which is essential for high-stakes applications such as contaminant remediation and underground repository design. This study focused primarily on two-dimensional models. There is a need for three-dimensional advancements and evaluations across diverse geological structures. Overall, this research presents novel strategies for estimating non-stationary geologic media, setting the stage for improved exploration of subsurface characterization in the future.
Tracking the sources of atmospheric microplastic using FLEXPART v.
Authors: Bucci Silvia , Tatsii Daria , Evangelou Ioanna , Bakels Lucie , Stohl Andreas
Published: March 2024

An emerging number of studies highlighted the presence of microplastic in the atmosphere all over the world. The presence of such particles has been observed at the poles, in the marine atmosphere above the surface of the oceans, in clouds, on the fresh snow of high mountains and high concentrations has been observed in the atmospheric fallout in densely populated areas. Despite so, the main sources of atmospheric microplastic are still not well characterized and there are high uncertainties in the attempts of estimating their relative contributions. In addition, the peculiar shape of some of these particles, e.g. the very elongated fibers, complicates tracking their atmospheric transport. In this work, we explore the contribution of different sources adopting a Lagrangian approach to analyze the existing timeseries of microplastic concentrations. To do so, we exploit the new version of the Lagrangian model FLEXPART v11 (L. Bakels et al. 2024, in preparation), which also has the capability of considering the differences in the atmospheric lifetimes of irregular particles such as flattened or elongated plastic film or fibers (D. Tatsii et al. 2023). The results will highlight the areas of main emission for the regions of observations and help advance in our understanding of the sources of atmospheric microplastic pollution.
Influence of changing sea ice parameterisation on Southern Ocean  carbon uptake and export production
Authors: Torsvik Tomas
Published: March 2024

The Southern Ocean (SO) plays a key role in global carbon and nutrient cycles, as the SO overturning circulation feeds into both deep-water formation (lower branch) and Subantarctic intermediate and mode water formation (upper branch). While the air-sea CO2 balance is influenced mainly by deep-water formation, global export production is more sensitive to intermediate and mode water formation, giving rise to the concept of a SO biogeochemical divide [1]. Sea ice formation, transport and melting plays a prominent role in the transformation of buoyancy for both the upper and lower branches of the overturning circulation [2]. Hence, changes in sea ice parameterisation have potential for substantially altering carbon uptake and export production in global Earth System Models (ESMs).Global ESMs seek to simulate physical, chemical and biological processes that are relevant for the evolution of global climate, including fluxes of greenhouse gasses and aerosols between the atmosphere and ocean. The air-sea gas exchange is determined by the difference in concentration across the air-sea interface, and a gas transfer velocity that is specific for the gas in question. However, the air-sea gas exchange is inhibited by the presence of sea ice. A modified formula proposed by Steiner et al. [3], accounting for cracks and leads in the sea ice, has recently been  implemented in the Norwegian Earth System Model NorESM2 [4]. In this study we investigate how the change in this sea ice parameterisation influences the carbon uptake and export production associated with the Southern Ocean overturning circulation.REFERENCES[1] I. Marinov, A. Gnanadesikan, J. R. Toggweiler and J. L. Sarmiento, "The Southern Ocean biogeochemical divide", Nature, Vol. 441, 964-967, 2006. DOI: 10.1038/nature04883[2] R. P. Abernathey, I. Cerovecki, P. R. Holland, E. Newsom, M. Mazlo and L. D. Talley, "Water-mass transformation by sea ice in the upper branches ofthe Southern Ocean overturning", Nature Geoscience, Vol. 9, 596-601, 2016. DOI: 10.1038/ngeo2749[3] N. S. Steiner, W. G. Lee and J. R. Christian, "Enhanced gas uxes in small sea ice leads and cracks: Efects on CO2 exchange and ocean acidiccation", JGR Oceans, Vol. 118(3), 1195-1205, 2013. DOI: 10.1002/jgrc.20100[4] Ø. Seland, M. Bentsen, D. Olivié, T. Toniazzo, A. Gjermundsen, L. S. Graff, J. B. Debernard, A. K. Gupta, Y.-C. He, A. Kirkevåg, J. Schwinger, J. Tjiputra, K. S. Aas, I. Bethke, Y. Fan, J. Griesfeller, A. Grini, C. Guo, M. Ilicak, I. H. H. Karset, O. Landgren, J. Liakka, K. O. Moseid, A. Nummelin, C. Spensberger, H. Tang, Z. Zhang, C. Heinze, T. Iversen and M. Schulz, "Overview of the Norwegian Earth System Model (NorESM2) and key climate response of CMIP6 DECK, historical, and scenario simulations", Geoscientifc Model Development, Vol. 13(12), 6165-6200, 2020. DOI: 10.5194/gmd-13-6165-202
Developing the coupled climate model ACCESS-ESM1.5 for the early Eocene
Authors: Hutchinson David , Meissner Katrin , Menviel Laurie
Published: March 2024

We are currently developing the Australian community climate model ACCESS-ESM1.5 for deep time paleoclimate simulations. We are currently targeting the early Eocene (~55 Ma) and the Miocene climate optimum (~15 Ma); two warm intervals with high CO2 concentrations and strong polar amplification. The major challenge in adapting this model is to implement extensive changes to surface boundary conditions, including topography, vegetation, river runoff and ice sheets. The model has never previously been run outside of modern boundary conditions. We have developed new prototype simulations for each time period, and will present preliminary results for the Eocene and Miocene using ACCESS-ESM1.5. These simulations will be developed in parallel with simulations using the GFDL CM2.1 coupled climate model, which has been established as an efficient tool for reaching equilibrium paleoclimate scenarios. 
Pine root exudation increased under drought and even more under eCO2 and drought
Authors: Obersteiner Sophie , Oppenheimer - Shaanan Yaara , Klein Tamir
Published: March 2024

Tree processes belowground are highly complex and strongly affect the soil carbon. Trees assimilate carbon and allocate up to 20% of the carbon to the rhizosphere as root exudates. Rhizosphere processes in the forest soil might have a significant global effect. Abiotic factors such as intensified drought and elevated atmospheric CO2 (eCO2) will influence tree carbon fluxes as predicted under climate change. As trees play a vital role in maintaining Earth’s carbon balance, ecological studies on trees are crucial, especially in light of climate change.The effect of the predicted elevation of atmospheric CO2 and drought on the rhizosphere was studied on 2-years-old pine saplings in climate-controlled growth rooms. The results showed up to a twofold increase in assimilation, increasing shoot biomass, while root exudation rate remained unchanged in eCO2 compared to ambient CO2. Root exudation increased under drought, despite reduced assimilation. Under combined drought and eCO2 treatment, exudation rate increased even more by 56%, suggesting assimilated surplus carbon might have been stored in the roots under eCO2. In addition, we found an increase of soluble sugars in the stem under combined drought and eCO2 treatment, specifically glucose and fructose, indicating that indeed surplus carbon is stored during well-watered times under eCO2.Our results are unique because they show for the first time that pines were able to increase their root exudation under drought due to eCO2, potentially enhancing their resilience during drought recovery.
Assessing the potential of land use adaptation measures with eco-hydrological modelling to increase drought resilience.
Authors: Grantz Sven F. , Wagner Paul D. , Kiesel Jens , Fohrer Nicola
Published: March 2024

Droughts jeopardize both ecosystem services and economic productivity within river basins - especially as their frequency and intensity are expected to increase as a result of climate change. One aim of climate adaptation measures is therefore to increase resilience through water retention in landscapes. In this contribution we aim at identifying suitable land use adaptation measures to increase drought resilience. To this end, the eco-hydrological model SWAT+ is used to analyze the hydrological response of different land use classes under drought conditions in the Lippe catchment in Germany. The model represents catchment specific land use information on crops and crop rotations, tree species and imperviousness of urban and industrial areas. Anthropogenic effects such as water exchange with the Western German transportation canal network and tile drainages are also modeled. The model is calibrated specifically with regard to representing low flow periods based on available discharge measurements from several gauges. The hydrologic response of different land use classes shows variations in evapotranspiration, soil moisture, ground water recharge as well as surface runoff and lateral flow during a drought period. This illustrates the potential of land use changes to improve drought resilience, by promoting land uses that increase water retention. Based on these findings, further research will be conducted to investigate the potential of combined land use measures to increase resilience on the catchment scale and under different climate and adaptation scenarios. In the future, the modeling approach will serve as a planning tool for river basin management of the Lippe and the potential to transfer these measures to other catchment areas will be determined in the KliMaWerk research project funded by the German Federal Ministry of Education and Research as part of the "Water Extreme Events" (WaX) research programme.
The newly identified Middle Paleolithic technology in southwestern China 
Authors: Li Hao , Ruan Qijun , Peresani Marco , Dalpiano Davide , Chen Fahu
Published: March 2024

The Middle Paleolithic is a hotly debated issue in China, in particular with the intriguing findings in recent years in both northern and southern China. Here we present a new Middle Paleolithic site named the Longtan site located in the Heqing couty, Yunnan Province. The age of Longtan has been dated to ca. 60-40 ka. Lithic assemblage excavated from the site shows distinct technological and morphological features, with the Quina retouch being the most representative feature. Quantitative analyses have been done in order to reveal the technological characteristics of Quina scrapers. Results show that these scrapers were mainly made on thick and big-sized flake blanks and the functional edges exhibit scaled and invasive retouching scars. Resharpening flakes have also been identified, suggesting the existence of rejuvenation behavior and the lengthy use-life of Quina scrapers at Longtan. All these features are comparable with Quina scrapers found in the Middle Paleolithic sites in western Eurasia. The finding of Quina-type lithic assemblage at the Longtan site provides key evidence for our understanding of the diversity and complexity of the Middle Paleolithic techno-complexes in China.  
Inversion of real gravity data from geological faults using a generative neural network model
Authors: Rakoczi Henrietta , Barnes Gary , Prasad Abhinav , Toland Karl , Messenger Christopher , Hammond Giles
Published: March 2024

Normalising flows is a novel generative neural network model, which can be applied to Bayesian parameter inference. When gravity inversion is reformulated as a probabilistic inference problem, stable results can be obtained that naturally incorporate the inherent uncertainties and noise from the source background and the instrument. As opposed to some standard methods, Bayesian gravity inversion does not default to a single solution in an ill-posed problem, but informs the user about all possibilities that are consistent with the gravimetry survey of interest. It has been demonstrated that the normalising flow method can provide accurate results for a simulated data set, even when applied to high-dimensional data. Once the network is trained, the results can be obtained within seconds and it can be reused, without retraining, for multiple gravimetry surveys that are consistent with the training data set. Here, improvements on the previous work are presented, where the method is applied to a more realistic and complex geophysical problem; the inversion of gravity measurements to infer parameters of geophysical faults. The normalising flow network is trained and tested for fault models with various complexities, and finally the method is applied to the inversion of airborne gravimetry data.  