bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction and Evaluation of the Stochastic Model in Precise Point Positioning based on Triple-Frequency Geometry-Free Combination
Authors: Xiao Jingxin , Li Haojun
Published: March 2024

The Global Navigation Satellite System (GNSS) carrier phase and pseudorange measurements exhibit different levels of accuracy, and there are differences in observation accuracy among different observation systems, satellites and receivers. A reasonable stochastic model is crucial for improving Precise Point Positioning (PPP) results. We propose a method for constructing stochastic models in PPP using triple-frequency observations. By forming geometry-free and ionosphere-free (GFIF) combinations and subtracting inter-frequency clock biases (IFCB), the accuracies of phase and pseudorange observations are evaluated using residuals to determine weights. Data from 278 International GNSS Service (IGS) stations on September 1, 2023 are processed to calculate the accuracies of carrier phase and pseudorange observations in GPS, Galileo, and BDS-3 systems. The results show that the accuracies of carrier phase observations among different receivers are relatively close, while there are obvious disparities in pseudorange observation accuracies. The average Root Mean Square (RMS) of Galileo carrier phase and pseudorange observations is the smallest among three systems. In BDS-3 system, there are certain disparities in carrier phase observation accuracies among different types of satellites. Specifically, for LEICA and SEPT receivers, the average RMS of IGSO satellites is greater than that of MEO satellites. To validate the effectiveness of the proposed model, the static and dynamic PPP solutions are conducted using 80 IGS stations. The results demonstrate that compared to the empirical model, the proposed model shortens the average convergence time by 22.5%, 31.5%, and 24.1% in static PPP for GPS, Galileo, and BDS-3 systems, respectively. At 0.5h, the average three dimensions (3D) positioning accuracies improve by 2.1, 3.5 and 2.9 cm, respectively. For dynamic PPP within the range of 0.5 to 1 hour, the average RMS of the 3D positioning are reduced by 2.6, 4.7 and 3.0 cm, respectively. Furthermore, for multi-system PPP of GPS+Galileo+BDS-3, the average convergence time and positioning accuracy are also improved with the proposed stochastic model.
Scintillations in the Southern Europe during the geomagnetic storm of June 2015: analysis of a plasma bubbles spill-off using local data
Authors: Morozova Anna , Estaço Daniela , Spogli Luca , Barata Teresa
Published: March 2024

The sensitivity of Global Navigation Satellite Systems (GNSS)  receivers to ionospheric disturbances and their constant growth is nowadays resulting in an increased concern of GNSS-users about the impacts of ionospheric disturbances at mid-latitudes. The geomagnetic storm of June 22-23, 2015, is an example of a rare phenomenon of a spill-over of equatorial plasma bubbles well north from their habitual region of ~+/- 20º around the magnetic equator.We study the occurrence of small- and medium-scale irregularities in Southern Europe by analysing the behaviour of the amplitude scintillation index S4 and of the Rate Of Total Electron Content Index (ROTI) during the geomagnetic storm of June 22-23, 2015. To the scope, we leverage data obtained by local GNSS receivers for scintillation monitoring located in Lisbon (Portugal) and Lampedusa (Italy). Data is complemented with total electron content (TEC) data both from the local GNSS receivers and from global ionospheric maps.The multi-source data allows for a better understanding of the ionospheric dynamic during the studied event.
A Decision Support System for Forest Fire Danger Notices in Ireland 
Authors: Flattery Padraig , Finkele Klara , Downes Paul , Hally Alan , Nugent Ciaran
Published: March 2024

Since 2006 the Canadian Forest Fire Weather Index System (FWI) has been employed operationally at Met Éireann to predict the risk of forest fires in Ireland. Around 11% or 770,000 ha of the total land area of Ireland is afforested, but there are also large areas of open mountain and peatlands covered in grasses, dwarf-shrub and larger woody shrub type vegetation which can provide fuel for spring wildfires under suitable conditions. After winter, vegetation can be dead or have a very low live moisture content, and the flammability of this vegetation can be readily influenced by prevailing weather, especially following prolonged dry periods.Different decision support tools are available to different sectors, namely:The General Public: who have access to fire weather index meteograms on Met Éireann’s public website.
Local Authorities, who have access to the ANYWHERE multi-hazard warning system, which provides multiple sources of information about fire danger and propagation.
The Department of Agriculture, Food and Marine (DAFM), who are provided with information and additional support from National and European partners and networks.
DAFM is the Forest Protection authority in Ireland responsible for issuing Forest Fire Danger Notices which improve preparedness for fire responses and are based on a range of factors including information provided by Met Éireann who calculate the FWI and FWI components using observation data at synoptic stations, and the predicted FWI for the next five days ahead based on numerical weather prediction data. This allows fire responders to build resilience and prepare for impending fires.The FWI is determined based on the types of forest fuel and how quickly they dry out/get rewetted, and components of fire behaviour. The FWI represents the fire intensity as the rate of energy per unit length of fire front (kW/m). The components which provide the most accurate indication of risk under Irish conditions are the Fine Fuel Moisture Code and Initial Spread Index, based on the fuels involved and ignition patterns observed to date. Since 2022 Met Eireann provide the FWI as well as the individual components Fine Fuel Moisture Content and Initial Spread Index via the public website for synoptic stations. These indices are based on observations and a seven-day forecast into the future using ECMWF predictions. This allows all county councils responsible for wildfire preparedness to access this information swiftly and directly.Met Éireann also use the ANYWHERE multi-hazard warning tool which allows for visualisation of multiple fire-related risk factors and warning indices to be viewed simultaneously. The ANYWHERE system, in combination with our station-based forecast and antecedent conditions, provide fire managers and response teams with excellent information with which to make decisions.
Correlating different evaluation methods for SWC as support for soil processes modelling 
Authors: Innocenti Agnese , Pazzi Veronica , Fanti Riccardo
Published: March 2024

Soil erosion modelling has a large sensitivity to soil water content as it greatly affects soil erodibility. Knowing soil moisture and water content along a soil profile can help to understand the soil ability to absorb water before runoff occurs, then, to predict runoff and potential erosion.This study presents a combined approach of direct and indirect methods to monitor soil moisture content on a slope, with the goal of using this data in the future for modelling water erosion processes in soils.Generally, soil moisture data used for erosion models can be acquired through direct methods (e.g., gravimetric method, time or frequency domain reflectometry, moisture sensors) and/or indirect methods (meteorological data, remote sensing, electrical conductivity).In this research project, an experiment was carried out with the aim of combining direct and indirect methods to maximize the information on the rate of change of soil moisture in a 9*9 m plot by exploring depths from 0 to 50 cm. We used the water content sensor, SoilVUE10 by Campbell, recently released on the market, and based on Time Domain Reflectometry (TDR) technology conjointly with the Electrical Resistivity Tomography (ERT). Moisture sensors are known to create a disturbance in the ground, while geophysical techniques such as ERT are indirect, non-destructive measurements. Furthermore, they have the great advantage of being able to investigate a significantly larger area than classic humidity sensors.The conductivity varied in average between 0.02 and 0.08 S/m with a little more evident relationship between the values measured with the two methods in deeper layers than at soil surface (i.e., r=0.31 at -30cm).Overall, further investigations will be conducted, the ERT system needs data acquisition integration, i.e., remote data acquisition so that much more data can be acquired (at least one data set per day). The moisture values acquired by the SoilVUE10 probe require further analysis and comparison, possibly with other TDR probes. Furthermore, it may be necessary to install a surface moisture sensor capable to improve data acquisition even for the first 10cm soil layer.
Hydro-Morphodynamic Delta Modelling for Future Exploration Insights at Oxia Planum, Mars
Authors: Braat Lisanne , Wong Sabrina , Sefton-Nash Elliot
Published: March 2024

The European Space Agency (ESA) plans to launch the Rosalind Franklin rover in 2028. The aim of this mission is to search for biosignatures and to investigate Oxia Planum (Altieri et al., 2023). This landing site was chosen because it is one of the oldest Noachian terrains (4-3.6 Ga) altered by water, yet logistically feasible for landing and roving. Oxia Planum is rich in clays, hydrated minerals, suggesting the past influence of liquid water (Mandon et al., 2021). A river delta has been identified close to the landing site at the termination of Coogoon Vallis (Quantin-Nataf et al., 2021). The delta presents potential for preserving biosignatures either by covering underlying clays or in within its own deposits, providing protection from radiation and oxidation. Despite knowing that water played an important role at Oxia Planum, it is still unclear what the past fluvial and environmental conditions were like.Deltas on Mars are important targets for planetary exploration due to their indicators of past fluvial activity, contain a sedimentary record available to study, and have potential for preserving past signs of life. The observable delta deposits, captured by satellite and rover imagery, serve as key sources for deducing ancient fluvial and climatic conditions on Mars (e.g. Salese et al., 2020; Toffoli et al., 2021; Mangold et al., 2021). This study will use the observed river delta at Oxia Planum to investigate past fluvial and environmental conditions at the landing site. Specifically, this study aims to constrain the range of possible hydrological conditions in terms of duration of activity, flow energy conditions and water levels. These insights contribute to the strategic planning of the rover mission, aiding in the identification of drilling locations of interest.To investigate the Oxia Planum delta, we developed a 2D-horizontal hydro-morphological model. We used the numerical modelling software package Delft3D FM (by Deltares), which was amended for Martian gravity. We explored multiple scenarios including, different water levels in the basin, river discharges, sediment supply rates and grain sizes. Some scenarios aimed to replicate the final phase of delta activity, while others sought to reconstruct the evolution of older delta lobes. Although the preliminary results are subject to ongoing investigation, they hold promise for refining estimates (both lower and upper bounds) of fluvial conditions such as discharge, water level, sediment transport rates, morphological development, and duration of activity. Given the distinct sediment transport dynamics on Mars due to lower gravity (Braat et al., 2023), reliance on investigative modelling becomes imperative, as the direct use of Earth analogues is challenging.
Reconstructing Historical Flood Events: A Monte Carlo-Based Uncertainty Approach
Authors: Sabeti Ramtin , R. Kjeldsen Thomas , Stamataki Ioanna
Published: March 2024

Reconstructing historical flood events can offer critical insight into past hydrological responses to extreme weather, informing contemporary flood risk management and infrastructure design. This study employs reverse engineering, based on historical data such as recorded rainfall, flood marks, visual records, and eyewitness accounts to reconstruct a flood event. Historical data was collected by the team during a workshop with the local community. The approach involves hydrological (HEC-HMS) and hydraulic (HEC-RAS) models to simulate the flood event. The July 1968 UK storm, remarkable for record rainfall reaching 175 millimetres within 18 hours, caused extensive devastation in south-west England. This study focuses on reconstructing the 1968 flash flood on the River Chew, notably the peak hydrograph in the village of Pensford. A Monte Carlo simulation approach is used in conjunction with the HEC-HMS and HEC-RAS models to produce a range of potential input hydrographs with uncertainty input parameters (primarily event rainfall and Manning’s roughness) that match the historical evidence.  In particular, the Monte Carlo approach is implemented using a series of Python scripts enabling multiple HEC-RAS simulations to be conducted and the results synthesised in the form of an uncertainty analysis of key parameters such as peak flow. 
Deformation and reaction of plagioclase-rich rocks at conditions of the lower continental crust
Authors: Incel Sarah , Renner Jörg , Schubnel Alexandre , Labrousse Loic , Baisset Marie , Mohrbach Lisa Katharina
Published: March 2024

Due to contrasting results between laboratory tests, geophysical data, and field observations, the strength of the plagioclase-rich lower continental crust remains a topic of debate. It has been shown that its strength highly depends on the presence of fluids as they trigger metamorphic reactions that can result in permanent weakening. An important metamorphic reaction in the lower continental crust is the breakdown or hydration of plagioclase and the associated growth of epidote-group minerals, kyanite, quartz, and jadeite/albite. To investigate the impact of this particular reaction on the strength of the lower continental crust, we combined experimental work, i.e., Griggs-deformation tests, with extensive microstructural observations of the recovered experimental samples. Experimental conditions were 1 to 1.5 GPa confining pressure, 550 to 950 °C, and for the deformation tests, we used strain rates ranging from 10-6 to 10-5 s-1. Our results reveal two main findings. First, deformed plagioclase aggregates as well as deformed granulite drill cores show that deformation-induced features in plagioclase grains, e.g., cleavage cracks and twin boundaries, act as nucleation sites for metamorphic reactions and melting. Consequently, reaction can progress faster in deformed samples as the effective reactive surface area is increased relative to undeformed counterparts. Second, when deformed under identical experimental conditions, pure epidote aggregates are consistently stronger or show equal strengths than pure plagioclase aggregates. Hence, a partial plagioclase breakdown, i.e., the exclusive growth of epidote-group minerals at low reaction progress, is not expected to result in permanent weakening. This result further strengthens the idea that a process akin to Zener pinning is a viable mechanism to cause long-term weakening in rocks.
CFD modelling to investigate hydrodynamic forces on bridges in case of submergence and material deposition 
Authors: Petruccelli Natasha , Panici Diego , Domeneghetti Alessio , Brath Armando
Published: March 2024

Increasingly frequent and intense flood events, combined with the remarkable industrialization process of cities, are placing transportation networks under stress. The loads that roads and railways must resist are nowadays often greater than those considered for their design; furthermore, their state of ageing is such that any disturbance (flood, earthquake, landslide) could cause a total or partial interruption of traffic resulting in socio-economic losses.Bridges represent the most vulnerable component of a transport system and their failure can compromise the functionality of the entire network, as well as causing loss of life. During floods, bridges can be partially or completely submerged, having to withstand higher hydrodynamic loads which can lead to the collapse of the structure itself. Furthermore, accumulations of large wood and scour total around the bridge piers can reduce the load-bearing capacity of the structure and therefore its structural integrity.In this study, we investigated the hydrodynamic actions and the 3-dimensional flow field at a model bridge (comprising deck and pier) using CFD (Computational Fluid Dynamics) modelling. Drag and lift forces acting on the rectangular-shaped deck were estimated for different submergence values to evaluate the structure's maximum permissible load. In particular, drag and lift coefficients were calculated by simulating various flow conditions (Froude number varying between  0.16 and 0.50) and adopting three different turbulence models (RNG, k-ε, k-ω).In addition, the effect on the drag coefficient of the accumulation of large wood around the pier was also examined, considering different geometries. Numerical simulations, performed for both fixed and live river bed conditions, were validated using experimental data. However, the trends of the synthetic curves constructed so far have presented characteristics similar to those present in the literature, with all positive values ​​for the drag coefficient and negative ​​for the lift coefficient.  The emerging evaluations allow us to provide useful indications to designers to evaluate the possible state of stresses on existing bridges and improve knowledge for designing new ones.
Tropical land-to-ocean precipitation differences explained in the framework of the moisture-precipitation relationship
Authors: Schmidt Luca , Hohenegger Cathy
Published: March 2024

The highly nonlinear moisture-precipitation relationship P(r) is a simple statistical model for tropical precipitation P that takes column relative humidity r as its only input variable. Its simplicity and robustness make the relationship useful for conceptual models and as a tool for model diagnostics. We use 10 years of daily ERA5 Reanalysis data to test if P(r) can reproduce the tropical land-ocean contrast of precipitation which we quantify by the tropical precipitation ratio χ(t), defined as the ratio between the spatiotemporal mean rain rate over land and ocean. We find that P(r) can adequately reproduce both magnitude and phase of the average seasonal cycle of χ(t) as long as we take into account that P(r) gets modified by the presence of land and that the relationship varies seasonally over both land and ocean. Since the values of χ(t) indicate that precipitation is enhanced over tropical land, we investigate in a second step whether this enhancement is explained by the distinct P(r) relationships over land and ocean, i.e. whether it rains more over land than over ocean for a given value of r, or by distinct land and ocean humidity distributions, or both. Our results show that the influence of the land surface on P(r) has the effect of disfavoring precipitation over land rather than enhancing it. Precipitation enhancement over land, thus, stems from the distinct humidity distributions over land and ocean with the land distribution exhibiting a more pronounced tail towards high r values compared to the ocean distribution.
Constraining the basal sliding of alpine glaciers using adjoint-based inversions and automatic differentiation on GPUs
Authors: Chen Yilu , Utkin Ivan , Räss Ludovic , Werder Mauro
Published: March 2024

There are many uncertainties associated with natural processes governing the evolution of glaciers and ice sheets. Unknown parameters, such as basal drag or surface mass balance, can be estimated through data assimilation workflows coupled with physics-based models of ice flow. The multi-scale nature of ice dynamics and significant spatial and temporal variations in physical properties challenges accurate estimations of distributed fields of unknown parameters. High-performance computing and modern computational architectures such as graphics processing units (GPUs) enable efficient and scalable solvers for the ice flow.In this work, we introduce a novel GPU-accelerated inversion framework to enable a point-wise reconstruction of unknown parameter fields at high resolution. The inversion framework is based on the adjoint sensitivity method combined to a gradient-based optimisation. The derivation of the adjoint problem often represents a tedious task which limits the applicability of adjoint-based inversions to simplified ice flow models and hinders fast development. To address these limitations we use differentiable programming and the Julia language which permit automatic differentiation (AD) of arbitrary GPU code. Our GPU-based inversion procedure combines an automatically generated adjoint solver by the Enzyme.jl package using AD and a forward solver to retrieve the point-wise gradient we further use to minimise a cost-function.We demonstrate the capabilities of our inversion framework by developing a forward solver, based on shallow ice approximation (SIA), and several inverse models, utilising different assumptions about the ice flow. One inversion model assumes that the glacier is in a steady-state, which requires iterative solution of SIA equations. The inversion procedure estimates distributions of sliding coefficient, matching the observed ice thickness, glacier outline, and surface velocities. Another inversion model is based on a "snapshot" approach, in which the surface elevation is fixed from observations, and the sliding coefficient is solved to only match observed surface velocities. These two models represent two end members of the spectrum of data assimilation approaches, which will serve as building blocks for more complex workflows, such as transient evolution of glaciers.The feasibility of our inversion algorithms is validated through extensive testing on synthetic glaciers. Then we consider the application of our inversion approach to glaciers in the European Alps using remote sensing data. A map of sliding coefficients is reconstructed by matching the observed ice surface velocity and elevation. The successful application to real glaciers confirms that our inversion models are well suited for large scale and high-resolution simulations. We also present the performance testing results demonstrating close-to-optimal performance of forward and inverse models on NVIDIA GPUs.
Comparative analysis of conventional and machine learning techniques for rainfall threshold evaluation under complex geological conditions
Authors: Dal Seno Nicola , Evangelista Davide , Piccolomini Elena , Berti Matteo
Published: March 2024

The Emilia-Romagna Region in Italy faces significant challenges due to landslide hazards. With over 80,000 landslides identified in its mountainous regions, some areas see more than a quarter of their land impacted. Despite the generally slow nature of these landslides, they pose a considerable economic burden. For instance, in 2019, the region allocated 1 million euros for immediate safety measures, and it's estimated that an additional 80 million euros are needed to complete safety plans. This makes Emilia-Romagna one of the most landslide-prone areas globally. Factors like the region's geological makeup, increased land use, and climate change are exacerbating the issue. It's becoming evident that emergency measures alone are insufficient, and proactive prevention strategies are essential. Key efforts include better forecasting of rain-induced slope instabilities and predicting reactivations of dormant landslides and new failures. However, the unpredictable nature of landslides makes these goals challenging.The primary aim of this study is to create AI models to predict landslides in Emilia-Romagna, leveraging 75 years of data collected by the University of Bologna in partnership with the Regional Agency for Civil Protection and the Geological Survey of Emilia-Romagna. Various methods like Bayesian analysis, Neural Networks, XGBoost, TPOT, Random Forest, LDA, QDA, and Linear Regression have been employed. The findings suggest that landslides in this region are primarily driven by rainfall during the event and its location, while prior rainfall seems less critical. The research also found that after a dry summer, a rainfall event of 90-100 mm is typically needed to trigger a landslide, a threshold that decreases later in the year. The best algorithm had an F2 score test result of 0.6, meaning it could correctly predict a true positive (rainfall causing landslide) every 3 positive instances and correctly predict a true negative (rainfall not causing landslide) 95.5% of the time.
BepiColombo Mission Update
Authors: Benkhoff Johannes , Murakami Go
Published: March 2024

Following its launch, BepiColombo has already performed three flybys at Mercury. The next three flybys at Mercury are time wise very close together and are planned with about four months starting in September 2024. About 10 months after these flybys the orbit insertion preparation will start. When in orbit, BepiColombo with its state of the art and very comprehensive payload will perform measurements to increase our knowledge on the fundamental questions about Mercury’s evolution, composition, interior, magnetosphere, and exosphere.Although the two BepiColombo spacecraft are in a stacked configuration during the cruise and only some of the instruments can perform scientific observations, the mission produces already some very valuable results. As an example, Mercury’s southern inner magnetosphere, a so far unexplored region, has been observed by the BepiColombo ion and fields instruments during the pass.  Data taken during the Mercury's flybys revealed a magnetosphere populated by diverse populations and confirmed a really dynamic regime. BepiColombo is a joint mission between the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) for comprehensive exploration of planet Mercury. BepiColombo, has been launched on 20 October 2018 from the European spaceport Kourou in French Guyana and it is currently on a seven-year-long cruise to Mercury. BepiColombo consists of two orbiters, the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (Mio). In late 2025/early 2026 these orbiters will be put in orbit around the innermost planet of our Solar System. During the talk a status of the mission and results from science operations during cruise will be presented.
Climate informed non-stationary simulation of daily streamflow – a comparison of three stochastic models
Authors: Haberlandt Uwe , Jiang Ze , Brunner Manuela , Chartier-Rescan Corentin , Brandt Adina , Sharma Ashish
Published: March 2024

For optimal planning of reservoir design and management, long series or many realizations of daily streamflow are required. Stochastic streamflow models can provide such data. However, considering future changes in climate in these models is challenging. The objective of this study is to compare three non-stationary stochastic models with respect to their performance in simulating daily streamflow for current and future climate conditions. This comparison relies on two non-parametric approaches, namely the k-nn Bootstrap and Simulated Annealing optimization as well as a parametric model working in the frequency domain.All models are run under different experiments: (1) with observed climate from the German Weather Service for a reference and pseudo-future period and (2) with future climate simulations using data from climate models. The simulations from the three models are evaluated for general flow statistics considering current climate and observed changes for a pseudo future. As an additional reference, the HBV rainfall - runoff model driven by observed climate and climate model data is used. The testing of the methods is carried out for some mesoscale catchments in the Harz Mountains comprising streamflow gauges with long daily records. The ability of the stochastic models to simulate the changes for the pseudo future will be the core test for their applicability under changing climate conditions. The results are also expected to demonstrate advantages, disadvantages and limitations of the three methods.
Interdisciplinary collaboration to develop a robust and implementable monitoring, reporting, and verification (MRV) protocol for Ocean Alkalinity Enhancement (OAE)
Authors: Gill Sophie , He Jing , Yin Jennifer , Sutherland Kevin , Lambert Jonathan , Hacker Neil
Published: March 2024

The marine carbon dioxide removal (mCDR) industry is undergoing rapid growth, with many stakeholders deploying mCDR pilot projects. In order to establish a scientific basis for environmental safety and carbon accounting in mCDR, there is a need for rigorous, transparent and scientifically robust monitoring, reporting, and verification (MRV) protocols. These protocols seek to ensure responsible scaling of mCDR projects that have demonstrable net-negative atmospheric impacts. One of the main MRV challenges facing the mCDR pathway of Ocean Alkalinity Enhancement (OAE) is that direct measurements in the marine environment can be difficult to obtain. Here, we present the highlights of the first version of the Isometric OAE MRV protocol and focus on the process for interdisciplinary collaboration that informed decision-making and iteration towards the current version. We focus specifically on the development of guidelines for quantifying additionality, durability and uncertainty in the open system OAE pathway, and elaborate on our modeling requirements and benchmarks, as well as guidance on how models should be validated with environmental data. Ultimately, we aim to receive feedback on the protocol and our approach in order to apply this method to new versions and additional protocols and modules across mCDR and other CDR pathways. 
Linking long-term magma evolution and short-term volcano deformation 
Authors: Weber Gregor , Biggs Juliet , Annen Catherine
Published: March 2024

Volcanoes often change shape over timescales of months to decades, and such signals are likely influenced by the long-term physical evolution of magmatic systems over hundreds of thousands to millions of years. The link between these different timescales is often overlooked. In this presentation, I will show how volcanic surface deformation in response to a sudden overpressure at depth evolves over the long-term history of magmatic systems. To do this, I integrate thermal models of large-scale magma system evolution with thermo-mechanical simulations of surface deformation. We examined how changes in magma flux, magmatism duration over hundreds of thousands of years, and the depth of an overpressure source impact post-injection viscoelastic surface movement over a 10-year period. Our findings show that the duration of the long-term magmatic activity and magma supply rate significantly affect surface deformation over timescales of years. The results show that due to thermal heterogeneity in the crust, asymmetrical patterns of surface deformation can emerge in time due to viscoelastic processes, potentially similar to temporal patterns of magma movement. When uplift originates from deep sources (around 10 or 15 km below the surface), deformation follows a consistent uplift trend, dissipating within a few years with little dependence on past magma flux or system lifespan. Conversely, shallow sources (around 5 km below) display a strong dependence on long-term magma supply rate and system lifespan, resulting in distinct patterns of post-intrusive subsidence and subsequent uplift for colder magma systems, or exclusive uplift for hotter and longer-lived systems. These findings align exceptionally well with the deformation behaviour and geophysical tomography at Tullu Moye and Aluto volcanoes in the East Africa Rift. In conclusion, understanding how long-term magmatic processes interact with short-term volcano deformation is crucial for interpreting signals of volcanic unrest.
Exploring Diverse Perceptions of Multiple Risks among the Public in Rome
Authors: Lucantonio Mara , Ridolfi Elena , Cicini Patrizia , Russo Fabio , Napolitano Francesco
Published: March 2024

Risk is given by the combination of exposure, hazard, and vulnerability, and it is perceived by individuals in different ways. Some people may be unaware of the potential occurrence of a given hazard, while others may misjudge their level of exposure, vulnerability, or both. The knowledge of the population’s risk perception is a fundamental aspect for the analysis of potentially catastrophic phenomena and for the development of prevention policies to intervene and mitigate the expected damage. Questionnaires are widely used in social science research to acquire information about the attitudes, social characteristics, beliefs, and behaviors of participants. This information when combined through a mixed method can provide robust, comprehensive, and quantifiable results, adding a valuable perspective for the development of appropriate hazard mitigation and adaptation strategies. Here we present a case study that involves the analysis of a data set based on a questionnaire submitted to around 300 citizens of the city of Rome (Italy) in spring 2023. The proposed questionnaire investigates specific areas, which are: experience and knowledge of the phenomena, probability of occurrence perceived by the respondent, potential impact, and preparedness to deal with the phenomena.The use of questionnaires to study citizens’ perception of both natural and man-made hazards enables the acquisition of valuable information for authorities dealing with emergency management. The resulting dataset has the potential to improve the communication efficiency between authorities and citizens in risk situations, and provide relevant information for future studies relying on the knowledge of citizens’ risk perception.
Recent improvements in gravity precision from CG-6 sensors
Authors: Eiken Ola
Published: March 2024

Gravity sensors for high-precision monitoring or mapping can be grouped into 1) Relative spring, 2) Absolute free-fall, 3) Absolute cold atom, and 4) Superconducting. While all can provide valuable data, few comparisons of performance or cost have been published. Here we report on performance of CG-6 relative gravimeters and discuss how it relates to other sensors.The Scintrex CG-6 sensor has weight of 5.5 kg and volume of 10,8 litre, which is less than previous quartz sensors. While the manufacturer specifies 5 µGal repeatability, Francis (2021) reported better performance and improved drift, noise level, tilt susceptibility and temperature influence. Mao et al., (2022) reported uncertainty down to 0.1 µGal in the laboratory. We have analysed more than 2000 survey records from as diverse environments as the desert and the seafloor. Station repeatability is a robust measure of the precision for surveys with multiple station visits and sensors. Data redundancy allows in-situ calibration of scale factors and parameters for tilt and temperature corrections. Up to 10oC temperature difference between night and day gave no remaining correlation between sensor temperature and gravity residuals, but some diurnal drift periodicity, and repeatabilities
Satellite-based monitoring of the world’s largest terrestrial mammal migration using deep learning 
Authors: Wu Zijing , Wang Tiejun , Zhang Ce , Duporge Isla , Gu Xiaowei , Hughey Lacey , Stabach Jared , Skidmore Andrew , Hopcraft Grant , Atkinson Peter , McCauley Douglas , Lamprey Richard , Ngene Shadrack , Gong Peng
Published: March 2024

Accurate, reliable, and up-to-date information on wildlife populations is crucial for biodiversity conservation in the face of unprecedented biodiversity loss worldwide. However, monitoring wildlife populations at large scales remains challenging. Advances in satellite remote sensing, particularly very-high-resolution satellite data, offer new opportunities for monitoring wildlife from space, and new machine learning techniques present great potential for detecting wildlife with remarkable speed and accuracy. Here, we introduce a deep learning pipeline for automatically detecting and counting large migratory ungulate herds (wildebeest and zebra) at the individual level in the Serengeti-Mara ecosystem from submeter-resolution satellite imagery. We apply the pipeline to implement the first-ever population census of large-size ungulates in the Serengeti-Mara ecosystem through a satellite survey and generate the total count of the whole population. The model shows robust performance across diverse landscapes with an overall F1-score of 84.75% (Precision: 87.85%, Recall: 81.86%) on an independent test dataset containing 11,594 animals and achieves good transferability spatially and temporally. This research showcases the capability of satellite remote sensing and deep learning techniques to accurately locate and count very large populations of terrestrial mammals in open landscapes. It provides a new perspective on monitoring wildlife populations and animal migration, which will facilitate the understanding of animal behavior and ecology as well as improve the conservation of the whole ecosystem in the face of rapid environmental changes.
Investigating river-restoration-effects on riverbed-stability by physical modelling
Authors: Unrau Silas , Venuleo Sara , Derungs Guido , Lebrenz Henning
Published: March 2024

This study shows how experimental results provide fundamental insights in the challenge of river revitalisation, and thus represent a powerful tool to guide engineers’ actions. Results concerns a study case, namely the “Wiese Vital” project, a restoration project in Basel area (Switzerland), with the objectives of safeguarding Basel's drinking water supply while revitalizing its watercourse and providing flood protection.The planned revitalisation measures involve the reconstruction of the Wiese riverbed, the introduction of structures to improve its morphological variability and the replenishment of fine sediment to improve the spawning habitat of native fishes.The new Wiese riverbed will consist of a coarser sediment layer, about 1.2 meters deep, overlaying a layer of finer sediments, meant to protect the underlaying aquifer from undesirable water infiltrations and thus to ensure Basel's drinking water supply safety. The stability of the coarser layer was investigated using a physical model in scale 1 to 20, built in the hydraulic hall of the University of Applied Sciences and Arts Northwestern Switzerland.Experiments investigated the stability of the coarse protective layer in presence and in absences of revitalization measures: with and without “ecological” structures and before and after the addition of fine sediments.Results revealed that wrong placement of “ecological” structures can cause local erosion and threaten the stability of the riverbed. Moreover, they provided useful insights on the response of a coarser riverbed to the input of fine sediments.
Case study on the multi-year geophysical and acoustic survey in a gas flare site on the southeastern continental shelf of the East Sea, Korea
Authors: Kim Young-Jun , Veloso Alarcon Mario Enrique , Kong Gee-Soo , Chun Jong-Hwa , Cukur Deniz , Yoon Youngho , Yoo Dong-Geun
Published: March 2024

Shallow gas escaping from the seafloor is normally observed in poor sedimentary layers and geological structures accompanied by faults, cracks, and fractures. Gas venting, the migration of the fluid between pores, causes seafloor deformation such as pockmarks and can trigger large-scale geohazards such as submarine sliding and tsunamis, so multi-year monitoring is required.After first discovering a gas flare in the southeastern continental shelf area of the East Sea, Korea in 2019, we conducted multi-scaled seismic and acoustic surveys using R/V TamhaeⅡ from 2021 to 2023, except for 2020. In 2019, EK60, sub-bottom profiler (SBP), and high-resolution seismic (HRS) data were acquired, and EK60 and SBP data were acquired in 2021. In 2022, EK60, multi-beam echo sounder (MBES), SBP, and conventional seismic data were acquired, and in 2023, EK60, MBES, and SBP data were acquired. In 2019 and 2021, MBES data was only acquired to detect seafloor deformation such as the pockmark, while water column data using MBES began to be recorded to detect flares from 2022. The flare size from the seafloor to the sea surface was measured in the EK60 data, while the quantification study on the gas flow rate using the ESP3 software and the VBALab plugin has been tried since 2022. Through EK60 data acquired over 4 years, it can be estimated that gas venting periodically rather than continuously. MBES data presents evidence of a lot of gas-related seafloor deformation in the study area. Since the first exploration of a new R/V TamhaeⅢ installed EK80, parametric SBP, and acoustic Doppler current profiler (ADCP) will begin this May, we expect that a high-quality seismic and acoustic dataset will be obtained for the site of gas flare. For further research, it will be necessary for sea-water and geological sampling to analyze gas components, and detailed monitoring using ROV and seafloor observation systems installed with a camera should be accompanied to quantify the gas flow rate.
Localizing slow deformation holds crucial information related to seismicity patterns precluding brittle failure in crystalline rocks
Authors: Selvadurai Paul Antony , Salazar Vasquez Antonio Felipe , Bianchi Patrick , Madonna Claudio , Germanovich Leonid , Puzrin Alexander M. , Rabaiotti Carlo , Wiemer Stefan
Published: March 2024

A growing number of observations made using geodetic approaches have been able to detect large preparatory regions that experience accelerated deformation prior to and in close proximity to an earthquake’s hypocenter. An uptick in localized seismicity has also been observed in these regions and represents an opposite end-member of the spectra of deformation, in both space and time, from the opposite broad and slow process. If and how these preparatory observations are linked are not well understood. To study this, we conducted a triaxial experiment on a granitic rock sample instrumented with calibrated acoustic emission (AE) sensors and a distributed strain sensing (DSS) method using fibre optics. These two technologies were sensitive to seismic (100 kHz to 1 MHz) and aseismic (DC to 0.4 Hz) deformation at our sample scale and these were monitored as it was loaded and experienced brittle shear failure. DSS measurement allowed us to visualize the emergence of slow, heterogeneous strain fields that localized well before the failure of the sample. In the early stages of localized deformation, the regions exhibiting preferential damage were growing and doing so without producing seismicity. However, when approaching failure, these regions accommodating slow deformation began to accelerate and now produced clusters of seismicity. The cumulative seismic moment of the precursory seismicity was a fraction of the total anelastic deformation (< 0.1%) precluding the runaway dynamic failure. We also examined the clustering and frequency-magnitude distribution of the seismicity with respect to the localized strain field. In the later stages, moments prior to nucleation, the b-value begins to drop and becomes anti-correlated to the rapidly accelerating average volumetric strain rate measured using the DSS array. This observation better constrains the hypothesis that dilation of the relatively large preparation zone can host larger precursory earthquakes therein. These findings can help constrain models that better replicate the physics associated with the large spectrum of brittle deformation and will in turn help with our understanding of preparatory earthquake processes.
A 25-year assessment of Hot and Dry Weather Compound Events in Europe using Earth Observation 
Authors: Fluck Elody
Published: March 2024

 Weather Compound Events (WCE), broadly defined as “the combination of multiple drivers and/or hazards that contributes to societal or environmental risk” [1], contribute to important societal impacts and widespread economical damages. However, the underlying mechanisms and complete storylines of these events are complex and not well understood yet.In this study, we build an 25-year database of co-occurrent hot and dry compound events (HDCE) including heatwaves, droughts, dust storms and wildfires affecting Europe and the Mediterranean Basin from 2003 to 2020. based on Earth Observation exclusively. Individual natural hazards were systematically identified by a spatial and temporal matching algorithm applied on consistent ESA CCI Earth Observation datasets. The resulting individual natural hazard masks were then overlayed over Europe and permitted to identify regions simultaneously affected by two or more natural hazards on a daily basis. The climatology revealed HDCE hotspots among others in Northern Italy, Balkans and Caucasus regions.Characteristics of HDCE such as their duration, intensity and spatial extension are stored in the database. HDCE could also be associated with a severity index to aid comparison across events.Long-term statistics of the generated HDCE have shown a high interannual variability with HDCE being more frequent during the 5 last years rather than two decades ago.The large-scale preconditions preceding and occurring during HDCE are investigated as well in this study and revealed systematic patterns in the atmospheric dynamics. [1] Zscheischler, J., Martius, O., Westra, S., Bevacqua, E., Raymond, C., Horton, R.M., van den Hurk, B., AghaKouchak, A., Jézéquel, A., Mahecha, M.D. and Maraun, D., 2020. A typology of compound weather and climate events. Nature reviews earth & environment, 1(7), pp.333-347.
The development of kinematic shear-stress free faults 
Authors: Koehn Daniel , Hafermaas Daniel , Koehler Saskia
Published: March 2024

Faults are normally thought to present shear fractures that develop at an angle to the main principal stresses, so that they have shear stresses active parallel to the fault plane and thus move. Here we present two “fault” features that deviate from this principle, they develop not due to stress but during kinematic movement, they are both oriented parallel to two of the main principle stresses and as such have no shear stresses in their planes. On the large tectonic plate scale one of these features are the well known transform faults between mid ocean ridges. The ridges themselves are extensional features with the lowest principle stress perpendicular to the ridge. Transform faults are oriented perpendicular to the ridges and show movement only or mainly between the ridges where the plates move in opposite directions. These are faults that do not develop due to shear stress, they develop only because of differential movement and are therefore only or mainly kinematic. On the small scale a very similar feature is the side of a stylolite tooth. Stylolites are dissolution features, they are thus in a way the opposite to mid ocean ridges and have the largest principal stress oriented perpendicular to the stylolite plane. Due to differential movement and growth of the stylolite roughness they develop steep teeth where the sides of teeth become oriented perpendicular to the stylolite plane. These are also movement surfaces or “faults” that have no shear stress.What does this mean for stress inversion analysis? At least stylolite teeth show a quite pronounced set of striations on their sides and slikolites are also often developed on fault planes, at least in limestone. How do we separate a purely kinematic from a stress-related fault? This discussion and the potential consequences for stress inversion studies is not new, but remains to be very important and should be debated.