bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards seismic monitoring of terrestial ecosystems: an exploratory data analysis of the SeisSavanna dataset
Authors: Steinmann Rene , Nissen-Meyer Tarje , Cotton Fabrice , Tilmann Frederik , Mortimer Beth
Published: March 2024

Our planet experiences ongoing unrest across various scales, from human footsteps to the powerful forces of volcanic eruptions and megathrust earthquakes. Seismic sensors, typically employed for geophysical studies, record diverse phenomena, including ground vibrations caused by the movement of terrestrial animals, known as footfall signals. The recently released SeisSavanna dataset comprises approximately 70,637 footfall signals from 11 different species in the African savanna. Consequently, ground-based vibrations might represent an underexplored sensory mode for continuously monitoring habitat usage and undisturbed animal behavior. To gain a deeper understanding of footfall signals, we conduct exploratory data analysis on the SeisSavanna dataset. Utilizing a scattering transform, we capture the distinctive features of footfall signals, creating a high-level and interpretable data representation for subsequent analyses. Seismogram atlases and clustering enable us to group similar types of footfall signals and investigate the signal-altering path and site effects, providing a comprehensive overview of the entire dataset. Moreover, this data-driven approach serves as a quality check for the species labels retrieved from co-located camera traps with a limited angle of view.
Climate change, disturbance legacy and abrupt shifts in ecosystem functioning: what makes arid African savannas more resilient?
Authors: Vermeulen Liezl Mari , Verbist Bruno , Van Meerbeek Koenraad , Slingsby Jasper , Negri Bernardino Paulo , Somers Ben
Published: March 2024

The accelerating pace of climate change has led to unprecedented shifts in surface temperature and precipitation patterns worldwide. Regions particularly susceptible to these changes include African savannas. With increased climate anomalies and human impacts, comes increased disturbance events in the form of fires, overgrazing from elephants, invasive species etc. Consequently, there is a continual, large-scale transformation in vegetation patterns. Long-term ecosystem characteristics, such as soil traits, topography, and species composition, also contribute to the susceptibility of ecosystems to these climate and disturbance pressures. Understanding the complex interaction between climatic pressures, local disturbance drivers and underlying ecosystem traits, and their impact on ecosystem functioning and stability, is thus crucial.This research pursued a dual objective: firstly, detecting shifts in ecosystem functioning within the African savanna biome and analysing their spatial and temporal patterns; secondly, exploring the interplay between climate legacy, disturbance legacy, and underlying ecosystem characteristics, and how these factors influence savanna ecosystem resilience at regional and local scales in the context of global change. Remote sensing time series analysis and breakpoint detection algorithms were employed to identify change hotspots in the South African savanna biome. Combining this ethodwith survival analysis, a novel approach, also helped uncover large-scale climatic drivers and underlying ecosystem traits facilitating these changes. Bayesian hierarchical modeling, coupled with field data collected in the Kruger National Park of South Africa, was then utilised to delve into the complex interactions between disturbance legacy (e.g., drought legacy, history of extreme rainfall events, increased fire frequency, and elephant activity) and the resistance and resilience of the savanna landscape at a local scale. The outcomes of this research contribute to prioritising conservation efforts and enhancing our understanding of the future of savannas in the face of global change.
Statistical Modelling of Permafrost Subsidence Based on High-resolution InSAR Data
Authors: Liu Zhijun , Widhalm Barbara , Bartsch Annett , Kleinen Thomas , Brovkin Victor
Published: March 2024

The northern high latitudes are warming much faster than the rest of the planet. While gradual thaw of permafrost is accounted for in the recent generation of the Earth System Models (ESMs), consequences of the abrupt thaw of permafrost and the subsequent greenhouse gas release are not yet taken into consideration. However, an abrupt thaw of very small fraction of the northern permafrost region can lead to significant carbon release and subsequent global warming (Turetsky et al. 2020).An in-depth analysis of fine-scale permafrost subsidence processes is crucial for improved representation of abrupt thawing in simulations. Currently, permafrost subsidence is only taken into consideration in a few models, where subsidence is described in a deterministic process-based approach. This approach overlooks the high spatial heterogeneity in fine-scale permafrost processes.Recent advancements in satellite technology allow the acquisition of Interferometric Synthetic Aperture Radar (InSAR) data on permafrost vertical displacement at meter-scale resolution. We conducted a case study on the Yamal Peninsula, Russia, where we compare permafrost subsidence data from Sentinel-1 with various potential driving factors, including climate forcing data from ERA5-Land and geomorphology data from MERIT Hydro. A statistical approach is taken to analyse the relationships between different factors and their contributions to permafrost subsidence. The results demonstrate the high heterogeneity of permafrost subsidence in the form of probability distribution functions at ESM-scale resolution. Eventually, our study aims to obtain a parameterization for pan-Arctic permafrost subsidence that can be implemented into the ICON-ESM in order to close the gap in permafrost modelling between process- and ESM-scale. Reference: Turetsky, M.R., Abbott, B.W., Jones, M.C. et al. Carbon release through abrupt permafrost thaw. Nat. Geosci. 13, 138–143 (2020). https://doi.org/10.1038/s41561-019-0526-
Geophysics for urban subsurface characterization: Two case studies from Spain
Authors: Benjumea Beatriz , Marín-Lechado Carlos , Gaite Beatriz , Ruíz-Constán Ana , Schimmel Martin , Bohoyo Fernando , Spica Zack J.
Published: March 2024

This work focuses on two case studies carried out in Spain, where urban geophysics plays an important role in subsurface characterization. The application of geophysical methods in urban scenarios faces several challenges related to environmental noise (seismic or electromagnetic) or logistical constraints (lack of open space, complexity of instrumentation setup). In order to overcome these problems, research efforts are needed on both acquisition and processing aspects. The first case study presents the use of an innovative technology to acquire seismic data in the city of Granada. Distributed Acoustic Sensing (DAS) is based on the measurement of strain rate along a buried optical fiber that provides seismic measurements in a dense array of sensors. In our study, the fiber is a pre-existing underground telecommunications cable that crosses the city from northwest to southeast. We used 10 hours of ambient noise recordings to obtain subsurface reflection images that provide critical information for ground motion studies and seismic hazards in the metropolitan area. The second case study is located in the autonomous city of Melilla (North Africa). In this work, a gravimetric survey was carried out over the urban area with the aim of delineating the bedrock using 3D gravimetric inversion. We integrated the resulting geophysical model with surface geological observations, electrical resistivity tomography sections and borehole data to produce a 3D geological model of the city. Both studies highlight the suitability of geophysical information to complement the urban geological and geotechnical dataset to characterize and image the city underground.
Evaluating the application of deep-learning ensemble sea level and storm surge forecasting in the Baltic Sea
Authors: Barzandeh Amirhossein , Rus Marko , Ličer Matjaž , Maljutenko Ilja , Elken Jüri , Lagemaa Priidik , Uiboupin Rivo
Published: March 2024

The sea level predictions, which are done with state-of-the-art hydrodynamic models, often suffer from various uncertainties which are related to errors in atmospheric and open boundary forcing fields as well as in physical flux parametrizations. The errors in atmospheric prediction, and regional extreme phenomena like storm surges are due to models' approximated descriptions of the physical environments (e.g coupling with waves, atmosphere, ice, runoff), but also due to the stochastic nature of weather prediction, which is often treated as a single deterministic forecast in many applications. Moreover, the submission of correct warning alerts is subject to conversion to local reference level. The application of data-driven AI models can offer a promising addition to the classic hydrodynamic models in addressing these challenges. In the present study the sea level deep-learning forecasting model HIDRA2, demonstrates promising capabilities for forecasting storm surges in numerous coastal stations across the eastern coast of the Baltic Sea. Our comprehensive assessment of HIDRA2's includes intercomparison with the sea level forecasts predicted with the regional configuration of the NEMO 4.0 hydrodynamics model. Moreover the probabilistic storm surge forecast from the ensemble sea level predictions allows us to identify and refine the best sub-set of ensembles for accurately predicting storm surges. This case study will play an important role in guiding decision-making processes regarding the integration of deep-learning methodologies into the operational phase of sea level prediction, particularly in the Baltic Sea region.The EU funds this work under the agreement DE_330_MF between ECMWF and Météo-France. The on-demand capability proposed by the Météo-France led international partnership is a key component of the weather-induced extremes digital twin, which ECMWF will deliver through different phases of Destination Earth, launched by the European Commission. 
Anomalous Atmospheric Electric Field Just around the Time of Earthquakes: Case and statistical studies
Authors: Hobara Yasuhide , Watanabe Mako , Hongo Mio , Kikuchi Hiroshi , Tsuda Takuo , Hayakawa Masashi
Published: March 2024

In this paper, we report on the Atmospheric Electric Field (AEF) anomalies immediately before and after earthquakes (within 12 hours) in Japan. We demonstrate the results of a case study for several earthquakes that occurred close to our AEF observation network (within 100-200 km of the epicenter) under relatively fair local weather conditions. We found the common features for different earthquakes at different field sites e.g. 20~90 min period of clear anomalous signatures in wavelet spectrograms within a few hours around the main shock. Clear arrival time differences between AEF stations indicate propagating nature of observed AEF anomaly and enable us to calculate the propagation velocities and its occurrence timing. The observational results are compared with the dispersion relation of Internal Gravity Waves (IGW). Moreover, statistical results of the occurrence rate of the AEF anomalies support above mentioned results. Above-mentioned results may indicate the Lithosphere-Atmosphere Coupling, and we propose the physical mechanism of the observed electric field anomalies considering IGW originating from the epicenter region propagating over the field site and disturbing the local atmospheric electric field. 
Limits to adaptation strategies for heat impacts on rural labors filtered through stabilized climate mitigation scenarios. 
Authors: Buzan Jonathan , Silvy Yona , Larcoix Fabrice , Burger Friedrich , Terhaar Jens , Frölicher Thomas , Davin Édouard , Joos Fortunat
Published: March 2024

With global warming, increased heat stress will substantially impact the rural labor force. Understanding and quantifying this impact is difficult, especially due to regional differences: Does the temperature increase? Is there more solar exposure? Does humidity respond non-linearly with respect to temperature changes? Furthermore, humans are resourceful, and local environments could provide adaptation methods to decrease heat impacts. A policy-relevant assessment in the context of the Paris Agreement is even more difficult with existing CMIP-type simulations with prescribed greenhouse gas trajectories that lead to a different and often non-stable warming for each model. To resolve the impacts climate mitigation and adaptation on heat stress on warming levels with specific relevance for the Paris Agreement, we use the Community Earth System Model (CESM2) driven by emissions from the Adaptive Emissions Reduction Approach (AERA) to generate climate mitigation scenarios stabilized at 1.5°C, 2.0°C and 3.0°C of global warming. One form of adaptation to heat stress impacts is to use the local environment for cooling. Within CESM2, we compare the direct and indirect exposure to solar radiation within the vegetated canopy as an inexpensive form adaptation. To diagnose the heat stress conditions we use the International Organization for Standardization (ISO) 7243, the Wet Bulb Globe Temperature (WBGT), realized by first principles representation of the globe, dry bulb, and natural wet bulb thermometers utilizing CESM2’s temperature, humidity, winds, and radiation. The WBGT values are transformed into labor capacity using standardized algorithms (e.g. NIOSH or Lancet) and the above canopy (no adaptation) and below canopy (with adaptation) labor capacity are directly compared to each other. We show that the potential to adapt by using the local environment for cooling is not uniform across regions. For example, evaluating the hottest seasonal period (defined as a local summer), at the 3.0°C mitigation scenario in equatorial Southeast Asia, adaptation can save up to 50% of total labor capacity losses. However, in northern South Asia, adaptation saves only 10% of the seasonal labor capacity losses. These results demonstrate that rural laborers in some locations may have limited capacity to adapt to differing global mitigation strategies and may require mechanical cooling or other expensive forms of adaptation.
Global trend and drought analysis of near-natural river flows: The ROBIN Initiative
Authors: Kumar Amit , Hannaford Jamie , Turner Stephen , Barker Lucy J. , Dixon Harry , Griffin Adam , Suman Gayatri , Armitage Rachael
Published: March 2024

With hydrological extremes becoming more frequent and intense in a changing world, the impact on livelihoods, infrastructure, and economies is crucial. River flow data is a valuable resource and can be used to understand and analyse trends in both flow and extreme events. It is essential to systematically examine trends and anomalies within river flow across the globe. To capture the true natural trends, the river flow data should be from natural catchments and free from anthropogenic influences, such as the construction of dams, alterations in land use, and extraction of water from rivers. Special attention must be directed towards delineating these factors to enhance our understanding of the complex dynamics governing river systems. 

Existing challenges in attributing trends in river flows to climate change demands for a comprehensive, worldwide Reference Hydrometric Network (RHN) with minimal human impacts, to ensure integrity of climate change signals in river flow data. This global initiative, the Reference Observatory of Basins for INternational hydrological climate change detection (ROBIN) is a global collaboration to bring together the first global RHN. Currently consisting of partners from almost 30 countries spanning every continent, the first iteration of the ROBIN dataset is now available – a consistently defined network of over 3,000 near-natural catchments. 

The ROBIN team estimated the first truly global analysis of trends in river flows using near-natural catchments for periods of 40 (1975-2016) and 60 (1956-2016) years. This research showcases the first global drought assessment using the subset of ROBIN network, investigating variations in river flow trends and their impact on drought events, and trends at a global scale. The research focused on the spatial and temporal variability of trends and drought characteristics in different countries and hydro-belts across the ROBIN network. It also shows the great potential of serving as benchmark for future hydrological trend assessments. 

Efforts are ongoing to broaden the ROBIN network to bring together more countries, incorporating additional catchments representing diverse geographical characteristics. With the support of international organizations such as WMO, UNESCO, and IPCC, ROBIN establishes the groundwork for a sustainable network of catchments, enabling comprehensive assessments of climate-induced trends, variability, and occurrences of drought on a global scale. This initiative makes a substantial contribution to enhancing our understanding of the impact of climate change on river flows and the corresponding global patterns of drought. 
Spatio-temporal analysis of drought: A multidecadal study of European groundwater systems
Authors: Brauns Bentje , Bloomfield John , Hannah David , Marchant Ben , van Loon Anne
Published: March 2024

Groundwater, constituting approximately 65 percent of Europe's drinking water sources, plays a crucial role in sustaining both urban and agricultural needs. Particularly during periods of drought, groundwater abstraction becomes a key resource, alleviating adverse impacts on people's livelihoods. Recent European drought events, for example in 2003 and 2015, exhibited spatial coherence in surface water deficits across European regions, hinting at potential impacts on groundwater levels. However, the unique hydrogeological settings and recharge patterns of groundwater systems, coupled with diverse meteorological influences, can also lead to distinct spatial coherence in groundwater droughts. Despite these complexities, no comprehensive, decadal pan-European analysis of historic groundwater level data has been conducted until now.To bridge this gap, we conducted a continent-wide assessment of groundwater drought responses, based on over 3000 groundwater level timeseries spanning from 1986 to 2015, and providing the first extensive overview of historic groundwater droughts across Europe. Utilizing the Standardised Groundwater Index (SGI), the spatio-temporal analysis allowed for consistent comparisons of sites across disparate regions. Impulse response functions were used to identify differences in response times of the aquifers and cluster analysis of the standardized hydrographs allowed for the identification of spatially coherent 'type' groundwater hydrographs, characterized by differences in autocorrelation and reflective of continental-scale variations.Initial findings highlighted variations in groundwater system responses to meteorological drivers, distinctions between fast and slow responding sites and their spatial coherence. For example, differences in response times of the aquifers in Northern Germany produced local differences in the effects of the 2015 drought in this region and droughts in the late 90s showed good spatial coherence across large areas of Europe, but with distinctly smaller impact on groundwater levels in Balkan region. This analysis, coupled with an examination of driving factors, promises to enhance our understanding of how catchment and local characteristics influence groundwater responses. Additionally, areas particularly vulnerable to groundwater droughts will be identified, thus allowing for improved groundwater management.  
Towards a user-friendly NFDI4Earth OneStop4All portal to support researchers in Earth System Sciences in Germany
Authors: Anders Ivonne , Braesicke Peter , Degbelo Auriol , Hassler Sibylle K. , Henzen Christin , Kleeberg Ulrike , Ryan Marie , Thiemann Hannes
Published: March 2024

The National Research Data Infrastructure (NFDI) aims to create a sustainable and networked infrastructure for research data and helps to overcome the challenges associated with the storage, management and processing, security, and provision of research data in Germany [1]. It thus plays an important role in promoting open science and the exchange of FAIR research data. One of the NFDI initiatives is NFDI4Earth, which focuses on Earth System Sciences (ESS) [2]. Within the many ESS sub-disciplines, there is a diverse range of relevant high-quality data, services, tools, software, data repositories, as well as training and learning materials. Thus, it is not easy for researchers to find these various useful resources. Additionally, there is a lack of knowledge on how to use them due to an enormous diversity of standards, platforms, etc.The NFDI4Earth OneStop4All addresses these issues by serving as the primary user-friendly access point (Web portal) to the relevant ESS resources. It gives a coherent overview of the (distributed) resources for research data management (RDM), and data analysis/data science that are made available by the members of the NFDI4Earth as well as the Earth System Science (ESS) community. In particular, the OneStop4All provides access to data and software repositories, subject-specific RDM articles and a learning management system for open educational resources relevant to ESS researchers. In addition, it guides users through the NFDI4Earth resources according to their specific ESS RDM and data science needs and capabilities. The OneStop4All also promotes seamless access to a distributed user support network.The design and development of the OneStop4All is centered on the needs of the users. A good user experience requires an understanding of user behaviour, goals, motivations, and expectations and incorporating this knowledge into every stage of the design process. To achieve this, we use methods from user-centered design (UCD), complemented by knowledge and experience in various ESS disciplines from the members of the NFDI4Earth consortium, their extended scientific networks and by directly involving the community. We present the process of developing the user interface concept for the OneStop4All concerning usability and user experience and first insights into the platform are given. References[1] Agreement between the Federal Government and the Länder concerning the Establishment and Funding of a National Research Data Infrastructure (NDFI) of 26 November 2018: PDF-Datei [2] NFDI4Earth Consortium. (2022, Juli 7). NFDI4Earth - National Research Data Infrastructure for Earth System Sciences. Zenodo. https://doi.org/10.5281/zenodo.6806081 
Improving tidal interaction for compact N-body planetary system.
Authors: Revol Alexandre , Bolmont Emeline , Sastre Mariana V. , Libert Anne-Sophie , Tobie Gabriel , Blanco-Cuaresma Sergi
Published: March 2024

Recent JWST observations of rocky planets, such as TRAPPIST-1, and the increasing number of rocky planets discovered orbiting close to their host star, strongly motivates the improvement of tidal modeling.Beside, recent JWST observations of the thermal emission from TRAPPIST-1 b and c have provided constraints on their atmospheres (Greene et al. 2023; Ih et al. 2023; Zieba et al. 2023; Lincowski et al. 2023). In this context, It is crucial to use a coherent tidal model that encapsulates the complex response of rocky planets to stress, to understand the evolution of exoplanets and interpret new data.Our presentation will focus on recent developments on the implementation of the formalism of Kaula (1964) in the N-body code Posidonius (Blanco-Cuaresma & Bolmont 2017; Bolmont et al. 2020).This formalism consists in using a decomposition of the tidal potential into Fourier harmonic modes, which allows to account for the frequency dependence of the tidal response of rocky bodies.It makes it general enough to take into account for any type of internal structure, as well as the presence of ice or surface liquid water.We will present our results on the rotational state of TRAPPIST-1 planets, revisiting the assumption of the perfect synchronization state resulting from tidal evolution. Given that the rotational state influences the heat redistribution regime, precise estimation of their rotational state is critical.Various internal structures were explored with the Burnman code (Cottaar et al. 2014; Myhill et al. 2021)., considering compositions and core sizes compatible with mass and radius estimations from Agol et al. (2021).Our simulations showed that planet-planet interactions induce rapid variations in the mean motions of the planets. These variations occur too quickly for tides to maintain synchronized rotation states with the mean motion. This results in sub-stellar point drifts, causing planets to complete full solar days with periods ranging from 42 to 103 years depending on the planet. The competition between mean motion variations and tidal damping, and thus sub-stellar drifts, is contingent on the internal structure of the planet under consideration. As a result, remnant rotation is expected to facilitate the redistribution of heat on the planet's surface, modifying habitability conditions by mitigating the cold-trap effect on the night side (Turbet et al. 2016) and redistributing cloud formation on the day side (Turbet et al. 2021).Additionally, we will present preliminary results on the coupling between the spin and the orbital evolution of planets in compact mean motion resonances (MMRs), in particular with the presence of obliquity spin-orbit resonances (SOR), on time transit variations (TTV) and on the mean motion resonances for the TRAPPIST-1 system and the potential observability of such effects.
Monitoring of waterlogging in peatland under agricultural land use with Copernicus satellite data 
Authors: Tepaß Ariane , Tiemeyer Bärbel , Erasmi Stefan
Published: March 2024

The majority of peatlands in Germany were drained for agriculture and other land use and therefore make a significant contribution to greenhouse gas (GHG) emissions from land use, land use change and forestry (LULUCF). In Germany, they correspond to around 7.5% of the total emissions and 44% of emissions from agriculture and agriculturally used land (UBA 2022). According to the Climate Protection Act, the LULUCF sector should have a sinking capacity of 40 million tonnes of CO2 equivalent by 2045 (German Federal Council 2021). If the water level is raised accordingly, peatlands have enormous GHG reduction potential. A comprehensive data basis is needed for monitoring and evaluating climate protection measures on peatlands. In this context, the project “Copernicus lights green”, which focusses on satellite applications in grassland monitoring, developed satellite-based indicators with Copernicus data that are suitable for characterizing the hydrological condition of peatland areas under agricultural use. In addition to the intensity of use, reflected by mowing events, overflowing or surface water caused by waterlogging was considered as an indirect proxy for the water level of the organic soils.This contribution presents the method and results of an approach that estimates the duration and extent of waterlogged areas based on monthly composites of satellite data time series from Sentinel-1 and -2. The work builds on a random forest classifier using the Framework for Operational Radiometric Correction for Environmental monitoring (FORCE) (Frantz, 2020) that detects waterlogged areas in agricultural land on organic soils. Due to the heterogeneity of agricultural land use in Germany and its varying open ground frequency as well as the lack of availability of cloud-free images in the winter months, an approach considering a combination of two models according to the vegetation period was developed. It optimizes the selection of training data and input features in order to generate reliable information on a monthly basis. The chosen study area in Lower Saxony in Germany showed good prediction results in 2018 and 2019, whereas the resulting model predictions achieved an F1 score between 85-91% with a variability of 2-5%. This provides a methodological base for comprehensive monitoring.
Momentum Transfer Events and Other Disturbances in LRI Data
Authors: Bekal Pallavi , Misfeldt Malte , Müller Laura , Müller Vitali , Heinzel Gerhard
Published: March 2024

The Laser Ranging Interferometer (LRI) is a technology demonstrator instrument on board the GRACE-FO twin-satellite mission that has been in orbit since 2018. It uses laser interferometry to measure the range between the two satellites (GF1 and GF2) with a nanometer level of accuracy. The gravity field measurements using the ranging data quantify the spatial and temporal variation in the Earth's mass distribution.The change in the range measured by the LRI has gravitational and non-gravitational origins. Many non-gravitational effects, like atmospheric drag and thruster firings, are known and can be delineated from the LRI data. However, other sporadic instantaneous changes in the range are described as possible momentum transfer events (MTEs) candidates. Some potential sources are meteoroids and space debris's physical impacts on the spacecraft. To analyze MTE candidates, we first present the process of detecting them by correlating the LRI ∆v with that of the accelerometer (ACC) for both GRACE-FO spacecraft. Through this, 129 events were found on GF1 and 138 in GF2 between mid-2018 and the end of 2022. Some events show a better correlation between LRI and ACC data than others. Hence, further analysis is conducted by categorizing them accordingly and studying their spatial distribution and periodicity. The occurrence of many events coincides with the period of the beta angle of the sun. Structural changes in the spacecraft could cause these events upon exposure to solar radiation. However, many events have ∆v < 5 × 10 −8 m/s, which is too low to be considered an MTE. They are instead categorized as disturbances to the spacecraft. The origin of these remains unknown.Furthermore, simulations are performed using the ESA MASTER v8.0.3 to render the number of events per year that cause MTEs via physical impact during the same observation period. The observed events are consistent with the simulation for ∆v ≥ 5 × 10 −8 m/s. This analysis is beneficial in creating a repository of known effects in the first-ever space laser interferometer. In future missions, the knowledge of these occurrences in the LRI and ACC data will be helpful during post-processing.
Off-fault damage in the 2023 Kahramanmaraş (Türkiye) earthquakes from SAR images
Authors: Liu Jihong , Jónsson Sigurjón , Li Xing , Klinger Yann
Published: March 2024

Large strike-slip earthquakes are usually modeled as slip on localized planar fault planes within a homogeneous or layered elastic half-space. However, geodetic fault-slip inversions often show a shallow slip deficit, where the maximum slip is found at a depth of several kilometers with gradually decreasing slip towards the surface. High-resolution satellite images of earthquake surface ruptures also suggest a reduction in on-fault slip, often termed as off-fault damage or distributed deformation. In this study, we refer to this reduction in near-fault deformation as surface absent deformation (SAD). The presence of coseismic SAD, due to off-fault damange and/or compensated for by shallow interseismic fault creep and afterslip, holds significance for earthquake rupture processes, paleoseismology, and earthquake hazard assessments.In our study, we quantify the SAD along the main ruptures of the magnitude 7.8 and 7.6 Kahramanmaraş earthquakes, which occurred on 6 February 2023 near the Türkiye-Syria border, by mapping coseismic three-dimensional (3D) surface displacements using differential interferometry and pixel tracking of satellite synthetic aperture radar (SAR) images. The two earthquakes had a combined rupture length of approximately 500 km, exhibiting multi-meter surface fault offsets and diverse fault geometries, necessitating high-resolution deformation mapping near and away from the fault. We obtained the SAD distribution by analyzing fault-perpendicular profiles of fault-parallel displacement from the SAR-derived 3D displacements. For each profile, an arctan function was used to predict the near-fault (e.g., 0-5 km) elastic displacement based on the far-field (e.g., 5-50 km) observations, yielding an estimate of the lack of deformation close to the fault (i.e., the SAD). The results reveal a clear correlation between SAD and geometrical complexities along the two co-seismic ruptures. Using this strategy to determine the SAD, we find that about 35% of the surface fault slip is “missing” and expressed as SAD within a distance of 5-7 km from the coseismic surface ruptures. By comprehensively analyzing the interseismic, coseismic, and postseismic deformation in this area, we find that shallow interseismic fault creep and afterslip cannot explain the coseismic SAD and that it appears to be dominated by off-fault damage. Notably, existing research on off-fault damage has been concentrated within a range of only 1-2 km. Our results therefore underscore the significance of extending investigations of off-fault damage to 5-10 km from fault ruptures, and suggest that relying solely on on-fault offset measurements may lead to an underestimation of fault slip rate estimations by as much as one third.
Year-round Mediterranean Weather Regimes for exploring the occurrence of extreme precipitations
Authors: Giuntoli Ignazio , Corti Susanna
Published: March 2024

Weather regimes (WRs) provide useful information about large scale variability over relatively large regions, and they can be linked to extreme events occurring at the land surface, such as heat waves and extreme precipitations. Studies in this direction have shown how e.g., Euro-Atlantic WRs modulate flow dependent variability in North America and Europe and their links to extreme precipitation events. To date, the relationship of weather regimes specific to the Mediterranean with extreme events have not been sufficiently explored. The Mediterranean region is a hotspot for climate change and for its peculiar position, at the frontier between very different systems, it is influenced by a complex mix of large-scale variability processes. Under the hypothesis that these processes are explained better by considering atmospheric fields over the Mediterranean region, we proceed by extracting EOFs over the Mediterranean domain (25 to 50 North, and −10 to 40 East), and we identify, for the first time in this region, year-round weather regimes. This allows for a systematic detection of extremes that is not limited to a specific season but throughout the year. After describing each regime pattern and corresponding average conditions (temperature, precipitation), we explore their links to extreme precipitations in the area and finally compare results with EAT-WRs to assess which WR domain is more closely related to these events.
Refining the age-depth model of a marine sediment record in the Laptev Sea using Beryllium-
Authors: Nicolas Arnaud , Mollenhauer Gesine , Malter Maylin , Wollenburg Jutta , Adolphi Florian
Published: March 2024

In order to correctly determine leads and lags in the climate system and compare different proxy records over long time periods, it is important to build robust chronologies that can provide the temporal foundation for paleoclimate correlations between marine, terrestrial and ice-core records. One of the main challenges for building reliable radiocarbon-based chronologies in the marine realm is to estimate the regional marine radiocarbon reservoir age correction. Estimates of the local marine reservoir effect, ΔR, during the deglaciation can be obtained by 14C-independent dating methods such as synchronization to other well-dated archives. The cosmogenic radionuclide 10Be provides such a synchronization tool. Its atmospheric production rate is globally modulated by changes in the cosmic ray flux caused by changes in solar activity and geomagnetic field strength. The resulting variations in the meteoric fallout of10Be are recorded in sediments and ice cores and can thus be used for their synchronization.In this study we use for the first time the authigenic 10Be/9Be record of a Laptev Sea sediment core and synchronize it to the 10Be records from absolutely dated ice cores. Based on the resulting absolute chronology, the ΔR  was then estimated for the Laptev Sea during the deglaciation. The deglacial estimate for the benthic ΔR value for the Laptev Sea is 345±60 14C years, corresponding to a marine reservoir age of 864±90 14C years. We discuss the obtained ΔR in comparison to modern ΔR estimates from the literature and its consequences for the age-depth model. Our refined age-depth model can be used as a reference for the Laptev Sea and the wider Siberian regions of the Arctic Ocean.    
Versatile near-Earth environment of Radiation Belts and ring current 4D (VERB-4D) code
Authors: Himmelsbach Julia , Shprits Yuri , Haas Bernhard , Szabo-Roberts Matyas , Wang Dedong , Allison Hayley J. , Wutzig Michael
Published: March 2024

Ring current particles, which are heavily influenced by geomagnetic activity, excite plasmawaves (e.g., EMIC, chorus etc) and affect the terrestrial magnetospheric configuration, which modifies particle trajectories. During geomagnetic storms, specifically the recovery phase, the ring current becomes disturbed and decays via various loss processes (e.g., charge exchange, Coulomb collisions, and EMIC wave scattering). These disturbances in the ring current contribute significantly to the development of the Dst index. Since the ring current plays a crucial role in magnetospheric dynamics through its spatial and temporal evolution, understanding how it impacts the Dst index remains an ongoing topic of research.In this study, we present the first simulation results of the ring current using the Versatile near-Earth environment of Radiation Belts and ring current - 4D (VERB-4D) code, previously known as the Versatile Electron Radiation Belt - 4D code. Our simulations are compared to the Van Allen Probes HOPE and RBSPICE during a geomagnetic storm on March 17, 2013. We study the evolution of the MLT-resolved and average Dst index during the storm‘s recovery phase while examining the relative contributions of charge exchange, Coulomb drag, and radial diffusion.
Numerical investigation of the December 2019 seiche event in the Adriatic Sea
Authors: Bajo Marco , Arpaia Luca , Ferrarin Christian , Orlić Mirko
Published: March 2024

In this work, we present the preliminary results of a study of a series of seiches, which occurred during the month of December 2019 in the Adriatic. A  peculiar aspect of this event is that it was not preceded by any significant storm surge, which usually triggers the normal modes of the Adriatic Sea. With the aim of investigating the dynamics of the event, we used the sea levels observed at some coastal locations and a hydrodynamic finite element model. The model, already used in numerous studies of the area, was applied in a diagnostic way, by varying the forcing to demonstrate its importance for the event. We hypothesise that the first normal mode was excited by a variable wind forcing having a period close to the one of the main normal mode (about 21 hours). Consequently, the excitation of the normal mode was nearly resonant.
Ambient seismic noise tomography for mineral exploration in the Irish Midlands 
Authors: Ryberg Trond , Roy Corinna , Haberland Christian , Wellington Kacie , Moynihan Conor
Published: March 2024

Europe set out its goals for decarbonization in the EU Green Deal, which includes reducing net greenhouse gas emissions by relying more on renewable energy and green technologies. One goal of the EU project VECTOR (https://vectorproject.eu) is to test and develop passive, non-disruptive exploration methods to investigate Europe‘s raw material potential. We test the application of passive seismic imaging in the Irish midlands, which contain potential areas for zinc mineralization, one of the multiple raw materials needed for green energy technologies. More specifically, we apply ambient noise tomography to image the Earth’s subsurface and assess the utility of this technique for mineral exploration at depth: Thus, 210 temporary, continuously running digital seismic stations were deployed in the Irish midlands (north of Collinstown) in an area of ~8 x ~6 km, and recorded ambient noise data for ~6 weeks. We then extracted Rayleigh wave group velocities in the frequency range 0.625 – 10 Hz by cross-correlating the data (~42517 time series in total) and using the FTAN method. In the first step we used 1% of the data (long offsets) in a stochastic, transdimensional, hierarchical Monte Carlo search with Markov Chains to derive a three-dimensional shear wave velocity model. In the second step, we added shorter offsets, which did not lead to any significant changes in the 3D model. The velocity model shows distinct velocity anomalies down to approximately 1.6 km depth that correspond to features also seen in reflection seismic profiles provided by Teck Ireland Ltd, a subsidiary of Teck Resources Limited, that owns the project area and is an Associated Partner of VECTOR. This demonstrates the potential of low-cost passive seismic methods to investigate the Earth’s subsurface compared to expensive active seismic methods. We used synthetic 3D Checkerboard tests to assess which areas of the model are well resolved and we will further compare our models with other data sets, for example, petrophysical borehole data available in this area.
A regionalized framework for the Metastatistical Extreme Value Distribution applied to daily and sub-daily rainfall
Authors: Devò Pietro , Caruso Maria Francesca , Borga Marco , Marani Marco
Published: March 2024

The estimation of extreme rainfall based on short records is of considerable interest, above all in the context of rapidly changing rainfall regimes. Regionalization techniques, by trading space for time, allow us to partially overcome the lack of long observational records. The recently introduced Metastatistical Extreme Value Distribution (MEVD), a non-asymptotic extreme-value model, accounting for all observed rainfall events to infer the probability distribution of annual maxima, also contributed towards improving our ability to determine large quantiles based on short observational time series. Here we combine established regionalization techniques, aggregating data from multiple adjacent stations complying with set homogeneity criteria, with MEVD-based methodologies to explore how their joint use may further reduce the predictive uncertainty associated with the estimates of the probability of large events. In this work, we use precipitation data sets from a selection of worldwide regional station networks (Europe, USA, Middle East, and Asia) deployed in a wide range of elevations and different rainfall regimes. The temporal data resolution varies according to country ranging from sub-daily to daily scales. We analyze different event durations, between 5 minutes and 24 hours for the sub-daily scale, 1 day and 2 days for the daily one, and we implement a cross-validation procedure to evaluate predictive uncertainty. To evaluate possible improvements with respect to regionalization techniques based on traditional extreme value theory, such as the Generalized Extreme Value (GEV) distribution, we comparatively apply them and the proposed MEVD-based regionalization approach. The results show the benefits arising from the regionalization technique, which enhances the robustness of the models by increasing the consistency of the observed data population within the stations of the same cluster, particularly in the lowlands, where homogeneous regions can be more trivially identified. The proposed regionalization approach based on the metastatistic distribution brings a significant reduction of the estimation uncertainty for very high ratios between the forecasting return period value and the length of the calibration sample when compared to traditional methods. 
The Influence of Mantle Plumes on Plate Tectonics
Authors: Stotz Ingo L. , Vilacís Berta , Hayek Jorge N. , Carena Sara , Friedrich Anke , Bunge Hans-Peter
Published: March 2024

Our understanding of plate tectonics and mantle convection has made significant progress in recent decades, yet the specific impact of mantle plumes on plate tectonics remains a topic of controversy. The motions of the Earth’s lithosphere serves as a powerful lens into the dynamic behavior of the asthenosphere and deeper mantle, helping to untangle such controversies. Surface observations, therefore, provide important constraints on mantle convection patterns through space/time. Among these observations, the record of plate motion changes stands out, as it enables the geographical identification of torque sources. Consequently, surface observations provide essential constraints for theoretical models and numerical simulations.The analytical Poiseuille flow model applied to upper mantle flux in the asthenosphere offers a robust and testable prediction: Poiseuille flow induced plate motion changes should coincide with regional scale mantle convection induced elevation changes. Mantle plumes can generate such pressure driven flows, along with intraplate magmatism and induce buoyancy-driven uplift that leaves an imprint in the sedimentary record.Here, I will present a synthesis of geological and geophysical observations, supported by analytical calculations, to illustrate that a significant number of plate motion changes can be attributed primarily to torques originating from mantle plumes.
Evaluating the Vulnerability of Mountain Springs: A Case Study in Italy to Prioritize Conservation and Management Strategies
Authors: Battistel Maria , D'Alberto Lucio , Mario Giovanni , Marciano Raffaele , Dreossi Giuliano , Pozzobon Alessandro , Stenni Barbara , Masiol Mauro
Published: March 2024

This research introduces a methodology for evaluating the protection zone of vulnerable mountain springs using an hydrogeochemical approach. Mountain springs play a crucial role in maintaining the ecological balance and ensuring the well-being and resilience of communities residing in mountainous areas. These resources frequently serve as the primary freshwater supply in numerous mountainous regions, their impact extends beyond these areas by catering to diverse applications, including agriculture, farming, hydropower generation, artificial snowmaking, and industrial utilization.Despite their importance, mountain springs are under increasing threat due to climate change and human activities and thus need to be preserved and managed to ensure a sustainable use and conservation. In this study, we assess the vulnerability of two mountain springs located in a karstic water system in the Northern Italy mountainous region. Particularly we analyze the hydrogeological and hydrogeochemical parameters of the two mountain springs, together with the oxygen and hydrogen isotopic composition (δ18O and δ2H) and d-excess of both the springs and the rainwater of the area. The considered parameters were continuously measured from September 2018 to September 2021. The main goal is to assess the geochemical and hydrological processes that control the springs water quality and the isotopic composition of precipitation and use them for formulating effective springs protection measures.  Our results show that the vulnerability of mountain springs is influenced by various factors that include the use of the resource, the meteorological conditions, and the hydrogeology of the area. We propose a method that integrates the Vulnerability Estimator for Spring Protection Areas index with the use of the water stable isotopes to identify springs’ protection zones that takes in consideration the recharge area of the aquifers feeding the springs. Our study contributes to the development of a framework for assessing the vulnerability of mountain springs and highlights the importance of integrating the geochemical characteristics and the anthropic pressure in the conservation and management of these critical freshwater resources. This study is part of Next Innovation Ecosystem Program "Interconnected Northeast Innovation Ecosystem (iNEST)" supported by the European Union.