bluuebunny/crossref_metadata_2025 huggingface dataset:
Satellite mega-constellations and spacecraft re-entry: Are we harming Earth’s atmosphere?
Authors: Glassmeier Karl-Heinz , Schulz Leonard
Published: March 2024

Satellite mega-constellations are one of the main reasons for the current exponential growth of space flight. The increasingly large number of objects in orbit has already raised much concern about space debris and requires mitigation strategies. The common strategy for low Earth orbit (LEO) objects is to ensure their re-entry into Earth’s atmosphere, where they ablate and burn up, injecting material into the mesosphere and lower thermosphere. We discuss the significance of this anthropogenic injection compared to the natural one originating from meteoric sources, which provide a constant flow of cosmic dust and larger meteoroids into Earth’s atmosphere. Our comparison indicates that already in 2019 the anthropogenic mass injection has been significant (2.8%) compared to the natural injection. This number will rise in the future due to the ongoing implementation of satellite mega-constellations. More than 5,000 constellation satellites are in orbit right now with more than 100,000 proposed. Considering a worst-case scenario, the injection of metals could increase up to 90% and the aerosol injection up to 94% compared to the natural injection. As the material is mainly injected into mesosphere heights, possible influences on mesospheric and even stratospheric chemistry, with effects on the ozone layer, cloud formation or the climate are thinkable. Recent, first observations already confirmed the existence of spacecraft ablation remnants in stratospheric aerosol particles. This  emphasizes our theoretically conjectured significance of anthropogenic dust injection . However, further studies, including observations and modeling, are urgently required to further elucidate any atmospheric effects. Precautions need to be discussed now in order to protect our atmosphere from yet another human-made influence, that is space waste.
Exploring the Complexity of Climate Change with an Interactive and Collaborative Learning Tool: The "Climate Fresk"
Authors: Widmann Michel
Published: March 2024

The « Climate Fresk » is a french innovative educational tool designed to raise awareness about the challenges of climate change. Developed by the French organization CliMates in 2018, it engages students in an interactive and collaborative learning experience.This activity lasts around 3 hours and takes the form of a board game where students organized into groups of 4 to 7, working together to understand the complex dynamics of climate change. The game incorporates a set of 44 cards representing various factors related to climate change (e.g. greenhouse gas emissions, sea level rise, deforestation, ocean acidification, aerosol). The course is organized as follows:Step 1: The students’ goal is to place cards on the board, creating connections between different aspects of climate change. Behind the cards lay explanations about the item to help them solving some complex issues (e. is ice melting and sea level rise connected?).
Step 2: The students will be given some sheet and materials to stick the cards on it, draw the links and add additional decorations of their choice.
Step 3: The different Fresks are displayed on the classroom walls, and the group can present them, explaining their layout choices or items that particularly moved them.
Step 4: A discussion about the solutions is engaged
The primary objective of the Climate Fresk is to enhance participants' understanding of the causes and consequences of climate change while fostering discussions about possible solutions. By actively involving individuals in the learning process, this activity aims at empowering them with knowledge and inspire collective action.Teachers often find the Climate Fresk to be a valuable resource for education in high school settings. Additionaly to scientific knowledge, this approach encourages critical thinking, collaborative problem-solving but also creativity since the students will take some time to do a nice and efficent layout. The visual and interactive nature of the Climate Fresk makes it an effective tool for conveying complex scientific concepts in a simple and accessible educational tool. Moreover, it promotes active learning and brings a different learning experience based on creation of an mural fresco.Other similar works have been created since, such as the Plastic Fresk, the Soil Fresk, the Digital Fresk.
Literature review and empirical analysis of bend scour formulas.
Authors: Fructus Natacha , Leblois Solange , Piton Guillaume , Recking Alain , Evette André
Published: March 2024

Bank erosion is essential for the proper functioning of rivers and the preservation of their freedom space. However, when the assets are at risk, it is sometimes necessary to implement protective structures along the banks. Unlike civil engineering, soil and water bioengineering techniques offer the advantage of addressing various ecosystem services, thereby contributing to environmental preservation while protecting against erosion. Despite these advantages, the development of such techniques is hampered by a lack of understanding regarding their failure modes. Scour was identify as a factor of failure for 45% of cases of mechanical destruction on bioengineering structure. This is why accurate prediction of scour depths is a predominant factor for a successful design. In order to reduce the scope of the study, this work focuses on bend scour, where stresses on the outer bank are often significant. A review of existing literature was conducted to gain a deeper understanding of available methods for estimating this depth. Twelve empirical formulas for bend scour predication were identified and their domain of validity gathered. All these formulas were developed between 1930 and 2006 and some links between them were highlighted. Depending on the country in which they were developed, the news ones were often inspired from the old ones and used a part of the same dataset. Fifty natural bend were visited on ten lowland or piedmont rivers. Topographical and granulometric measurements were performed to compare the scour depths derived from literature formulas with field values. Some formulas appear to stand out due to their general tendency to overestimate depths or their precision under specific application conditions. Despite the limitations of the study, these results provide an initial overview of the trends for each formula, making it easier to understand the most appropriate conditions of application for each of them.
Evolution of large-scale landslide at Tuchang creek, Taiwan
Authors: Lo Chia-Ming , Wu Yu-Chen
Published: March 2024

The D077 study area is located on the right bank of Tuchang Creek in Wufeng Township, Hsinchu County, Taiwan. Two large-scale landslide events occurred in the D077 study area in 2004 and 2013, causing 14 casualties and disrupting traffic, seriously threatening downstream settlements. Until now, the rock slopes in the D077 study area are still in a state of toppling deformation and instability. In view of this, this study used multi-stage remote sensing, terrain analysis, geological survey, geophysical prospecting, drilling, and other data in the analysis of the evolution of large-scale landslides at D077 study area. The results show that the evolution of large-scale landslides (the D077 study area contains three sliding masses: S1, S2, and S3) can be divided into six periods: (1) the period of severe erosion of Tuchang creek and Chingchuan anticline, (2) rock mass decompression and toppling deformation period, (3) development of wedge failure trend of rock slopes at S1 sliding mass, (4) movement of S1 sliding mass and violent erosion of the S2 sliding mass slope toe, (5) toppling deformation develops rapidly at S2 sliding mass, (6) movement of S2 sliding mass and S3 sliding mass toppling deformation continues to develop. In the future, we predict that S2 and S3 will again cause debris sliding and large-scale rock mass sliding. This activity is also expected to threaten the safety of inhabitants and property in downstream of Tuchang creek.Key words: large-scale landslide, toppling deformation, remote sensing, geological survey, geophysical prospecting, drilling
Composition and diversity of reefal ostracod assemblages from the Zanzibar Archipelago (Tanzania): Proxies for paleoenvironmental reconstructions
Authors: Tian Skye Yunshu , Langer Martin R. , Yasuhara Moriaki , Wei Chih-Lin
Published: March 2024

The tremendous biodiversity of tropical reef ecosystems fascinates ecologists and evolutionary biologists alike, yet it is threatened by increasing natural and anthropogenic disturbances worldwide. Meiobenthic biotas on coral reefs, especially ostracods, are poorly understood in terms of their diversity and compositional patterns. This study represents the first large-scale assessment of shallow-marine ostracods from three islands of the Zanzibar Archipelago (Zanzibar, Pemba, Mafia, Tanzania), where the reef ecosystem is highly diverse and productive. We characterized four ecologically distinct ostracod faunas each associated with different benthic habitats, that were deep fore reefs, shallow fringing reefs, degraded fringing reefs and intertidal algae. We identified typical ostracod taxa that showed affinities to hard corals or algae on the reef platforms, respectively. We concluded that water depth and habitat type are likely the most important environmental factors determining the diversity and faunal structure of reefal ostracod assemblages in the tropical, shallow-marine setting. Highest diversity was found on shallow fringing reefs where reefal and algal taxa exhibited maximum overlap of their distributional ranges, while the sand flats, mangrove and marginal reefs within the intertidal zone had much lower diversity with high dominance of euryhaline taxa. Furthermore, the detriment of human activities to overall reef health is evident as shown by the diversity loss and compositional changes of ostracod faunas near Zanzibar Town, where the coastal development has been the most intense during past decades. This study therefore highlights the ecological significance of reefal ostracods and indicates the usefulness of ostracods as a model proxy for environmental assessment. 
Increases in Poisson’s ratio due to cyclic deformation in cracked rock
Authors: Healy David
Published: March 2024

Quantifying the changes in elastic properties of rocks during deformation is an important task. Effective Medium Theory (EMT), as formulated by Sayers & Kachanov (1995) relates the crack fabric (or damage) to the elastic properties. EMT has been successfully applied in the forward sense to predict the evolution of elasticity and related acoustic velocities in response to prescribed changes in crack density; and in the inverse sense to recover crack densities from laboratory measurements of acoustic velocities.  However, EMT fails to predict an important observation from laboratory studies of rock deformation: cyclic loading under uniaxial and conventional triaxial loads of rock samples can produce significant increases in Poisson’s ratio. These increases correlate with increasing number of cycles and with increasing crack density. This phenomenon has been known since the work of Walsh (1965), Brace et al. (1966) and Zoback & Byerlee (1975). More recent work by Heap & Faulkner (2008) and Heap et al. (2009; 2010) has extended the findings across a range of different lithologies.Published EMT equations predict Poisson’s ratios that stay constant or decrease with increasing crack density. Resolving this discrepancy is important because Poisson’s ratio may play a key role in producing stress rotations in the damage zones of faults, thereby making them ‘weak’ and prone to slip even when the normal stress is high e.g. the San Andreas Fault (Faulkner et al., 2006; Healy, 2008). Building on the work of David et al. (2012 & 2020) incorporating the effects of crack closure, sliding on cracks (Kachanov, 1992) and grain boundaries (Sayers, 2018) during loading, and delayed back-sliding during unloading, closed form micromechanical equations have been derived to describe increases of Poisson’s ratio with increasing number of cycles. Critically, increases in Poisson’s ratio are predicted even without including the effects of new cracks. Examples are shown comparing the predicted changes in Poisson’s ratio using the newly derived equations to data from uniaxial and triaxial laboratory tests on cracked rocks.
High-resolution climate model data over EURO-CORDEX with a focus on cities
Authors: Top Sara , Caluwaerts Steven , De Cruz Lesley , Hamdi Rafiq
Published: March 2024

To investigate the effect of climate change on cities and climate adaptation strategies in cities, high-resolution climate model data is needed to resolve urban-rural and intra-urban processes. Due to computational limits, it is currently impossible to create long-term (sub-)kilometric simulations over extended regional domains, such as the EURO-CORDEX domain (Jacob et al., 2020). However, short-term climate simulations at 2.5 km horizontal resolution were performed over Europe with the atmospheric model ALARO which was coupled to the land surface model SURFEX. The model output has been validated against conventional datasets and non-traditional measurements such as those of urban meteorological networks (Caluwaerts et al., 2021). Including non-traditional meteorological measurements is important to verify whether the model captures the urban signature well. Further, a methodology will be presented to obtain climate projections with a more detailed spatial resolution over several European cities. The added value of this new avenue using machine learning to emulate the climatological characteristics from a limited set of cities and generalise this to other cities in the EURO-CORDEX domain will be investigated. Caluwaerts, S., Top, S., Vergauwen, T., Wauters, G., De Ridder, K., Hamdi, R., Mesuere, B., Van Schaeybroeck, B., Wouters, H. and Termonia, P., 2021. Engaging schools to explore meteorological observational gaps. Bulletin of the American Meteorological Society, 102(6), pp.E1126-E1132.Jacob, D., Teichmann, C., Sobolowski, S., Katragkou, E., Anders, I., Belda, M., Benestad, R., Boberg, F., Buonomo, E., Cardoso, R.M. and Casanueva, A., 2020. Regional climate downscaling over Europe: perspectives from the EURO-CORDEX community. Regional environmental change, 20, pp.1-20.
Seismic Attenuation Imaging in the Western Part of the North Anatolian Fault Zone
Authors: Zhu Wei-Mou , De Siena Luca , Zhao Lian-Feng , G. Cornwell David , Xie Xiao-Bi , Gabrielli Simona , Abbas Aqeel , He Xi , Zhang Lei , Sketsiou Panayiota , Lamest Stella , Yao Zhen-Xing
Published: March 2024

Colossal and devastating earthquakes are typically associated with the slip and rupture of fault zones. Fault zone imaging is challenging yet crucial to understand fault structure and behavior, and consequently hazard assessment and mitigation. Seismic attenuation imaging provides constraints on the fault zone structure that are independent of seismic velocity imaging. Here, we image the S-wave total attenuation (Qs) structure of the western part of the North Anatolian Fault Zone (NAFZ) using data recorded by the DANA (Dense Array for North Anatolia) array. The area of interest is divided into three distinct regions by the northern and southern segments of the NAFZ, which extends from north to south: the Istanbul Zone to the north, the Armutlu Block in between, and the Sakarya Terrane to the south, respectively. The Armutlu Block exhibits much higher attenuation compared to the other two regions. The anomaly body has an attention value of 0.0008 with a notable 3D distribution pattern: It extends from 30.2°E to 30.6°E and around roughly 40.6°N following the northern strand of the NAF and shows a west-east trend, dipping deeper into the crust to the east from depths of 5 to 15 km. Combining previous geological, geodetic, micro-seismicity, and other geophysical observations, we inferred that the high values are a sign of fluid pathways. Micro-seismicity and strain distributions around the Armutlu Block are in line with the assumption fluids migrate through cracks and increased permeability attributed to the background stress, particularly residual stress after the 1999 M7.4 Izmit earthquake and M7.2 Düzce earthquake.This research is supported by the National Natural Science Foundation of China (U2139206, 41974061, 41974054) and the Special Fund of China Seismic Experimental Site (2019CSES0103). The first author has also been financially supported by the China Scholarship Council (202204910302).
Dykes and their magma overpressure
Authors: Mondal Tridib Kumar , Biswas Sirshendu Kumar
Published: March 2024

Dykes are essentially magma filled fractures within the earth’s crust often formed by the pressure imparted by the intruding magma. Magnitude of the magma overpressure has been traditionally determined utilizing elastic properties of the host rock and the complete dimension i.e., full length and maximum width of the fractures. Full exposures of dykes (from tip to tip) are rare, however, as most of the dyke bodies encountered in the field are subject to erosion or disruption along its length as a result of geological time, making estimation of aspect ratios challenging.We propose a new method of estimating total length and maximum width of dykes from their partial outcrops featuring at least one exposed tip. Taking into account the fact that majority of dykes form as dominantly opening mode fractures with an elliptical shape of opening, the method involves solving the equation of this ellipse using every conceivable combination of a pair of ground points recorded on the dyke margin considering the visible tip as the origin. Validity of the method has been checked using published data obtained from incomplete dyke outcrops exposed in the caldera walls of Miyake-jima volcano in Japan. The calculated estimates are in line with the results acquired through a previous published method. The present method has been effectively utilized to calculate the aspect ratios of partially exposed mafic dykes emplaced within the younger granite of the Chitradurga Schist Belt in the western Dharwar craton of peninsular India. We discuss the ranges of their magma overpressure and depths of origin as well as the stress intensity factors associated with the host granite. 
Characterizing deep fracture zones within the natural barrier: Insights from borehole data around the KAERI underground research tunnel
Authors: Choi Ji-Min , Jung Soolim , Jeong Doohee , Kim Nak Kyu , Park Kyung-Woo , Kim Young-Seog
Published: March 2024

High-level radioactive waste repositories rely on multi-barrier systems, including natural and engineered barriers, crucial for long-term safety through isolation and delay functions. Improving the performance of natural barriers poses challenges, necessitating thorough evaluation via ongoing field surveys and lab tests. Natural barriers are categorized and analyzed based on lithological and structural characteristics. Structural elements such as fractures, joints, and faults play a crucial role in performance assessment as they can serve as pathways for groundwater flow. Existing studies lack a unified criterion for defining structural boundaries, prompting a systematic review to establish standards suitable for site characteristics by applying various structural factors to study area boreholes. Considering the deep location of the disposal site, borehole data plays a pivotal role. The KAERI Underground Research Tunnel (KURT) is a small-scale Underground Research Laboratory (URL) with a maximum depth of 120 m excavated within the Korea Atomic Energy Research Institute (KAERI). The boreholes used in the study were drilled to depths ranging from approximately 500 to 1,000 m within the site, including KURT. The preliminary fracture zone was identified through frequency analysis of gaps between fractures in the borehole images. As reviewed previously, the methods for defining the fracture zone can broadly emphasize the background fracture and presenting exclusion conditions or emphasize the dense area of fractures and presenting boundary conditions. For each method, the match rate with the preliminary fracture zone was validated. To confirm the correlation between the match rate and the natural state, it was compared with the actual fracture density found in the drill core. By integrating a series of processes, we could quantify standards for defining deep fracture zones using boreholes. The results of this study will contribute to a three-dimensional model of the deep brittle structure within the natural barriers. Future research can explore the identified fracture zone, surface fracture zone, and the definition of fault zones with fault rocks.Keywords: Deep fracture zones, background fracture, brittle structure, Borehole data, KURTAcknowledgements: This research was supported by the Institute for Korea Spent Nuclear Fuel (iKSNF) and National Research Foundation of Korea (NRF) grant funded by the Ministry of Science and ICT (MSIT) (2021M2E1A1085200).
Using the SWAP model for the stochastic analysis of hydraulic parameter uncertainty propagation in soil water balance components
Authors: de Jong van Lier Quirijn
Published: March 2024

The SWAP model employs a finite difference numerical solution of the Richards equation, including root water uptake, to simulate the movement and predict the state of soil water and associated quantities in the vadose zone. The relation between hydraulic conductivity K, pressure head h, and water content θ can be described by parameters of the Van Genuchten-Mualem (VGM) relations, where the quality of these parameters determines the quality of the model output. We developed a stochastic procedure to evaluate the outputs of the SWAP model according to the uncertainty and correlations in the VGM parameters. Specific software was developed to (1) fit VGM parameters to observed retention and conductivity data to obtain values, standard errors, and correlations of transformed parameters (software HPFit); (2) generate p stochastic realizations of the VGM parameters using Cholesky decomposition (software StochHyProp), and (3) run the SWAP model with each of the p parameter realizations for specific scenarios, extracting simulation results (software RunSWAP), e.g., the simulated water balance components evaporation, transpiration, bottom flux, and runoff. The results from the last step yield the respective frequency distributions of the output values. Examples will show that the most commonly performed prediction using the average VGM parameter values does not always agree with the median of the stochastic realizations. The developed procedure allows the quantitative analysis of the uncertainty of SWAP model output, adding to the interpretation of the predictive power of hydrological models like SWAP.
Characteristics of salinity-controlled submesoscale fronts in the Bay of Bengal and their impact on the upper ocean
Authors: Duan Wei , Cheng Xuhua , Zhou Yifei , Gula Jonathan
Published: March 2024

This study investigates the characteristics of salinity-controlled submesoscale fronts in the Bay of Bengal (BoB), based on a high resolution model output (MITgcm LLC4320). Large horizontal gradients of temperature, salinity, and density are found in the northern bay, with salinity and density gradients being notably more pronounced than those of temperature. Density fronts in this region are controlled by salinity rather than temperature due to the amount of freshwater input. Salinity fronts are most often compensated by temperature in the upper ocean of the BoB, especially at small scales. Fronts are classified into 4 types based on the value of the Turner angle. Among them, the salinity-controlled fronts compensated by temperature play a leading role in the northern BoB from October to March, while salinity-controlled fronts reinforced by temperature become equally numerous during the rest of the year. Heat fluxes significantly affect the temporal variations of temperature compensated versus reinforced fronts, while freshwater fluxes only play a minor role. When compensated fronts get arrested, warm water sinks beneath the cool water, favoring the formation of a temperature inversion layer and a barrier layer.
Electromagnetic response to undersea earthquakes in marine layered model
Authors: Cheng Qianli , Gao Yongxin
Published: March 2024

In this study, we adopt a horizontally layered model which consisting of air, seawater and undersea porous rock and develop an analytically-based method to calculate the seismic and EM fields generated by undersea earthquakes. We conduct numerical simulations to investigate the characteristics of the EM response in three case (the receivers located at the seafloor, in the seawater near the sea surface and in the air, respectively). The results show that two kinds of EM signals can be identified in the EM records at these receivers. The first is the early EM wave arriving before the seismic waves and the second is the coseismic EM fields with apparent speed of the seismic waves. The EM signals observed at the seafloor are mostly stronger than those observed in the seawater and air near the sea surface. We applied this method to simulating the EM response to the 2022 Mw 7.3 earthquake that took place in the sea near Fukushima, Japan. At the receiver with 80 km epicentral distance at the seafloor, the predicted coseismic electric and magnetic signals reach the amplitudes of 2 μV/m and 2 nT, respectively. The results suggest a possibility to monitor the EM disturbances associated with marine earthquakes and use them to serve the earthquake early warning or earthquake mitigation.
Can beavers clean our streams? A study from three agricultural catchments in south-west England
Authors: Bradbury Gareth , Puttock Alan , Coxon Gemma , Clarke Stewart , Brazier Rich
Published: March 2024

In common with many European streams, most streams in south-west England have failed to reach Good Ecological Status under the Water Framework Directive. The landscape comprises mainly pastoral and arable fields, from which rainwater can run off, carrying huge quantities of sediment and surplus fertiliser. The receiving streams, often highly modified through channelisation, are degraded from the physical, chemical and biological effects of these pollutant loads, most notably high nutrient and fine sediment inputs leading to eutrophication. After an absence of 400 years, Eurasian beavers Castor fiber are now being re-introduced into some of these landscapes, or are colonising naturally from nearby introductions. Through the building of their dams and creation of diverse, ponded wetland environments, beavers have been shown to deliver multiple ecosystem services, including flow moderation, habitat provision and water quality improvements. Encompassing highly productive, vegetation-rich shallow areas and deeper, oxygen-limited areas with different nutrient-cycling pathways, beaver wetlands have the potential to improve water quality through the settling out of solids and uptake and cycling of nutrients. By contrast there are periodic releases of solids and nutrients due to burrow and canal excavations, dam breaches and nutrient inputs from the beavers themselves and the diverse fauna and flora supported in their wetlands. To examine the potentially dynamic effects of beavers on the transfer of sediments and contaminants (nutrients) in catchments, this study used fortnightly water sampling at the inflow, outflow and upstream and downstream of three beaver re-introduction enclosures over two years. In addition, automated samplers were deployed to investigate finer temporal resolution responses to rainfall events. For each site, suspended solids, nitrogen, carbon and phosphorus concentrations and loads were determined. Sediment storage dynamics were revealed through the novel use of sonar monitoring in ponds and continuous in-situ turbidity sensor measurements at the inflow and outflow. Results demonstrate the dynamic nature of sediment and nutrient reduction in beaver-engineered wetlands, with switches between source and sink states depending on inflow conditions and pond-specific factors. Beaver wetlands were shown to remove nutrient pollution where inflow loads were high and the mixed temporal and spatial dimensions of this study help resolve differences in results between previously published studies.
Spatial Variability in Meander Characteristics Within Modern Distributive Fluvial Systems (DFS)
Authors: Kerr Heather , Owen Amanda , Quick Laura , Williams Richard , Hartley Adrian , Eizenhoefer Paul
Published: March 2024

Fluvial systems support a large variety of habitats, are important biogeochemical interfaces and act as conduits for delivering sediment and water to seas and oceans, as well as forming political boundaries. Fluvial sandstone deposits have the potential to act as reservoirs for carbon capture and storage and form the basis of geothermal and freshwater aquifers. Therefore, understanding the lithological variation of such deposits is critical to enhancing natural resource exploration and the sequestration of carbon from our atmosphere, in addition to providing insight into modern fluvial geomorphic processes.Recent research suggests that the abundance of subsurface fluvial deposits, such as meander deposits, have been significantly under-estimated within sedimentary basins. Therefore, meander deposits may form a bigger proportion of the rock record than previously thought. Research is required to better understand the spatial variation in gross-scale meander system characteristics, such as meander size and deposit architecture.This project aims to bridge these knowledge gaps by studying both modern and ancient meander deposits within a spatial context, by exploring how meander characteristics vary within and across two sedimentary basin types within different climatic settings. This will provide new quantification of the spatial variability expected within subsurface deposits and provide further understanding of fluvial geomorphic processes within sedimentary basins. The Meander Statistics Toolbox (MStaT - Ruben et al., 2021) was used alongside GIS and Google Earth Engine (GEE) to extract a range of meander characteristics (e.g. meander sinuosity, amplitude and migration rate) from modern DFS. Results from the Wood River DFS, Alaska, indicate that meander characteristics vary spatially, however not all characteristics follow a distinct downstream trend. The active channel width of the DFS is found to decrease downstream as expected based on literature (e.g. Nichols and Fisher, 2007; Weissman et al., 2010), however the channel belt width shows no clear downstream trend. Characteristics such as meander sinuosity and amplitudes are found to increase downstream to the medial zone of the DFS, and decrease towards the distal region. Meander migration rates follow a decreasing downstream trend from proximal to distal regions of the DFS. Comparison with the Bermejo DFS, Argentina will indicate how these compare to a different geographical and basin setting.The implications of this research are as follows: 1) to further understand modern fluvial geomorphic processes; 2) to provide new quantification for the variability expected within subsurface deposits and 3) to enhance understanding of the lithological variation of deposits for natural resource exploration and carbon sequestration.
Comprehensive analysis and risk assessment of tailings storage facilities in China 
Authors: Su Chenxu , Rana Nahyan M. , Evans Stephen G. , Wang Bijiao , Zhang Shuai
Published: March 2024

The historical failures of Tailings Storage Facilities (TSFs) in China have led to severe downstream consequences, encompassing loss of life, economic damage, and environmental contamination. Despite these consequences, the comprehensive documentation and quantitative evaluation of TSFs in China have been notably lacking. The existing records of TSFs are incomplete, and there is a deficiency in accurately assessing the frequency of their failures. This gap in knowledge has been a significant obstacle in effectively assessing and mitigating risks associated with TSFs. Our research involved compiling and analyzing new databases, shedding light on the historical failures and current status of TSFs in China. We uncovered 143 TSF failure incidents between 1957 and 2022. This figure largely exceeds the approximately 20 failures reported in earlier studies, highlighting a critical underestimation in past assessments. The human and economic damage of these incidents has been considerable, with 840 lives lost, 1,416 houses damaged, and 28,923 individuals adversely affected. Furthermore, the total volume of tailings released in these failures surpassed 12.7 million m3. A notable observation from our study is that about 75% of these failures involved tailings flowing into water bodies, exacerbating environmental pollution significantly. Our study also presents an in-depth statistical analysis of the magnitude and frequency of these failures. We found that the average return period for TSF failures in China, resulting in at least 10 fatalities, is approximately every five years. For failures with released volumes exceeding 1 million m3, the average return period extends to about 16 years. In addition to historical data, we include a comprehensive review of current TSFs. Our review confirms that there are 14,217 existing TSFs in China alone, leading to an estimated cumulative failure rate of approximately 1%. Our work further includes the development of a supplementary database encompassing 1,853 TSFs, providing essential statistics such as storage volume and dam height. This database is a crucial tool for ongoing and future risk assessments. Applying our database-driven, regionally-simplified risk assessment approach, we conducted a case study in Jilin Province. The results are concerning, indicating 11 TSFs bearing intolerable risks, among which the most hazardous TSF presents a potential loss of life estimated at 175 individuals. Our study offers the most comprehensive overview of TSF failures and their implications in China to date. The extensive scope of this research bears substantial implications for prospective nationwide utilization, particularly in the enhancement of risk assessment methodologies and the enforcement of efficacious mitigation measures for TSFs in China.
Hybrid simulations of multiple reflection of protons and heavy ions at Earth’s bow shock
Authors: Gingell Imogen , Madanian Hadi
Published: March 2024

Ion reflection is known to be a key component of particle energisation and heating in super-critical collisionless shockwaves. As a source of free energy, reflected ions drive stream instabilities in the shock foot, create magnetic perturbations, and contribute to magnetic field amplification in the upstream and downstream regions of quasi-perpendicular shocks. Where ions reflect from the shock ramp multiple times, a longer dwell time in the shock foot allows for more opportunities for interaction with non-stationary and turbulent shock processes, which can result in injection into processes such as diffusive shock acceleration and shock drift acceleration. To characterise the pathway to multiple ion reflection, we perform a series of 2D and 3D hybrid particle-in-cell simulations (fluid electron, particle ions) over a parameter range typical of Earth’s bow shock, varying Mach number, plasmas betas, and the angle between the shock normal and upstream magnetic field (θBn). This enables a parametric investigation of the density fraction of multiply reflected ions both upstream and downstream of the shock, for protons and for heavier ion components of the solar wind such as He2+. We discuss methods for identification of multiply-reflected ions in kinetic plasma simulations, corresponding analogues for observations (where available), and investigate their impact on shock energetics. By examining the partial moments of reflected ions in two- and three-dimensional simulations, we also explore which shock processes drive multiple reflection.
Geologic Mapping for the AMADEE24 analog mission to Mars simulated in Armenia.
Authors: Frigeri Alessandro , Özdemir-Fritz Seda , Groemer Gernot ,   the RSS AMADEE24 Team
Published: March 2024

Cartographic mapping has always been a key to exploration, starting from exploring planet Earth.  Since the dawn of the Apollo program, geologic mapping has been critical to all the phases of the mission.   The choice of the landing site depended on interpretations made on the orbital data base maps.   The planning of Extra Vehicular Activities (EVAs) required information on the expected terrain, including life-threatening hazards. The mission-specific geological maps served to place observations collected during the operation.  Finally, the geologic maps evolved after the mission, with the new knowledge acquired in-situ.  Within the AMADEE24 mission to Armenia, we introduced geologic mapping to support the mission operation and the science made by the single experiments.  The pre-mission mapping will be based on remote sensing data.  Syn-mission mapping will introduce large-scale mapping around the region of interest where the human and robotic missions will operate.  Finally, we will work on the post-mission geologic mapping, which will synthesize scientific observations useful to understand better the nature of the materials and the sequence of the geologic processes of the AMADEE24 landing site.Our work will present the activity done so far, especially the pre and syn-mission mapping done during the mission planned for Mars 2024. 
Amphibole origin in the mantle lithosphere peridotites beneath continents: An example from Marais de Limagne (Massif Central, France) xenoliths
Authors: Puziewicz Jacek , Aulbach Sonja , Ntaflos Theodoros , Matusiak-Małek Magdalena
Published: March 2024

The Marais de Limagne (MdL) site is located at the Devès volcanic field in the French Massif Central. MdL is known for abundant peridotite xenoliths, which come from the “southern domain” of lithospheric mantle underlying Variscan crust of the Massif Central. The MdL xenolith suite consists of spinel lherzolites and harzburgites which contain from 0 to 21 vol. % of amphibole (Touron et al. 2008). We studied in detail 13 xenoliths in order to understand better the mechanisms of amphibole formation by modal metasomatism.The suite studied by us contains from 0 to ca. 20 vol. % of amphibole, the textural context and volume of which varies from thin rims of the mineral on spinel to rocks containing thick mantles of amphibole on subordinate or relict spinel. Exceptionally (one xenolith), amphibole occurs as interstitial grains independent of spinel. Amphibole is pargasite sensu IMA 2012 classification. Peridotites consist of olivine Fo 89.4-90.5, orthopyroxene Al 0.11-0.19 atoms per formula unit (apfu), clinopyroxene Al 0.13-0.28 apfu and spinel Cr# 0.09-0.39. The exception is harzburgite with olivine Fo 87.0 (orthopyroxene Al 0.11, clinopyroxene Al 0.15 apfu, spinel Cr# 0.15). Clinopyroxene REE patterns vary from LREE-depleted to LREE-enriched. The abundance of amphibole in many xenoliths and equal participation of peridotites with LREE-depleted and LREE-enriched clinopyroxene distinguishes the MdL suite from other xenolith suites from the Devès volcanic field, dominated by lherzolites which contain no or only traces of amphibole and mostly contain aluminous clinopyroxene with LREE-depleted REE patterns.Clinopyroxene occurring in rocks containing no or little amphibole has < 100 ppm of Sr, whereas that coexisting with abundant amphibole has 230-370 ppm of Sr. The content of Ba in amphibole varies from 2.6 ppm in rocks with only thin rims of mineral on spinel to 467.0 ppm in those which contain high volumes of amphibole. The REE patterns of amphibole are similar to those of coexisting clinopyroxene. Because both Sr and Ba are fluid-mobile elements, we assume that amphibole has originated by reaction of hydrous fluid with spinel, in which clinopyroxene has also participated as a source of elements not present in a fluid or spinel. By analogy with a similar mechanism described by Puziewicz et al. (2023), we speculate that hydrous fluid migration through the peridotite host might have induced its recrystallization.Puziewicz et al. 2023, Journal of Petrology 64: https://doi.org./10.1093/petrology/egad049Touron et al. (2008), In: Metasomatism in Oceanic and Continental Lithospheric Mantle, Geological Society Special Publ. 293, 177-196.
Three-dimensional crustal velocity structure of the north-eastern Gulf of Aden continental margin
Authors: Chen Jie , Leroy Sylvie , Watremez Louise , Robinson Adam
Published: March 2024

Continental rifting is the Earth’s fundamental tectonic process that may result in a new plate boundary, i.e., mid-ocean ridges, with the accretion of new oceanic crust. At present, continental rifted margins are classified into two end-members based on the amount of magmatism that occurred during the rifting process: magma-rich and magma-poor. However, various factors influence the formation of these margins, such as the inheritance of segmentation, extension obliquity, syn-rift magmatism, and sedimentation. The Gulf of Aden represents a good example for understanding such spatial variations in the formation of rifted margins. It consists of an oblique rifting system, with young and segmented margins (34-17.6 Ma) and thin sediments. In addition, the Gulf of Aden exhibits magma-rich margins in the west, related to the Afar hotpot, and magma-poor margins in the east, with a possible zone of exhumed continental mantle.In this study, we develop a 3-D P-wave velocity model across the north-eastern Gulf of Aden continental margin, using wide-angle seismic refraction data from a combined onshore-offshore survey with 35 ocean-bottom seismometers and 13 land seismometers. Approximately 187,000 P-wave first arrivals were picked and inverted in 3-D, with the modelling informed by constraints from previously published 2-D velocity models. Here, we present our preliminary tomographic results that illustrate the spatial variations in the crustal velocity structure of the continent, continent-to-ocean transition (COT), and oceanic domains, as well as the comparison between our 3-D and the published 2-D velocity structures of the north-eastern Gulf of Aden continental margin.
Different Wilson Cycle styles in Western Europe: the key role of inheritance
Authors: Chenin Pauline , Manatschal Gianreto , Frasca Gianluca , Lescoutre Rodolphe , Masini Emmanuel
Published: March 2024

In the classical Wilson Cycle concept, orogeny is assumed to follow protracted subduction of a wide oceanic domain. Such subduction systems form magmatic arcs associated with high-temperature and low-pressure metamorphism in the subduction upper plate, and depletion of the mantle wedge above the slab. Since its emergence, the Wilson Cycle concept has been largely used to study collisional orogens in general, and yet, in Western Europe, the Pyrenees and the Alps are both devoid of magmatic arc remnants.Recent field studies and paleogeographic restorations suggest that both the Pyrenees and the Alps resulted from the closure of narrow proto-oceanic domains that may have never reached the stage of steady-state seafloor spreading. This would imply that rift systems may be inverted at any stage of their development, including prior to the onset of steady-state seafloor spreading. Inversion of such a rift system would not form a magmatic arc due to the limited length of the slab, and hence orogeny would essentially be a mechanical process mainly controlled by the inherited rift architecture.In this presentation, we first describe the paleogeographic settings of the Alpine Tethys–Pyrenean rift systems. We show the results of an innovative kinematic reconstruction approach that integrates field observations, realistic margin widths and pre-rift tight full fit restorations.Second, we discuss how the margins along-dip architecture has controlled the two-dimensional architecture of the Pyrenean and Alpine orogens. We show that the major escarpments inherited from rifting and separating the thick-crusted and buoyant proximal domain from the thin-crusted and denser distal domain have become first-order ramp structures that today separate the external- from the internal part of both orogens.Finally, we explore how the along-strike segmentation of the Pyrenean and Alpine rift systems have controlled the three-dimensional architecture of the subsequent orogens. We show that the segmentation of the Pyrenean and Alpine rift systems, which both used to display ribbons of thick continental crust between overstepping rift basins, can explain most of the non-cylindricity observed today in both the Pyrenean and Alpine orogens.
Differential migration of immiscible liquids in gabbroic crystal mush: the Skaergaard Intrusion, East Greenland
Authors: Holness Marian , Nielsen Troels , Namur Olivier
Published: March 2024

Ferro-basaltic liquids intersect a binode during fractionation, splitting into two immiscible silicate liquids, one Si-rich and the other Fe-rich. The two liquids have very different physical properties: the Si-rich liquid is more buoyant and viscous, preferentially wetting plagioclase, whereas the Fe-rich liquid preferentially wets grains of mafic minerals and Fe-Ti oxides. The density difference means that when a crystal-poor magma body intersects the binode, it is likely to undergo compositional stratification, with implications for the compositions of any eruptions. When the interstitial liquid in a crystal mush unmixes, the density difference is compounded by the differences in wetting properties, leading to complex behaviour if capillary forces act in a different direction to that of gravity. The extent and scale of differential migration of unmixed liquids may thus play an important role in the genesis of the Daly Gap, while the preferential partitioning of P, PGE and REE into the Fe-rich conjugate has significant implications for formation of economically important deposits.The Skaergaard Intrusion of East Greenland records abundant evidence for differential migration of immiscible silicate liquid conjugates. At the intrusion scale, the roof rocks are more silica-rich than the cumulates at the floor, consistent with intersection of the binode by the bulk magma leading to the accumulation of the buoyant Si-rich conjugate in the roof mush. This is supported by the localised presence of reverse modal layering on the floor, interpreted as bodies of dense Fe-rich liquid ponded at the top of thin (
Groundwater effects on flood dynamics 
Authors: Berghuijs Wouter , Slater Louise , Woods Ross , Hrachowitz Markus
Published: March 2024

Fluvial floods are typically the result of large precipitation or snowmelt events, often conditioned by high pre-event soil moisture levels. However, soil moisture represents only a small fraction of the water stored in landscapes. Groundwater, often a much larger water store, may also contribute a significant proportion of river flow but its role in large-scale flood assessments often remains understudied. Here I discuss how (ground)water storage conditions can shape multi-year variability and long-term trends of river flow and flooding across thousands of catchments worldwide. Since often relatively slow groundwater dynamics can affect the much faster and more erratic flood responses, incorporating groundwater may be important to accurately model and analyze these hydrological extremes.