bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of point and bounding box annotation methods to detect wild animals using remote sensing and deep learning
Authors: Xu Zeyu , Wang Tiejun , Skimore Andrew , Lampery Richard
Published: March 2024

The point and bounding box are the two widely used annotation techniques for deep learning-based wild animal detection using remote sensing. However, the impact of these two annotation methods on the performance of deep learning is still unknown. Here, using a publicly available Aerial Elephant Dataset, we evaluate the effect of two annotation methods on model accuracy in two commonly used neural networks (YOLO and U-Net). The results show that when using YOLO, there are no statistically significant differences between the point and bounding box-based annotation methods, as indicated by an overall F1-score being 82.7% and 82.8% (df = 4, P = 0.683, t-test), respectively. While when using U-Net, the accuracy of the results based on bounding boxes with an overall F1-score of 82.7% is significantly higher than that of the point-based annotation method with an overall F1-score of 80.0% (df = 4, P < 0.001, t-test). Our study demonstrates that the effectiveness of the two annotation methods is influenced by the choice of deep learning models. The result suggests that the deep learning method should be taken into account when deciding on annotation techniques for animal detection in remote sensing images.
Spatial correlation between landslides and geotechnical factors using Random Forest and SHAP
Authors: Tzampoglou Ploutarchos , Loukidis Dimitrios , karalis Konstantinos , Anastasiades Aristodemos , Tsangaratos Paraskevas
Published: March 2024

The activation as well as the consequences of landslides are difficult to predict, as they depend on factors characterized by large variability and uncertainties. The aim of this study is to establish a correlation between geological, geotechnical and geomorgpohlogical characteristics and the spatial distribution of recorded landslides.The study area is located in the southwestern (SW) part of the island of Cyprus, covering an area of 552km2. During the past years, more than 1800 landslides, active and inactive (dormant and relict), have been recorded within this area through detailed mapping based on field observations, rendering the area an ideal test bed. At the beginning of this research study, all recorded landslides were digitized in raster format. Consequently, the study area was partitioned into 15 x 15m size cells having three classes: no landslides, inactive landslides and active landslides. Additionally, regarding the geological aspect, polygons encompassing 100% rock mass formations within recorded landslides were categorized as rock mass landslides, while the rest were characterized as landslides in argillaceous (soft rock and soil) materials. A series of correlation analyses were conducted using the Random Forest and SHAP (Shapley Additive explanation) methods.Considering the outcomes of the Random Forest method in argillaceous materials, it turns out that the most important factors for both active and inactive landslides are the Plasticity Index (PI) and the clay fraction (CF), followed by the factors associated with the geomorphology and the bedding structure (e.g. slope angle and bedding dip). The ranking results for inactive and active landslides in rock mass show that the most important factor is the Uniaxial Compressive Strength (UCS), followed by the Geological Strength Index (GSI). Furthermore, the orientation (azimuth) difference between slope and bedding dip (dip direction difference) appears to be more important than the slope angle.Similar ranking results were obtained using the SHAP method for argillaceous materials. Regarding the contribution of each factor in the inactive landslides, it appears that the PI and the slope angle increase proportionally to the possibility of landslide occurrence, while the CF does not exhibit a specific trend. Regarding the dip direction difference, small values contribute more to the occurrence of landslides. The active landslides show a similar picture, but with the CF exhibiting a stronger correlation than in the case of inactive landslides. According to the SHAP analysis for rock mass, the parameters of importance in both inactive and active landslides are UCS and GSI, followed by the slope angle and the dip direction difference.This research was funded by the European Commission (Marie Sklodowska-Curie Actions, Hybland-Society and Enterprise panel, Project No.: 101027880).
Singular Vector Decomposition (SVD) of satellite datasets: relation between cloud properties, radiative fluxes and climate indices.
Authors: Carboni Elisa , Thomas Gareth , Siddans Richard , Kerridge Brian
Published: March 2024

We describe a technique, singular vector decomposition (SVD), that can identify the spatial patterns that best describe the temporal variability of a global satellite dataset. These patterns, and their temporal evolution are then correlated with established climate indices. We apply this technique to datasets of cloud properties and radiative  fluxes over three decades ((A)ATSR/SLSTR, MODIS, IASI and CERES), but it can be more generically used to extract the pattern of variability of any regular gridded dataset such as different parameters from satellite retrieval and models.Leading singular vector for independent global data sets on both cloud properties (cloud fraction, cloud-top height) and TOA radiative fluxes, from polar orbiting satellites, covering different time periods is strongly correlated with ENSO index.SVD approach can provide incites into the underlying causes of observed changes in a particular dataset and provide a new tool in using global satellite observations in assessing global climate model (GCM) performance.
 evapotranspiration measurements at the landscape scale using a Micro-Wave scintillometer prototype: Evaluation from two field campaigns.
Authors: Cohard Jean-Martial , Barral Hélène , Coulaud Catherine , Mercier Bernard , Regneau Davy , Arrivé Jacob , Lohou Fabienne
Published: March 2024

Quantification of evapotranspiration over complex terrain is still challenging because all the known methods are indirect and rely on strong assumptions. The bichromatic scintillometry method, combining optical/near-infrared and microwave scintillometers, is probably one of the closest methods to the turbulent theoretical framework as it measures turbulent parameters for temperature and moisture fluctuations. However, since its description in the 90s, very few works have been published using this method, mainly because of the availability of manufactured instruments but also because of technical and methodological issues.In this study we present evapotranspiration series from two different campaigns with the combination of two scintillometers operating, one in the near infra-red domain and the other in the radiofrequency domain (94GHz), a prototype developed in collaboration with the Rutherford Appleton Laboratory (UK). The first 18-month time series has been measured over a crop mosaic These instruments have been installed in the Critical Zone observatory Oracle, located east of Paris in the Seine Catchment, and have run continuously since May 2016 to the end of year 2017 on a 4.5km pathlength. The data processing has been developed from raw received intensity data logged at 1kHz for both scintillometers. Turbulent fluxes have been processed from Cn² measurements using the bichromatic method. The data processing toolbox has been fully developed at IGE. Fluxes are then compared with aggregated fluxes from Eddy-Covariance stations representative of the different land cover within the footprint. Results are very encouraging with very good energy balance closure on short periods. However an underestimation of fluxes during summer times suggests some possible saturation impacts. To address this issue we installed a renewed scintillometry setup on a shorter 600m path length at the P2OA facility site near Lannemezan (South of France). The presentation will focus on these new results. 
Object- and Image Endmember-based Riparian Forest Classification of Narrow-Band UAS Image Data: A Case Study of the River Gail and River Drau, Austria
Authors: Filippi Anthony , Güneralp İnci , Castillo Cesar , Ma Andong , Paulus Gernot , Anders Karl-Heinrich
Published: March 2024

Studies that directly compare classification accuracies of object-based image analysis (GEOBIA) and endmember-based algorithms for the exploitation of very-high-spatial-resolution (VHR) images (e.g., unmanned aircraft systems (UAS) images) are quite limited. We employ an endmember-extraction algorithm in conjunction with an endmember-mapping method, and we separately utilize a multiresolution segmentation/object-based classification algorithm. We then classify riparian forest and other land covers and compare the classification accuracies obtained from the application of these respective classifiers to narrow-band, VHR UAS images acquired over two river reaches (of the River Gail and River Drau, respectively) in Austria. We determine the effect of pixel size on classification accuracy and assess performances associated with multiple image-acquisition dates. Our results indicate markedly higher classification accuracies for the GEOBIA approach, relative to those of the endmember-based method, where the former generally entails overall accuracies in excess of 85%. Poor endmember-mapping classification accuracies are most likely a function of: the very small pixel sizes associated with the UAS images; the large number of information classes; and the relatively small number of (albeit narrow) bands available for analysis.
Multi-scale study on fluid-rock interaction in caprock and reservoir rocks for enhanced CO2 sequestration
Authors: Annan Prescelli , Madonna Claudio , Rinaldi Antonio Pio , Zappone Alba
Published: March 2024

In the context of geological CO2 sequestration, understanding the complex interaction between reactive fluids and the rock matrix is pivotal in efficient and safe carbon storage. This paper presents a recently initiated research plan, spanning laboratory and pilot scale, covering two main scenarios: A) reactive reservoir rocks (e.g. basalt and peridotite), and B) claystone saline aquifers with sandstone reservoir rocks and claystone caprock. To investigate the specific effects of CO2 exposure on rock properties, we propose a 1-2 year exposure experiment on intact rock core samples. The experiment will be conducted using a batch reactor system equipped with continuous pH monitoring and carefully controlled to replicate in situ salinity, pressure and temperature levels. Before, during and after exposure, samples will be analysed using CT scanning to detect changes in porosity, and mechanical and physical properties will be assessed before and after exposure. Preliminary characterisation of the cores prior to exposure to CO2 will also be presented.In parallel decameter scale experiments spanning many months of CO2 injection are conducted at the Mont Terri underground rock laboratory in Switzerland. The experiments involve observing the injection of CO2-saturated brine into a fault zone within Opalinus Claystone—an analogue caprock. This contributes to a more comprehensive understanding of fluid injection on fault reactivation, particularly within the context of leakage processes at shallow depths crucial to CO2 storage security. Preliminary results on clay deformation in response to rapid increase of injection pressure will be presented.This research plan aims to understand reactive processes in different geological contexts fundamental to carbon storage strategies. Operating at multiple scales - from laboratory to pilot scale analysis - our study aligns with the session's broader goal of advancing the understanding and predictive capabilities of coupled processes induced by geoenergy applications. By sharing preliminary results and fostering collaboration, we aspire to maximise the scientific results of our laboratory experiments and contribute to the scientific community's search for sustainable solutions in carbon storage strategies.
Optimization of GRACE-based mass anomaly estimates using the first-order Tikhonov regularization, with application to the Greenland Ice Sheet
Authors: Ditmar Pavel
Published: March 2024

It is common to convert GRACE-based level-2 data product (spherical harmonic coefficients) into mass anomalies at the Earth’s surface using spherical harmonic synthesis. We claim that it is more appropriate to use for that purpose a least-squares adjustment (which can be understood in this context as a variant of mascon approach). Among other, this allows one to take into account the stochastic model of errors in the spherical harmonic coefficients, as well as a various physical constraints, such as geometry of coastal lines, geometry of deserts, etc. The latter constraints can be implemented, e.g., by introducing a spatially-varying first-order Tikhonov regularization. We apply such an approach to make a state-of-the-art estimate of Greenland Ice Sheet (GrIS) mass losses.First, a numerical study is carried out to optimize the spatially-varying regularization and demonstrate the performance of the developed approach. We show, among other, that the optimal regularization parameters strongly depend on the region and the spatial scale of interest. For instance, a substantially different regularization is recommended for the best global estimates of mass anomalies, for the best estimates of mass anomalies with Greenland only (pointwise), and for the best estimates of total mass anomalies per GrIS drainage system. This suggests that an optimal estimate of mass anomalies produced by a regularized least-squares adjustment tailored for a particular application is, in general, superior to an off-the-shelf mascon-type data product.Second, the mass trends in 2002–2023 per drainage system and over entire Greenland are estimated from actual GRACE/GRACE-FO level-2 data products. We show, among other, that the average rate of total mass loss in Greenland in the considered time interval is of the order of 270 Gt/yr. Furthermore, we analyze the factors that affect the estimated trends and quantify the uncertainties of the obtained estimates. 
Optimal positioning of two deep ocean bottom pressure gauges for tsunami wave detection in the western Ionian Sea
Authors: Romano Fabrizio , Lorito Stefano , Piatanesi Alessio , Volpe Manuela , Bayraktar Hafize Basak , Kalligeris Nikos , Amato Alessandro
Published: March 2024

Tsunami warning and forecasting largely benefit from using offshore bottom pressure gauges (OBPG); these sensors, installed far offshore and typically close to causative sources, can measure the tsunami waves before reaching the coasts to maximize the lead time for alerting. Most of these sensors are installed around the Pacific Ring of Fire (e.g., DART buoys, S-NET), which hosts ~90% of the global seismicity and most significant tsunamigenic earthquakes. Even though less frequent than in the Pacific Ocean, tsunamigenic earthquakes can also occur in the Mediterranean Sea (e.g., the M8+ 365 AD in Crete or the M7 2020 Samos earthquakes), in which the Ionian Sea is characterized by relatively high tsunami hazard (Basili et al., 2021). However, offshore sensors are not present in the Mediterranean Sea and the Tsunami Service Providers operating in the basin (CAT-INGV for Italy, NOA for Greece, KOERI for Türkiye, and CENALT for France) can rely for the tsunami monitoring activities only on the coastal tide gauges networks. One of the objectives of the Italian MEET project (MONITORING EARTH'S EVOLUTION AND TECTONICS), in the framework of the National Recovery and Resilience Plan (PNRR) funded by EU, is the deployment of two OBPGs offshore the Italian coasts. To maximize the lead time gain and due to the high cost of the instruments (including both the maintenance and installation), a careful analysis of the optimal locations where to deploy these instruments is required.Here, we present the results of the study carried out to identify the more suitable locations to deploy two OBPGs offshore the Ionian coasts of southern Italy. The method proposed considers an ensemble composed of more than 150k scenarios selected from the NEAMTHM18 source model; these scenarios are the ones capable of causing at least a 20 cm tsunami height in front of the Ionian coasts of Italy. For each scenario, we compute i) the tsunami detection times for each point within a target area (i.e., more than 200 possible locations) where the OBPG deployment is envisaged, and ii) the tsunami detection times at all tide-gauges on the coasts of the Ionian Sea. The optimal location for the two OBPGs is established by minimizing a cost function which is a summation of the minimum travel times, for each potential tsunami source, to all available existing coastal gauges and all the potential pairs of OBPGs, weighted by the rate of occurrence of each individual source according to NEAMTHM18. Basili et al. (2021). The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18). Front. Earth Sci. 8:616594, doi: 10.3389/feart.2020.616594
The 2021 paroxysmal events at Mt. Etna: Modelling of SO2 and volcanic ash dispersion by using WRF-Chem model
Authors: Semprebello Agostino , Salerno Giuseppe , Gattuso Alessandro , Sellitto Pasquale , Caccamo Maria Teresa , Longo Manfredi , Magazù Salvatore
Published: March 2024

From 18 January to 23 October 2021, 58 paroxysmal events occurred at Mt. Etna volcano by the South East Crater (SEC). Three events, that occurred on 4, 12 March and 24 June, were selected to be studied through a plume dispersion modelling approach. All the selected paroxysms generated ash-SO2 rich plumes ranging from 6 to 8.5 km above the main vent.In this work, we explored the spatial dispersion of the volcanic SO2 plume in each paroxysmal event by using the Weather Research and Forecasting Chemistry (WRF-Chem) model coupled with the time-variable ground-based SO2 flux emission data recorded by FLAME (FLux Automatic MEausurement) scanning spectrometers network managed by INGV-OE (Osservatorio Etneo). In this context, WRF-Chem was specially configured to run with variable Eruption Source Parameters (ESPs), reading at each integration time-step experimentally measured SO2 flux values.The SO2 maps resulting from the WRF-Chem simulations were compared with the dispersion pattern detected by TROPOMI sensor onboard Sentinel-5p satellite, in order to validate the capability of the model in reproducing the volcanic plume dispersion. The comparison for each simulation highlights a very good agreement between simulated data and those observed by the satellite.The ash transport was also modelled in each simulation, considering an ash Mass Eruption Rate (MER) which was inverted from the plume height. The spatial evolution of the ash patterns was compared with data retrieved from the MGS-SEVIRI satellite. The comparison shows a good agreement between simulated and observed maps. Particularly for the 12 March event, the ash comparison clearly shows that the WRF-Chem model was able to well reproduce the eastward path of the ash cloud, even at long distances, as the simulated plume reached Greece about 10 hours after the paroxysm, in agreement with satellite observations.In conclusion, the obtained results testify that the WRF-Chem model can efficiently reproduce the dispersion of both SO2 and ash plume emitted from Mt. Etna volcano over the Mediterranean basin, representing a powerful tool for assessing air quality, flying security and other hazard factors due to volcanic plume transport and deposition from local to Mediterranean scale. In addition, the performed simulations highlighted that the ground-based data measured by the FLAME network play a key role in improving the accuracy in simulating the SO2 dispersion pattern as it allows us to take into account the fluctuating and not stationary nature of volcanic plume emissions.
A low-cost multi-sensor platform for monitoring real-time hydrological and biogeochemical dynamics across land-stream interfaces
Authors: Gómez Gener Lluís , Wiedmer Antoine , Camarero Galindo Lluís
Published: March 2024

The recognition of global change impacts on catchments and the waters they drain emphasizes the need to better understand and predict both hydrological and biogeochemical dynamics at the terrestrial-aquatic interface. To achieve this great endeavor, a key priority is to substantially increase the number of multi-annual time series, covering a broad range of river types and filling existing geographical gaps (e.g., low-income regions in/and remote areas). However, commercial multi-sensor solutions are not affordable to everyone. The multi-sensor platform consists of a STM32 micro-controller board combined with a data logger module, and a set of sensors to measure hydro-chemical properties both at different depths in soils (adjacent to the streams) as well as within streams: temperature, water level, moisture, electrical conductivity, turbidity, dissolved O2 and CO2. The monitoring system is also equipped with a wireless communication capability using LoRa network technologies. To make our project as accessible as possible, we have designed, built, and programmed the multi-sensor adopting the Open Source Hardware and Software philosophy. Through the complete processes of pre-calibration and in situ measurement, the preliminary results illustrate that the proposed multi-sensor system can provide long-term, high-frequency hydrological and biogeochemical data across land-stream interfaces while keeping the balance of costs and accuracy.
Rethinking the Intertwined Biosphere
Authors: Kaandorp Chelsea , Rocha Juan , Wang-Erlandsson Lan , Flores Cynthia , Hattle Andrew , Österblom Henrik , Folke Carl
Published: March 2024

Transformations towards sustainable futures can only be achieved with an advanced understanding of how human life is intertwined with the whole biosphere. Systems of people and nature are not separate entities but inherently connected across temporal and spatial scales. There is a dynamic interplay between the biosphere and the broader Earth system. Life in the biosphere has evolved with the basic building blocks of planet Earth, like water, carbon, nitrogen, and other biogeochemical cycles. Social conditions, such as health, culture, democracy, power, justice, equity, matters of security, and even survival, are interwoven with the Earth system and its biosphere resulting in a complex interplay of local, regional, and global interactions and dependencies.In “The Intertwined Biosphere” project at the Anthropocene Laboratory, we explore empirical evidence of biosphere-Earth system dynamics since deep time and synthesise insights that can foster radical changes towards recognising humanity’s embeddedness in the world. By doing so, we aim to contribute to narratives that bridge human-nature dialectics to foster a deeper understanding of the critical interplay of humans as part of the living biosphere. In this presentation, we share our preliminary conceptual model of the biosphere as intertwined. We invite you to discuss human embeddedness in the biosphere and new directions for guiding human actions in the Anthropocene. What are the ontological and epistemological implications of understanding the Anthropocene biosphere as intertwined complex human-nature entanglements? How to study how life shapes its own living conditions?  
Novel developments in automated ice sheet mass balance measurements
Authors: Ahlstrøm Andreas P. , Fausto Robert S. , Box Jason E. , Karlsson Nanna B. , How Penelope R. , Vandecrux Baptiste , Rutishauser Anja , Lund Mads C. , Colgan William T. , Messerli Alexandra , Solgaard Anne M. , Langley Kirsty , Nielsen Rasmus B. , Andersen Signe B. , Svendsen Synne H. , Jakobsen Jakob , Petersen Allan Ø. , Shields Christopher L. ,   GC-Net team
Published: March 2024

The rapid demise of ice sheets and glaciers worldwide has increased the need for mass balance observations at a temporal and spatial resolution, where they can both help us understand the physical processes and also serve as validation or calibration for remote sensing data products or regional climate model output. Here we present the latest developments in measuring crucial components of the surface mass balance at automatic weather stations, including snow water equivalent, snow height in the vicinity of the station, sufficiently accurate transmitted position and elevation of the station, snow compaction and non-stake ice sheet ablation.Immediate access to the observations is key to certain applications, such as numerical weather forecasts. Hence, we also present the complications of providing near real-time data transmission and quality-checking as well as obstacles to a wider distribution on the WMO Global Telecommunication System (GTS).
The contribution of pore fluid pressure to earthquakes induced in St. Gallen geothermal field, Switzerland
Authors: De Matteis Raffaella , Massa Bruno , Adinolfi Guido Maria , Amoroso Ortensia , Terakawa Toshiko , Convertito Vincenzo
Published: March 2024

In July 2013, a sequence of more than 340 earthquakes was induced during the deep geothermal drilling project close to the city of St. Gallen in Switzerland. Induced seismicity represents a disadvantage during sub-surface geoenergy operations, so understanding the underlying triggering mechanisms is crucial for mitigating the seismic hazard.  To this end, we investigate the role of fluids and elastic stress transfer as driving mechanisms of the St. Gallen seismic sequence. Following the underlying idea of the Focal Mechanism Tomography technique, we estimate the excess pore fluid pressure at the hypocenters of earthquakes from the analysis of their focal mechanisms. The uncertainties on the focal mechanism parameters, friction coefficient and rock density are taken into account using a Monte Carlo approach to calculate the effect on the estimated excess pore pressure. The results indicate that, in addition to Coulomb static stress change, high-pressure fluids had a primary role in the earthquake triggering. Unlike what is observed in other geothermal fields, the value of the calculated excess pore fluid pressure is higher than the injection pressure for approximately half of the earthquakes. This can likely be attributed to the accidental release of overpressured gas (gas kick) that occurred during field operations when the seal to a gas reservoir was broken. This work has been supported by PRIN-2017 MATISSE project (No. 20177EPPN2), funded by Italian Ministry of Education and Research. 
CH4 emissions from a marine aggregate extraction site offshore Sylt (eastern North Sea, Germany)
Authors: Schmidt Martina , Reith Sarah , Bussmann Ingeborg , Schroll Moritz , Palzer Annika , Sander Lasse , Couret Cedric , Wietzel Julia , Polag Danieal , Keppler Frank
Published: March 2024

CH4 emission from coastal regions contribute with up to 1 % to the global CH4 budget but show large uncertainties in terms of spatial resolution and temporal variability. In-situ measurements of CH4 and CO2 in ambient air are carried out by the German Federal Environment Agency (UBA) at the coastal station Westerland (Sylt, Germany). High-resolution CH4 data from 2022, with a temporal resolution of several seconds, show CH4 spikes of up to 400 ppb above background. These spikes occurred under west wind conditions (marine air from the North Sea) during low tide and mainly in summer.Beach nourishment at the west coast of Sylt have been regularly carried out since 1984. From April to October, dredging vessels extract a mixture of sand and water from the seafloor of a spatially confined area (Westerland II), located 8 km off the coast and transport it to the beach and foreshore on the west coast of Sylt. To investigate the relation between sand dredging and the observed atmospheric CH4 spikes, continuous measurements of dissolved and atmospheric CH4 concentrations, were conducted on board of RV “Mya II” (AWI) from Sylt along the coast to the dredging site Westerland II. In addition, water samples were taken at different depths to determine dissolved CH4 concentrations and isotopic signatures.Near the dredging area, we observed elevated CH4 concentrations in ambient air (400-500 ppb above background) and in surface and bottom waters (80 – 100 nmol/L). The saturation of dissolved CH4 in surface waters ranged from around 100% in the control area to up to 3600% in the dredging area. Depending on the wind strength this resulted in a diffusive flux of 48 ± 47 µmol m2 d-1 in the dredging area, in contrast to a diffusive flux of 25 ± 30 µmol m2 d-1 in the control area. Taking the severe storm just before our cruise which should have led to a strong degassing of the whole area into account, the dredging seems to be a strong point source for dissolved CH4.Our measurements clearly confirmed elevated concentrations and fluxes of CH4, both in the atmosphere and the water column above the sand dredging site, compared to the surrounding areas. Moreover, dissolved CH4 within the dredging site was characterized by more negative stable carbon and hydrogen values compared to outside Westerland II, indicating a microbial origin of the excess CH4 there.
Tectonic inversion in the Bandar Jissah Area: evidence for Cenozoic contraction in northern Oman
Authors: Bailey Christopher , Driscoll Eran
Published: March 2024

The geology of northern Oman and eastern Arabia is distinctive because of the emplacement of the Semail Ophiolite onto the stable Arabia platform in the late Cretaceous followed by the later development of the Jebal Akhdar and Saih Haitat domes. East of Muscat, the Wadi Kabir Fault forms an important structure along which the northern edge of the Saih Hatat domes was unroofed.  In the Bandar Jissah area, Triassic carbonates occur in the footwall of the NNE-dipping Wadi Kabir Fault while rocks of the Semail Ophiolite, newly discovered rocks of the metamorphic sole, and a sequence of Paleogene sedimentary rocks crop out in the footwall.  Some workers posit that the Wadi Kabir and associated faults form basin-bounding faults for the Bandar Jissah rift basin and that folds in the hanging wall cover sequence are the product of rollover during basin formation.However, our detailed mapping and kinematic analysis illustrates that folds in the hanging wall are actually contractional structures that formed due to tectonic inversion along the Wadi Kabir and other faults.  The overall shortening is modest (~10%) and primarily confined to the hanging wall rocks, consistent with buttressing against mechanically rigid rocks in the footwall of the Wadi Kabir Fault.  These structures require an interval of N-S directed shortening in northern Oman  that post-dates the deposition of mid-Eocene marine sediments in the Seeb Formation. The Wadi Kabir Fault also has localized zones of listwaenite preserved in its damage zone derived from ophiolitic rocks. Collectively, the Wadi Kabir Fault is a long-lived structure that’s experience multiple episodes of extensional and contractional slip since the Paleocene.
Disentangling the forced and unforced components of observed surface air temperature trends
Authors: Aru Hasi , Li Chao , Olonscheck Dirk
Published: March 2024

Global mean surface air temperature stands is a critical indicator for gauging climate change, both on contemporary and over centennial scales. Previous studies on surface air temperature (SAT) variations tend to emphasize the uncertainties in model-simulated global warming projections, instead of differentiating the observed SAT trend patterns. Our study aims to partition observed SAT trends into forced and unforced components on decadal to multidecadal scales. Utilizing historical simulations from the ensemble mean of six large ensemble models from the Coupled Model Intercomparison Project Phase 6 (CMIP6), we develop a regression model specifically designed to robustly detect and attribute trends in the observed SAT. We evaluate the models' capability to replicate the detected forced SAT trends. Our findings indicate that external forcings are a significant driver of  SAT trend patterns on multidecadal scales, with pronounced warmingtrends over the Eurasian and North American continents. Conversely, on decadal scales, the forced SAT trends are not as evident within the observational data. Our results also underscore the limitations of current state-of-the-art climate models in capturing decadal trend variability. Interestingly, when comparing high- to low-sensitivity climates—those with high (ECS > 4.5K) versus low (ECS < 4.5K) equilibrium climate sensitivity—we find the high-sensitivity models to underrepresent the unforced signals of observed SAT trends. By leveraging significant observational data that captures the forced trend patterns on multidecadal timescales, we could enhance and constrain the future projection of SAT trends and variability more effectively.
Rapid flood mapping: Fusion of Synthetic Aperture Radar flood extents with flood hazard maps
Authors: Khadka Ambika , Anders Annett , Millinship Ian
Published: March 2024

Rigorous flood monitoring by ICEYE is enabled by the large-scale and systematic availability of synthetic aperture radar (SAR) data from the satellite constellation deployed and operated by ICEYE [1, 2]. However, in dense urban areas and under tree canopy cover, using single X-band based SAR images directly for rapid flood detection inherits large uncertainties due to its complex backscattering mechanisms. This study addresses this gap by proposing an approach to rapidly detect flooding in urban areas by merging real-time SAR flood extents from surrounding rural areas with hydrodynamically modeled flood hazard maps. If a flood is fully contained within an urban area, other auxiliary flood evidences are merged with JBA’s high resolution global flood hazard maps at 5 and 30m resolution.  The precomputed simulation library approach used in Mason et al. 2021 appeared as a challenge, as floods are dynamic in nature [3], they suggested the benefits of using assimilation to integrate SAR data and model outputs in dynamic situations. Thus, the proposed approach builds upon Mason et al. 2021[3] and the framework for improved near real-time flood mapping [2], wherein SAR data is assimilated to enhance future flood predictions and improve the quality of flood hazard maps. This process, in turn, enhances further real-time rapid flood mapping aiding governments, NGOs and disaster responder to make accurate timely decisions in the immediate aftermath of an event.  References:[1] Dupeyrat, A., Almaksour, A., Vinholi, J., and Friberg, T.: Deep learning for automatic flood mapping from high resolution SAR images, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-6790, https://doi.org/10.5194/egusphere-egu23-6790, 2023.[2] Friberg, T., Khadka, A., and Dupeyrat, A.: A framework for improved near real-time flood mapping, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8520, https://doi.org/10.5194/egusphere-egu23-8520, 2023.[3] Mason, D.C., Bevington, J., Dance, S.L., Revilla-Romero, B., Smith, R., Vetra-Carvalho, S., Cloke, H.L.: Improving Urban Flood Mapping by Merging Synthetic Aperture Radar-Derived Flood Footprints with Flood Hazard Maps, Water 2021, 13, 1577, https://doi.org/10.3390/w13111577
Evaluation of the wall friction angle of dry volcanic materials from laboratory experiments.
Authors: Rucco Ilaria , Dioguardi Fabio , Di Vito Mauro Antonio , Nedumpallile-Vasu Nikhil , Sarocchi Damiano , Ocone Raffaella
Published: March 2024

Granular materials are widely involved in several processes, from the food, cosmetic, and pharmaceutical industries to natural phenomena such as pyroclastic density currents and landslides. Therefore, the study and understanding of their behaviour and rheology are of paramount importance in terms of hazard assessment and for developing and implementing mathematical and numerical models. The simulations try to reproduce the complexity of the flows taking into account several parameters, but, despite the advances in the theoretical descriptions of granular flows, a gap still exists between the empirical models and the experimental observations.In this work, we present the results of the characterization of volcanic samples carried out with the FT4 Powder Rheometer (Freeman Technology). Shear tests, compressibility tests, and wall friction tests were performed to characterize the flowability of the powders. We particularly focus on the wall (or basal) friction angle, which describes the interaction of the particles with a variable-roughness substrate. Some glass beads have also been investigated, as a reference value. The results show how the ratio between the roughness of the surface and the average particle size of the samples influences the wall friction angle. Moreover, the comparison with the glass beads also reveals the influence of the irregular shape of the particles.
Multi-decade evaluation of the UK’s greenhouse gas emissions
Authors: Rigby Matthew , Manning Alistair , O'Doherty Simon , Stanley Kieran , Ganesan Anita , Pitt Joe , Rennick Chris , Safi Emmal , Arnold Tim
Published: March 2024

Top-down evaluation of the UK’s methane, nitrous oxide and halogenated greenhouse gas emissions has been possible since the 1990s, firstly due to measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE), combined later with the UK national-scale Deriving Emissions linked to Climate Change (UK DECC) network. Here, we show that carbon dioxide-equivalent emissions inferred from observations of these gases have declined more slowly than stated in the UK’s National Inventory Report (NIR); a decline of approximately 50 Tg/yr CO2-e is found between 1990 and 2021, compared to approximately 100 Tg/yr CO2-e in the inventory. This difference, which is driven largely by a smaller-than-reported reduction in methane emissions, suggests that the UK may be approximately 3 years behind its stated progress toward net-zero. This paper will describe the evolution of greenhouse gas monitoring in the UK, including an overview of the first decade of national-scale emissions estimation from the UK DECC network. It will show how top-down emissions are calculated, and how atmospheric observation-based estimates are used, in close collaboration with inventory teams, to improve the national inventory. Finally, it will discuss the UK’s plans for a prototype “operational” emissions evaluation system, the Greenhouse gas Emissions Measurement and Modelling Advancement (GEMMA).
ALERTA CO2: An alert system to monitor and mitigate the hazard associated with high concentrations of indoor and outdoor air CO2 at the inhabited areas of Puerto Naos and La Bombilla, La Palma
Authors: Padilla Germán D. , Pérez Nemesio M. , López Carmen , López Rubén , Hernández Pedro A. , Moure David , D'Auria Luca , Torres Pedro , Barrancos José , Melián Gladys V. , D'Nardo Daniel , González Alexis M. , Álvarez Antonio
Published: March 2024

Anomalous CO2 degassing were observed by the end of November 2021 in the neighborhoods of La Bombilla and Puerto Naos, and some banana plantations, located at the North-West flank of Cumbre Vieja volcano ridge, La Palma island, at about 6 km distance southwestern of the 2021 Tajogaite eruption vents. These urban areas, not directly damaged by lava flows, were included in the exclusion zone due to the strong volcanic-hydrothermal carbon dioxide emissions (CO2>5-20%). CO2 is an invisible toxic gas, as well as asphyxiant gas, and may be lethal when is present in concentrations higher than 14V%.During the last two years, several institutions deployed indoor and outdoor own gas networks, to try to delimitate the CO2 anomalies where CO2 air concentration exceed hazardous thresholds, but with an insufficient number of CO2 sensors (less than 100) to cover all homes, garages, basements and stores in real time. These studies aim to understand the dynamics of CO2 emission to delimitate the CO2 anomalies where CO2 air concentration exceed the hazardous thresholds, and help the authorities’ decision-making of people's return to their homes and stores.The ALERTACO2 project was born with the objective of implementing a much more extensive network of CO2 sensors (1,200) sensors in most of the building of both inhabited areas, the creation of a 24-hour monitoring room and an information and awareness campaign for the population about this volcanic hazard. The financing (3M EUROS) comes from the Spanish Government, and has the participation of the National Geographic Institute (IGN) and the Volcanological Institute of the Canary Islands (INVOLCAN).Each sensor has a color light code to indicate the CO2 concentration (green, yellow, orange and blue if the sensor is not working), and a QR code to view the information remotely. So far 35% of the 1,200 sensors have been installed inside and outside homes of both urban areas (including beaches and Sol Melia Hotel). Each sensor sends the data to the 24-hour monitoring room via a gateway installed at the roof of each building. Thanks to the project, some families in the area marked green have been able to return to their homes in safety conditions in December 2023 since their homes CO2 concentrations were below 1,000 ppm.
Machine learning for volcano deformation using InSAR: moving beyond detection and classification to forecasting
Authors: Hooper Andrew , Gaddes Matthew , Novoa Camila , Lazecky Milan , Shen Lin , Bilsland Rachel , O'Grady Eilish , Sepulveda Josefa , Ebmeier Susanna , Hogg David , Maghsoudi Yasser , Rigby Richard , Biggs Juliet
Published: March 2024

Ground deformation is a key indicator of volcanic activity and routine acquisition by the Sentinel-1 satellite mission now allows us to monitor volcano deformation globally. We have developed a system to routinely apply radar interferometry (InSAR), whenever a new Sentinel-1 image is acquired, and extract the deformation. As there are too many images to inspect individually, we have developed an automated machine-learning approach, based on independent component analysis, to identify new deformation patterns and also any changes in rate of existing deformation patterns, both of which are key indicators of changes in activity. In addition, we have developed a deep-learning based algorithm to classify the potential source of the deformation.
Our current goal is to forecast how a volcano might deform in the future, based on a time series of interferograms up to the present day. To this end, we have tested various deep-learning algorithms from the field of video prediction. Training of these networks requires a large data set of deformation time series so, in addition to processing all available SAR data acquired over volcanoes, we are simulating data using physical models of various deformation processes that can occur at volcanoes. 
We aim for our forecasts to be a useful tool for volcano observatories and we also expect the resulting forecasts to highlight common deformation sequences operating at volcanoes, leading to deeper understanding of the underlying processes. Already, characterising how deformation develops in time, has led us to new discoveries about generalisable underlying processes operating at volcanoes undergoing uplift.
Local-scale analysis on sea-ice deformation based on radar imagery and deep learning
Authors: Uusinoka Matias , Polojärvi Arttu , Haapala Jari
Published: March 2024

Sea-ice deformation is commonly estimated from satellite imagery in low spatial and temporal resolutions. This coincides with the fact that the lower bound of scale invariance in ice deformation is analytically estimated at the scale of ice thickness. Estimating deformation patterns from more accurate buoy records can in turn be problematic due to their sparse spatial coverage while the previous analysis of radar imagery has been disturbed noisy data. In response to the gap in high resolution empirical data, we deploy a novel deep neural network-based motion tracking method with ice-radar imagery gathered continuously during MOSAiC expedition for statistical analysis of sea ice deformation. The proposed method enables estimating ice dynamics at length scales down to 10 meters at a 10-minute temporal scale in a 10 km ×10 km domain. Overcoming issues with high-frequency noise in radar data, we output ~10^8 daily deformation-rate estimates with accuracy comparable or higher than those gained by using ice buoys. The method allows quantification of the highly intermittent and localized deformation and, thus, the analysis of established scaling laws at resolutions never analyzed before. In light of the changing ice conditions in the Arctic, we emphasize seasonal variability and separation between ice zones.
Simulating the impact of Antarctic subglacial hydrology on ice sheet evolution
Authors: Gladstone Rupert , Zhao Chen , Zwinger Thomas , Cook Samuel , Wang Yu , Gwyther David , Werder Mauro , Moore John
Published: March 2024

While the slow moving interior of the Antarctic Ice Sheet is not prone to rapid change, the fast flowing outlet glaciers may exhibit accelerations and unstable retreat in response to ocean induced melting of the ice shelves. This rapid motion is only possible due to sliding of ice over the bed, motion which is dependent on the presence, and pressure, of liquid water under the ice sheet.  This subglacial hydrologic system is fed by in-situ melting caused mainly by friction heat as ice slides over the bed, and its outflow feeds into ice shelf cavities across deep grounding lines.  Two-way interactions between ice dynamics and the hydrologic system may occur due to changing sliding speeds, subsequent meltwater generation, and the responding changes in basal water pressure, which in turn impact on sliding resistance.  The subglacial water system may also impact on ice shelf cavity circulation due to its very low density relative to ocean water, and this may also impact indirectly on ice dynamics due to the changing cavity circulation driving changing ice shelf melt rates, which affect ice shelf thickness and therefore backstress. The current generation of ice sheet models used in sea level prediction do not represent the evolution of the subglacial hydrologic system.  A typical approach is to spatially tune a sliding parameter in which all aspects of basal physics relating to sliding and hydrology are implicitly hidden.  We will outline a modelling approach to incorporate the GLAcier Drainage System (GlaDS) model into a coupled system in which the hydrologic system can interact with both ice dynamics and cavity circulation. Ice dynamic model Elmer/Ice and the Regional Ocean Modelling System (ROMS) will be used, coupled through the Framework for Ice Sheet - Ocean Coupling (FISOC).  GlaDS represents the subglacial hydrologic system as two interacting components: a distributed network of linked cavities and a network of channels.  We will show preliminary simulations of these linked cavities and channels from Antarctic simulations. We will outline a plan for moving towards fully coupling GlaDS to the ice dynamics and ice shelf cavities, along with an "accelerated forcing" approach to handle asynchronicities.