bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact Predictability: Exploring Extremes in Biosphere Dynamics with Recurrent Neural Networks
Authors: Martinuzzi Francesco , Mahecha Miguel D. , Camps-Valls Gustau , Montero David , Williams Tristan , Mora Karin
Published: March 2024

Understanding Earth's terrestrial biosphere dynamics is vital for comprehending our planet's environmental health and sustainability. Recently, the frequency and intensity of extreme climate events have risen, significantly impacting the biosphere. Given the advancements of recurrent neural networks in modeling complex, nonlinear dynamics, we explore the capability of recurrent neural network models to model and predict the impacts of extreme events on biosphere dynamics. In this work, we compare four different recurrent network architectures, each with distinct features: 1) Recurrent Neural Networks (RNNs); 2) Long Short-Term Memory-based networks (LSTMs), known for their efficacy in handling long-term dependencies; 3) Gated Recurrent Unit-based networks (GRUs), which offer a simplified yet effective alternative to LSTMs; and 4) Echo State Networks (ESNs), which are distinguished by fixed internal weights and training based on simple linear regression. Our study found that while recurrent network architectures show similar performance under standard conditions, Echo State Networks (ESNs) show slightly superior performance, particularly under extreme events. However, we also identify limitations in current models under extreme conditions, underscoring the need for specialized approaches to enhance predictive accuracy in these circumstances.
Experimental study of viscoplastic surges down complex topographies and comparisons with numerical simulations.
Authors: Ginot Colin , Chambon Guillaume , Wallon Maxime , Vigneaux Paul , Philippe Pierre
Published: March 2024

In a context of climate change, sediment availability and occurrence of heavy rainfall episodes are tending to increase, resulting in a likely rise in frequency and magnitude of debris flows. For effective hazard management, predicting the velocity, depth, and run-out of these flows in realistic settings, while considering all relevant processes, is crucial. In particular, as debris flows may exhibit viscoplastic characteristics, a better understanding of the interplay between inertia, rheology and topographical features is necessary. We report on well-controlled laboratory experiments of viscoplastic surges flowing down a model topography. A volume of viscoplastic fluid (Carbopol) is released onto four 3D-printed topographies featuring different patterns of mounds and ridge. Using Moiré projection, we monitor flow depth with a temporal resolution of 250 Hz, exploring a wide range of configurations involving varying volumes and fluid rheological properties. This set-up enables us to investigate the front velocity, the deviation and accumulation of fluid induced by the obstacles and the shape of the deposit. Two distinct flow regimes are observed. Initially, a rapid regime develops with a high front velocity, and the fluid spreads in both transversal and longitudinal directions. This regime is driven mainly by inertial forces. Subsequently, the front velocity drops drastically and the fluid flows mainly along the slope. In this second regime, controlled by rheological effects, the flow is strongly influenced by the topography with various mechanisms depending on the case (deceleration, accumulation, channelization, etc.). These experimental results are then systematically compared with depth-averaged numerical simulations based on shallow-water hypothesis. We compare the outcomes of two models implementing different representations of the complex rheology. The experimental data serves as a benchmark to assess the predicting capabilities of the models and evaluate the resulting uncertainties. These findings offer new insights into the physical processes driving debris flows, and they will ultimately contribute to the enhancement of simulation tools used in hazard management.
Exploring the impact of frictional heterogeneities on the seismic cycle: Insights from laboratory experiments
Authors: Noël Corentin , Dublanchet Pierre , Passelègue François
Published: March 2024

Deformation within the upper crust is mainly accommodated through slip on fault systems. These systems can accommodate slip via different modes, going from aseismic creep (i.e., stable motion) to dynamic earthquake (i.e., unstable motion). Notably, a single fault is not confined to a specific slip mode, as recent geodetic observations have indicated that a single fault can exhibit both stable and unstable motions. The distinct slip behaviours have been attributed to fault spatial heterogeneity of the frictional properties, rheological transitions, or geometrical fault complexities.To comprehensively characterize the impact of frictional heterogeneities, we deformed heterogeneous fault samples in a triaxial apparatus, at confining pressure ranging from 30 to 90 MPa. The fault planes, sawcut at a 30° angle from the sample axis, consisted of two materials: granite and marble. Experiments were conducted for both marble asperities embedded in granite and vice versa, alongside homogeneous fault samples of single lithology. The selection of granite and marble was based on their different mechanical and frictional characteristics, with granite exhibiting seismic behaviour, while marble demonstrated aseismic behaviour across the pressure range tested.Our findings reveal that the stress drops of seismic events are dependent on fault composition, with faults containing higher granite content exhibiting larger seismic events. In addition, by coupling the inversion of the kinematic slip from strain-gauge measurements and the records of acoustic activity during experiments, we demonstrate that the nucleation and propagation of seismic events are significantly influenced by lithological heterogeneity on the fault plane. In the case of homogeneous faults, the seismic event nucleation is relatively straightforward, initiating in the highest stressed region and propagating uniformly. Conversely, heterogeneous faults display more intricate nucleation patterns, often featuring multiple nucleation regions converging into a major dynamic event. The dynamic event propagation is expedited when traversing granite areas and more restrained within the marble. Remarkably, our experiments demonstrate that heterogeneities are required in order to induce earthquake afterslip. These results emphasize the crucial role of fault heterogeneity in earthquake nucleation and propagation, highlighting that even minor lithological heterogeneities are sufficient to complicate laboratory earthquake dynamics.
Field scale optimization of woodchip bioreactors for nitrate removal from drainage water in the Netherlands
Authors: Jansen Stefan , Van Driezum Inge , Rozemeijer Joachim , Van Loon Arnaut , Van Herpen Frank
Published: March 2024

It is known from recent international research that woodchip bioreactors can be an effective measure to reduce emissions of nitrate from agricultural drainage water. In the Netherlands, up till now no experience was present with woodchip bioreactors. Therefore, a field pilot was started at an agricultural test location situated in a lowland catchment in the south of the Netherlands (Vredepeel). A woodchip bioreactor was installed to treat drainage water from 4 ha arable land on sandy soil. Nitrate was measured in the in- and effluent of the bioreactor to estimate nitrate removal efficiency over time. Also, water chemistry and discharge were monitored. With a series of sampling points in the woodchip bioreactor, biogeochemical processes in the reactor are investigated that can explain the performance of the reactor. The goal is to not only determine the removal efficiency, but also potential side effects and effects of temporarily limited flow rate (e.g. sulfide and ammonia production and oxygen demand). We aim to give practical guidelines for practical design and application for agricultural fields in sandy lowland catchments. In this contribution we will present the monitoring results of one drainage season.
Analyzing anthropogenic impact on river morphodynamics in the Upper Orcia Valley (central italy) through multitemporal NDVI assessment
Authors: Sannino Annalisa , Vergari Francesca , Iacobucci Giulia , Del Monte Maurizio
Published: March 2024

Mediterranean environments are significantly shaped by human activities, and the morphology of rivers often reflects centuries of human intervention for land development. Previous studies, spanning decades, have highlighted the drastic river adjustments in the Italian landscape. These adjustments often reflect the man-induced land use changes within the drainage basin. The analysis of the rivers in Tuscany site (central Italy), has revealed profound changes, especially in terms of channel bed narrowing and incision. This work present the fluvial system scale analysis of the anthropogenic impact in the Upper Orcia Valley (southern Tuscany), that undergone a huge land reclamation, as evidenced by the archives of the Land Reclamation Authority, established in 1929. Accelerated erosion landforms, such as calanchi and biancane badlands, have been extensively reduced by this intervention. Consequently, a multitemporal analysis indicates a decreasing trend in erosion rates over the recent decades, accompanied by an increase in agricultural and forested areas and a narrowing of river channels. To comprehend the role of land cover and land use changes in river dynamics, the results of a multitemporal geomorphological survey and an analysis of land use changes were compared with spatio-temporal computation and analysis of the NDVI (Normalized Difference Vegetation Index), commonly used in ecology to gauge the impact of green biomass on soil erosion. NDVI was computed using Landsat and Sentinel multispectral imagery (Landsat 1-2-4-5-8 and Sentinel-2), selecting images acquired every 5 years in May, corresponding to the Start of Seasons (SOS) month, within the 1975-2021 timeframe. The results revealed a general decrease in bare lands and a significant increase in dense vegetation cover. The overlap this data with multitemporal geomorphological mapping demonstrated a recolonization by forests along main riverbeds and in badland areas, indicating a reduction in sediment supply from hillslopes, possibly causing the observed channel narrowing and incision trends along main rivers. These findings can be attributed to increased land use for agriculture, artificial reforestation, and the gradual abandonment of rural areas, leading to the recent reconquest of broad-leaved forests.
A new formulation for source parameters estimation from DAS native strain data.
Authors: Strumia Claudio , Trabattoni Alister , Supino Mariano , Baillet Marie , Rivet Diane , Festa Gaetano
Published: March 2024

Distributed Acoustic Sensing (DAS) is establishing as a promising technique in Seismology. This novel system turns a fibre optic cable into a continuous single component array with very dense spatial sampling. Simplicity of installation and availability of telecommunication cables (dark fibres) make the technique very advantageous for investigating harsh environments like seafloors, sensing up to hundreds of kilometres of fibre with fine spatial resolution. Given the high potential, the technology has been successfully tested in recent years for several earthquake monitoring tasks, such as location, subsurface characterization, focal mechanism determination, tomography, or source back projection. The transferability of standard seismological tools to DAS data is straightforward when working with time picking, while analysis of the amplitude content of the signal demands further research. This is the case of earthquake source characterization, where standard approaches require conversion of strain rate data into more classical kinematic quantities (i.e. acceleration or velocity). In this work we develop a new formulation that allows to estimate source parameters without the need for conversion. We start from the description of the far-field strain radiation emitted from a circular seismic rupture, showing that the time integral of the strain is related to the Source Time Function. Using this quantity, we develop the spectral modelling allowing for frequency domain inversion of DAS data for estimation of moment magnitude and corner frequency. The formulation accounts for the unique azimuthal sensitivity of the cable in the radiation pattern average, and explicitly shows DAS enhanced sensitivity to slow scattered waves propagating beneath the fibre.We validated the proposed approach on two case-studies, for events in local magnitude range  0.4 - 4.3, comparing the results with estimates from standard seismic instruments. Earthquakes recorded on a 150km long cable offshore the coast of central Chile during a 1-month DAS survey exhibit scale invariant stress drops, with an average of Δσ=(0.8±0.6)MPa. Also, moment magnitude estimates agree with results from standard seismic instruments. The analysis of small magnitude events (ML
Modernising RoR Hydropower: A Study on Retrofitting Aged Turbines for Optimal Performance
Authors: Brown Solomon , Yildiz Veysel , Rougé Charles
Published: March 2024

Hydropower stands out as an economical, reliable, sustainable, and renewable source of energy. It has been the leading source of renewable energy across the world, generating more than 15 % of total electricity in 2022. Therefore, it will likely play a crucial role as the energy system shifts towards a carbon-free future. The turbine system is at the heart of the hydropower plant and converts flowing water into mechanical energy. Remarkably, around 154 gigawatts, or one-fifth of the installed hydropower turbines, will be more than 55 years old by 2030 globally. Modernising these aged turbines is essential for sustaining optimal plant performance and this will create opportunities to retrofit hydropower facilities to improve their adaptability to changing hydrological conditions. A well-defined methodology is necessary to evaluate feasibility and select optimal solutions for upgrades. This study addresses this critical necessity in the context of run-of-river (RoR) hydropower plants with the HYPEROP toolbox to efficiently evaluate and choose optimal turbine replacement or upgrade options. HYPEROP provides operational optimization capabilities coupled with design flexibility and expanded simulation features for complex turbine configurations. It facilitates the selection of turbine systems featuring large and small turbines. The effectiveness of this toolbox is illustrated through the  case study of the Bonnington RoR hydropower plant, commissioned in 1927 on the upper reaches of the River Clyde in Scotland, United Kingdom. Bonnington RoR features a pair of two identical Francis turbines, each designed for a discharge of 12 m³/s and equipped with an installed capacity of 5.5 MW.Our analysis indicates that, by prioritising Net Present Value (NPV) maximisation through a single objective function and considering historical discharge records, HYPEROP offers a novel configuration featuring non-identical Francis turbines with design discharges of 16.13 and 9.13 m³/s.  Optimal design increases power production by approximately 3.4 GWh (~7 %) annually by providing operational flexibility and retaining high efficiency over a range of discharge values. The optimal design yields an NPV of approximately 3 million dollars (USD), factoring in the additional energy increase as revenue, turbine replacement cost, and lifetime operation cost. The payback period for this investment is projected to be 15 years when considering only the additional energy as revenue. It's worth highlighting that the optimised design notably outperforms the current configuration, particularly in response to variable streamflows, including both high and low flows. Therefore, optimal design is expected to be less vulnerable to climate change due to higher efficient configuration. 
Joint inversion of P-wave receiver function and surface wave dispersion data based on deep learning. 
Authors: Hu Jing
Published: March 2024

The use of P-wave receiver function and surface wave dispersion data is crucial in exploring the structure of the Earth's crust and upper mantle. Typically, to address the ambiguity resulting from using a single type of dataset for inversion, these two types of seismic data, which have different sensitivities to shear wave velocity structure, are jointly inverted to achieve a detailed velocity structure. However, methods that rely on a linearized iterative joint inversion approach depend on the initial model selection, while non-linear joint inversion frameworks based on model parameter space search are computationally intensive. To address these challenges, this study suggests employing a deep learning strategy for the joint inversion of P-wave receiver function and surface wave dispersion data. Two distinct neural networks are developed to extract features from the P-wave receiver function and surface wave dispersion data, and different loss functions are tested to train the proposed neural network. The proposed method has been applied to actual seismic data from South China, and the results are comparable to those obtained by jointly inverting body wave first travel-time, P-wave receiver function, and surface wave dispersion data.
High resolution 3-D mapping of soil organic carbon at field-scale with multi-source proximal sensing data fusion and INLA-SPDE
Authors: Ji Wenjun , Hao Ye , Li Baoguo , Yan Yang , Huang Yuanfang , Shi Zhou , Yin Jianxin , Ren Tusheng , Zhou Hu
Published: March 2024

Soil organic carbon (SOC) plays an important role in the carbon cycling of terrestrial ecosystems, and smallholder quantification of soil carbon stocks also has significant contribution to greenhouse gas emission, especially in black soil areas. The objective of this study was to evaluate a strategy for assessing soil organic carbon using 3D digital soil mapping with INLA-SPDE and proximal soil sensor data fusion, and compare it to traditional spatial interpolation with 3D-IDW. A total of 42 soil cores, with a grid sampling strategy (50 m), were collected from a 16.5 ha field in typical black soil area of the Northeast China. At each sampling location, 10 soil samples were collected from the surface down to 1m depth with a 10cm depth interval and their SOC contents were measured with standard laboratory method. The visible and near-infrared (350-2500 nm, Vis-NIR) and mid-infrared (4000-650 cm-1, MIR) spectra were collected in situ immediately after the samples were collected. At the same day, the apparent electrical conductivity (EC) and topography were measured with an EM-38 and a real-time kinematic global navigation satellite systems receiver, respectively. The 42 soil cores were split to calibration and validation set by ranking the topsoil SOC from high to low with a 3:1 ratio. Different combinations of the data from the four sensors were used as environmental covariates to model SOC in 3D with INLA-SPDE in Bayesian space stochastic simulation. By comparing the validation results to that of 3D-IDW, it was found that the map with INLA-SPDE and all ancillary predictors obtained the highest prediction accuracy with a R2 of 0.82 and RMSE of 2.10g kg-1, while the validation with 3D-IDW obtained the lowest value with a R2 of 0.42 and RMSE of 3.13g kg-1. The maps with INLA-SPDE also showed more detailed changes. By only adding the vis-NIR spectra using feature extraction, the maps generated with the INLA-SPDE could achieved acceptable accuracy (R2 = 0.76 and RMSE of 2.12g kg-1). We thus concluded that the use of 3D digital soil mapping with INLA-SPDE and proximal sensor data fusion is a promising way to assess soil organic carbon.
European and Siberian lithospheric thermo-chemical heterogeneity and density structure.
Authors: Shulgin Alexey , Artemieva Irina
Published: March 2024

We present a new combined model for the density structure of the lithospheric upper mantle beneath Europe and Siberia, based on a 3D tesseroid gravity modeling. Our results are based on the EuNaRho model (Shulgin & Artemieva, 2019) complimented by similar modeling approach for Siberia. For Siberia modeling is preformed based on a detailed crustal structural database SibCrust (Cherepanova et al., 2013) constrained by regional seismic data. The presented residual lithospheric mantle gravity anomalies are derived by removing the 3D gravitational effect of the crust. Later, these anomalies are converted to lithosphere mantle in situ densities. To evaluate chemical heterogeneities of the lithospheric mantle, thermal effects are removed based on the global continental thermal model TC1 (Artemieva, 2006). The resulting density model at SPT conditions shows a highly heterogeneous structure of the cratonic lithospheric mantle, and distinct change at the transition between different tectonic units. We speculate on the origin of these anomalies.
Late Miocene evolution of Jordan Rift Valley recorded on its eastern flank
Authors: Scardia Giancarlo , Cerqueira João Carlos , Ladeira Francisco , Parenti Fabio , Neves Walter
Published: March 2024

The Jordan Rift Valley (JRV) is a depression produced by the active Dead Sea Transform (DST), separating the Sinai subplate and the Arabian Plate. Its beginning is related to the late Miocene (~6 Ma), when sinistral displacement of the DST gained an extensional component, thus accentuating the subsidence of the JRV. This shift is recorded by Messinian basalt flows that cover JRV eastern slopes (Zerqa Ma, Mujib, and Tafila basalts; 6–3.4 Ma) and the Cover basalt (5.8–3.6 Ma) in the Galilee region. Sediments from the Sedom Lagoon since ~12 Ma suggests that the JRV was already a shallow depression connected with the Mediterranean Sea, which at the early Pliocene (5–4 Ma) lost permanently this connection due to the uplift of the JRV flanks. More information about geomorphology and drainage pattern of the region during the Late Miocene is limited to information available along the western side of the JRV, including the fluvial/lacustrine Hazeva Fm (~20–6.4 Ma) in the Arava region and lacustrine/marine formations in the lower Galilee (~17–5 Ma). Here we discuss the implications of Zarqa Valley geomorphological features and its volcano-sedimentary infill to the Miocene evolution of the JRV. The Zarqa Valley is carved into Cretaceous/Paleogene bedrocks at the Eastern Flank of the JRV, and it hosts a perennial water drainage system flowing westward to the Jordan River. The oldest dated filling of the Zarqa Valley is represented by a series of late Miocene lava flows, named collectively as “Lower Basalt” (LB), spanning 5.82 to 5.51 Ma. It records the existence of a pre-existing valley in the late Miocene, with already at least 300 m of incision, observed by the difference of the base of the LB and the bedrock summits surrounding the valley. The LB outcrops ca. 40 km east of JRV axis and its thickness increases eastward to more than 100 m. W-NW paleocurrent data in conglomerates underlying the LB indicate that the Zarqa River maintained the same flow towards the JRV since the Late Miocene. The occurrence of the LB in the Zarqa Valley is synchronous with the dramatic sea level fall of Messinian Salinity Crisis (MSC, 5.97–5.33 Ma), when the Sedom Lagoon lost temporarily the connection to the Mediterranean Sea. Opposite to what is observed throughout the Mediterranean Sea, where rivers underwent a profound incision phase, the Zarqa Valley experienced aggradation of conglomerates and thick basalt flows. We propose that this is an indication that Sedom Lagoon acted as local base level of an endorheic drainage by the time when the MSC started, possibly with an increasing water table, necessary to produce the accumulation space to account for the Zarqa Valley deposition. We hypothesize that a highstand of the base level in the JRV during the MSC can be explained by a favorable climate and several stream capture in the Levant that caused rivers to migrate to the endorheic drainage of the Sedom Lagoon.
Characteristics and mechanism of a catastrophic landslide-debris flow disaster chain triggered by extreme rainfall in Shaanxi, China
Authors: Zhan Jiewei , Yao Zhaowei
Published: March 2024

On October 5, 2021, a landslide-debris flow disaster chain occurred suddenly in Hanping village, Shaanxi Province, China. This catastrophic disaster chain damaged 7 houses, 41.9 hectares of arable land and 3 roads and resulted in 1 death. Based on a detailed field investigation of the disaster site, we analyzed the dynamic evolution of the disaster chain by using experimental analysis, unmanned aerial vehicle (UAV) photogrammetry, satellite remote sensing interpretation and the SBAS-InSAR technique and then preliminarily revealed the movement process and causal mechanism of the disaster chain. The results suggested that the first landslide initiated in the upper part of Canger cliff, which is the result of the combined effects of slope structure, earthquake damage, engineering disturbance, and rainfall infiltration. Among them, extreme rainfall events are the primary factors that induce landslides. Before the landslide, InSAR results showed that deformations had already appeared in the source area, and the deformation rate had a strong correlation with precipitation. Then, the potential-to-kinetic transformation effect and air cushion effects generated by the landslide movement in the narrow and steep section of Canger cliff led to the disintegration of the sliding body. With replenished surface runoff, the clastic flow gradually transformed into debris flow. Moreover, due to the dam-breaching effects at bayonets and bends and the entrainment effect of the high-density debris flow along the gully, the scale of debris flow increases gradually, resulting in catastrophic damage during the movement. The findings of this study provide a significant reference and guidance for understanding the chain-generation mechanism of landslide-debris flow disaster chains, as well as informing disaster prevention and mitigation strategies.
Tremor analysis on dense network using Distributed Fiber Optic Sensing at La Palma
Authors: Fontaine Olivier , Caudron Corentin , Lecocq Thomas , D'Auria Luca , Barrancos José
Published: March 2024

The fast rise of Distributed Fiber Optic Sensing (DFOS, also known as DAS) technology in seismology has enabled to reach new horizons in volcano monitoring for example by its ability to attain hardly accessible environment and its high spatial and temporal resolution. Such advantages are extremely valuable for observatories located on islands where the ocean complicates the installation of traditional seismic networks and would require deploying ocean bottom seismometers.In this research, we bring DFOS to a well-studied eruption that occurred in 2021 at La Palma (Canary Islands) by using a dark fiber, an unused telecom optic fiber, joining the islands together. The cable was interrogated using an HDAS (from Aragon Photonics) operated by INVOLCAN producing a 50 km-long array reaching outward from the island in the sea.By using a combination of traditional seismic preprocessing and array detection methods such as CovSeisNet1, we recover low frequency signals across the entire fiber. These steps enable us to detect and locate episodes of tremor linked to the volcanic activity which we compare with complementary observables.1 https://covseisnet.gricad-pages.univ-grenoble-alpes.fr/covseisnet/
Segregation of granular mixtures in an annular shear cell under shear, gravity, and convection
Authors: Chen Yanan , Ancey Christophe , Gray Nico
Published: March 2024

Particle-size segregation is a widespread process that affects granular materials. Under the influence of gravity and shear, particles segregate into distinct regions according to their size. To date, most experimental investigations have studied granular flows induced by gravity and shear. Less studied is the special case where the granular material is segregated under convection. We are concerned with this particular case. We conducted experiments by shearing bi-dispersed granular mixtures in an annular shear cell. Refractive-index matching (RIM) was achieved between particles and the surrounding fluid, which made it possible to visualize the granular flow when illuminated by a laser sheet. We reconstructed the particle spatial arrangement by applying the Hough Transformation to a continuous series of scans. Both axial and radial segregation was observed in experiments, i.e., small particles tended to percolate downwards and accumulated radially to the center region, while large particles were squeezed upwards and gathered in the exterior region. We found that axial segregation was related to gravity and shear, while the radial convection was related to the shear and convection. Solids volume fractions were computed as a function of time from three-dimensional scans of granular mixtures, from which segregation velocity was then derived. The experimental data provides interesting insights into segregation produced simultaneously in two directions.
Scientific Clowns - What are they? 
Authors: França George Sand , Barreto Pedro Stenio Caroca da Silva , Uieda Leonardo , Chaves Carlos Alberto Moreno , Myjnyk Julianize de Fátima , Lanza Tiziana
Published: March 2024

The art of clowning, an ancient practice, reveals remarkable potential to be explored in scientific outreach. In 2020, França et al. shared their experience integrating clowning into a show about scientific denial, which led to the creation of an innovative scientific workshop spanning two weeks. The aim is to reach high school teachers, undergraduate and graduate students, intending to disseminate geosciences unconventionally. In this context, we will present the experience in detail, highlighting the adopted approach, observed impacts, and the target audience we aim to reach. Additionally, we will explore strategies to expand this project and make it accessible to various locations. It is worth mentioning that during the pandemic, we ventured into our first foray into scientific outreach training through the scientific theater workshop. Despite being virtual, this hands-on approach proved surprisingly effective (link to the video: https://youtu.be/q0dkz8wtlxw?si=K63xn8XvzeVux3ri). Now, we will share the practical results obtained in the in-person and clown-focused format. We hope this initiative inspires new forms of scientific communication and contributes to the innovative and engaging promotion of geosciences.  França et al., 2020, Geoscience Communication - https://doi.org/10.5194/gc-4-297-202
Tracking Palaeotemperatures in Coniacian–Maastrichtian Seas
Authors: Price Gregory , Low Bryan
Published: March 2024

In this study the stable isotopes of belemnites, are presented from the Coniacian–Maastrichtian interval (~76–66 Ma) derived from the chalks of Yorkshire and Norfolk, UK deposited on the western North Atlantic shelf.  Cathodoluminescence of the belemnite revealed some diagenetic alteration occurring around the margins, central apical canal and prominent fractures, although large portions of the rostra were well preserved. Our oxygen isotope record reveals that during the Coniacian (at ~43 °N) the climate was relatively warm, with maximum mean temperatures of ~26 °C, followed by cooling to
Terracettes in the hyperarid Atacama Desert – fog-driven landforms of Holocene age?
Authors: May Simon Matthias , Hoffmeister Dirk , Brill Dominik , Opitz Stephan , Bubenzer Olaf
Published: March 2024

Terracettes are quasi-contour parallel step-like microtopographic features consisting of repetitious platform-type benches and slope-type risers and are documented from hillslopes in a range of climates. While a number of studies emphasize their formation by trampling of livestock and grazing animals (cat steps or stock trails), it has been shown that terracette formation may be explained by a number of natural processes, including solifluction or freeze-thaw processes, slumping, soil creep, or vegetation control. Despite this variability and the controversy about their origin, these micro-terraces may alter hillslope soil moisture and vegetation patterns, infiltration and surface hydrology, as well as downslope sediment flux, potentially disconnecting downslope conveyance processes of surface runoff. Given the process mechanisms discussed in these previous studies, the extremely hyperarid climate of the central Atacama Desert in northern Chile may be regarded as unfavourable for terracette formation; here, livestock and grazing animals are absent, moisture availability is extremely limited, and frost processes in elevations below ~1000 m asl are rare. Nevertheless, here we report on terracette-covered slopes in the central Atacama Desert located close to the Rio Loa canyon in the Coastal Cordillera that represents an important inland pathway for coastal fog. Based on sedimentological, geochemical (e.g., micro-X-ray fluorescence) and geomorphological investigations, thin section analyses, UAV-derived aerial photos, soil moisture monitoring as well as post-infrared infrared stimulated luminescence (post-IR IRSL) dating, we present geomorphological, chronostratigraphical and soil hydrological characteristics of the terracettes and discuss potential drivers of terracette formation. Our observations suggest a combination of wind and fog-related moisture supply, particularly during several day-long periods of sustained high relative humidity and fog occurrence, as the key driver for terracette formation, adding to the various processes discussed in previous studies. Post-IR IRSL dating of terracette platform sediments suggests a late Pleistocene to Holocene formation of the terracettes, thereby illustrating the role of fog in driving hillslope dynamics and shaping the desert landscape in the Atacama under past and present hyperaridity.
Solar Orbiter charging effects on electron measurements via SPIS simulation.
Authors: Herčík David , Stverak Stepan , Hellinger Petr , Gethyn Lewis , Nicolaou Georgios , Owen Christopher J.
Published: March 2024

The ESA mission Solar Orbiter is providing, besides other observations, in-situ measurements of the solar wind plasma. The boom mounted electron analyser (SWA-EAS) acquires ambient as well as spacecraft produced (photo-, secondary-) electrons. To correctly interpret and derive the solar wind electron population, we need to understand the artificial populations, their production rate, energy distribution, and directional dependence on the ambient conditions for the given spacecraft geometry. In order to investigate the various electron populations in the spacecraft vicinity, we incorporate a numerical model of the Solar Orbiter spacecraft into the Spacecraft Plasma Interaction Software (SPIS). Hereby, we present preliminary results and challenges of such simulations and their interpretations. 
Assimilating the Greenland ice sheet stratigraphy for reconstructing accumulation rates
Authors: Voigt Philipp Immanuel , Born Andreas
Published: March 2024

The thickness of englacial isochrones is the combined product of accumulation and dynamical thinning by the flow of ice.Dated ice stratigraphy data provides access to this archive , which in principle holds the potential for improving simulations and reconstructions  of the Greenland ice sheet. However, the combined effects of accumulation and dynamical thinning are convoluted and spatially heterogeneous, making it difficult to separate their respective contributions to the observed thickness of isochrones.Here we simulate isochrones explicitly using the Englacial Layer Simulation Architecture (ELSA) coupled with a fully transient thermomechanical ice sheet model. This enables us to link accumulation rates to the ice stratigraphy, including a physically consistent representation of dynamical thinning. By ensemble data assimilation techniques, the linear model response to changes in past local accumulation are estimated, enabling the inversion of the model and reconstruction of accumulation rates from stratigraphy. An iterative approach is chosen to account for the nonlinear response of ice flow to anomalous accumulation. The result is an optimized simulation of the Greenland ice sheet with an englacial stratigraphy matching the observations, forced by the reconstructed accumulation. Because the model is fully transient including ice dynamics, our approach also constrains ice sheet stability and sea level contribution.Here we present preliminary findings from inversions of idealized ice sheet stratigraphy, including some encouraging insights, physical and methodological limitations and challenges yet to be overcome.
Sensitivity of mid-Miocene simulations to different continental configurations
Authors: Renoult Martin , de Boer Agatha
Published: March 2024

The Langhian (15.98 - 13.82 Ma) was a stage of the mid-Miocene characterized by higher atmospheric CO2 concentrations than modern days and substantially warmer surface temperatures. The mid-Miocene has garnered growing attention as a potential analog for future climate change. Several climate models have assessed the influence of CO2 and geography on the Miocene warmth. In this study, we simulated the Langhian using a new unpublished paleogeography. This configuration notably features shallower and narrower access to the Arctic Ocean than has been previously documented. Despite CO2 concentrations equivalent to three times the pre-industrial levels (840 ppm) and the absence of ice sheets, we observe persistent sea ice in the Arctic Ocean and cooling of the Northern Atlantic Ocean. This cooling is related to the collapse of the Atlantic meridional ocean circulation. Conversely, a robust Pacific meridional ocean circulation emerges, which is less frequently observed in Miocene simulations. We investigate the reasons behind such behavior, by notably widening and deepening the Fram Strait; forcing a fixed, warmer vegetation; using a more recent atmospheric model with improvement to the physics. These adjustments underscore the critical role of geography in achieving an accurate simulation of the Miocene and facilitating more precise data-model comparisons.
Integration of Sentinel-1 and Sentinel-2 Datasets for River Discharge Estimation
Authors: Tural Ceren Yazıgülü , Yilmaz Koray K. , Tarpanelli Angellica
Published: March 2024

Rivers are corridors of freshwater that provide vital services for sustainable development and ecosystem functioning. Moreover, increase in frequency and severity of droughts and floods due to climatic change necessitates innovative and reliable techniques enabling continuous monitoring of river discharge to effectively manage risk. Since ground-based flow gauging stations are difficult to install and maintain, especially in remote regions, remote sensing methodologies have gained attention over the last decades.In this study, we integrate Sentinel-1 Synthetic Aperture Radar (SAR) data and Sentinel-2 optical data to make best use of their advantages, namely, observation capability on cloudy-days and higher spatio-temporal resolutions, respectively. In our methodology, we first identify the water surface area at selected river reaches where flow observations are also available. The conceptual framework for computing water surface areas within the specified study boundaries entails the utilization of water indices, specifically the Normalized Difference Water Index (NDWI) and Modified Normalized Water Index (MNDWI), for Sentinel-2 and histogram-based backscattering intensity thresholding for the Sentinel-1 platform. Later, we establish relationships between the computed surface water areas and corresponding flow measurements. The Google Earth Engine (GEE) platform serves as the operational foundation for executing the methodology. We validate the satellite-based discharge estimations using observed in-situ discharge data obtained from three selected USGS gauging stations along the Mississippi River, USA. According to our preliminary results, the coefficient of determination values between estimated and observed discharge datasets range between 0.49-0.79, 0.44-0.77 and 0.49-0.74 for the studied river reaches. The methodology is being tested for other river reaches along the globe to test and improve its river discharge estimation accuracy.
Linking tropical large-scale circulation and deep convection to subtropical marine low-clouds in the Pacific Ocean
Authors: McCulloch Danny , Lambert Hugo , Webb Mark , Vallis Geoffrey
Published: March 2024

Global Climate Models (GCMs) are essential for predicting the impact of climate change in the coming decades. However, the primary source of uncertainty in these predictions is our limited understanding of cloud feedback and its representation in models. Improving our knowledge of how changes in local heating rates affect low clouds via tropical overturning circulation is crucial to refining climate projections. In this study, we use an AMIP climate assessment configuration (with CMIP6 forcing) of the Met Office Unified Model to test the remote effects on subtropical clouds caused by localised changes in tropical atmospheric circulation.  We conduct this causal analysis by applying a heating/cooling perturbation in the free troposphere in a typical convecting and in a typical subsiding region in the equatorial Pacific Ocean. This method allows us to perturb large-scale circulation and track the subsequent effects on subtropical clouds. We find that when we apply a heating or cooling in the tropical free troposphere, the subsidence in the subtropics strengthens but we do not find a change in the low-cloud content. However, when we apply a cooling perturbation in the Southeast Pacific subsidence region, which increases subsidence, we get more local low-clouds. This is the opposite of what is suggested by previous studies which use a correlative approach on a global scale. We show how changing the intensity of the large-scale circulation in the equatorial Pacific influences subtropical low clouds, while tracking the effects of our perturbations in the transition regions between the tropics and subtropics. Our findings demonstrate a new way to conduct causal studies to better understand and isolate the influence of the free troposphere on large-scale circulation and subtropical clouds in a full GCM setup. Additionally, our findings emphasise how regional influences might differ from global results, highlighting the importance of recognising and quantifying regional contributions which dictate global trends. 
Primary producers during the early Earth 
Authors: Sanchez-Baracaldo Patricia
Published: March 2024

Primary producers convert light energy from the sun into chemical energy in the form of sugars, a fundamental process that has enabled life on Earth. Once ancestral cyanobacteria evolved, they played a crucial role in Earth's history by facilitating the rise of atmospheric oxygen, paving the way for the development of complex life forms. Despite its significance, the origins of photosynthesis are still not fully understood. During the talk, I will highlight key evolutionary events in the history of Cyanobacteria: 1) the Archean origin of PSII,  photochemical reaction centre that catalyses the light-driven oxidation of water to molecular oxygen; 2) the emergence of the crown group of Cyanobacteria; 3) the appearance of filamentous forms around the Great Oxidation Event at 2.32 Ga; and 4) the late emergence of marine planktonic groups between 800-600 Mya. Molecular evolution analyses reveal a significant time gap between the Archean origin of oxygenic photosynthesis and the appearance of planktonic forms at the end of the Precambrian era. By studying the 'genomic record,' we can now unravel how oxygenic phototrophs co-evolved with the Earth's biosphere, contributing to the habitability of our planet.
Automatic detection and characterization of Very Long-period seismic events for volcanic monitoring applications.
Authors: Gammaldi Sergio , Delle Donne Dario , Cantiello Pasquale , Bobbio Antonella , De Cesare Walter , Peluso Rosario , Orazi Massimo
Published: March 2024

Real-time seismological applications are now crucial for the monitoring and surveillance of active volcanoes, as they are useful tools for the early detection of volcanic unrest. In open-vent active volcanoes,  Very Long Period (VLP) seismicity, typically associated with mild and persistent explosive activity, is of crucial importance for volcano monitoring, as its variations in occurrence rate and magnitude may prelude a phase of unrest.  Here we show a new method for the automatic real-time detection and characterization of  VLP seismicity at Stromboli active volcano (Italy).The detection algorithm is based on the Three-Component Amplitude (TCA) obtained from waveform polarization and spectral analysis of the continuous recording, providing time of detection,  azimuth,  incidence,  amplitude, and frequency of the detected VLP events. The VLP amplitudes derived at all stations of the monitoring network, provided as peak-to-peak amplitudes and mean square amplitudes, are also used to perform an automatic localization of VLP source.VLP detections and characterizations derived from our automatic detection algorithm are compared with detection derived from manual and automatic inspections of the seismic record and with VLP time histories from available published VLP datasets.From this comparison, it turns out that the VLP detection time series produced by the automatic algorithm tracks fluctuations in the  VLP activity well,  as manually detected by the operators over a  ~20-year period, thus allowing us to include it into the real-time processing framework operating at Stromboli for volcano surveillance.
Innovative approach to investigate seafloor slow vertical deformation using bottom pressure measurements in a volcanic area: Campi Flegrei caldera (Italy) case of study
Authors: Morelli Rebecca Sveva , Riccio Rosario , Guardato Sergio , Caliro Stefano , Chierici Francesco , Macedonio Giovanni , Morra Vincenzo , Iannaccone Giovanni
Published: March 2024

Caldera systems generally show complex ground deformation phenomena, mainly associated with variations at different timescales of the hydrothermal systems normally hosted in calderas, magma storage and migration in the volcano plumbing system. Sometimes volcanic calderas are totally or partially submerged, which makes their study challenging, in particular if we consider shallow water systems. Many studies demonstrate the efficiency of adopting Bottom Pressure Recorder sensors (BPRs) for monitoring the vertical displacement of volcanic areas in deep-water environments. Moreover, BPRs measure the pressure at the seafloor over time, making possible their use to measure rapid or gradual inflation and deflation events. Here we propose an original approach to investigate the seafloor deformation over time in shallow volcanic areas using these instruments, and we applied it at Campi Flegrei caldera (Italy), a high-risk volcano system with a significant portion submerged in the Bay of Pozzuoli, near Naples. In this study we consider the data of two BPRs installed at the seabed within the Multiparametric Elastic-Beacon Devices and Underwater Sensors Acquisition (MEDUSA) infrastructure of the INGV Osservatorio Vesuviano, and we transform pressure measurements in equivalent water level changes to obtain the vertical seafloor displacement. To do this, we need the mean density of the water column during the periods of analysis, so we indirectly calculate it through the use of two tide gauges, one placed in the Gulf of Pozzuoli, and one located outside the deformation area for reference. The final results are then compared with the data acquired by the GPSs installed on the top of MEDUSA buoys, deployed at the same sites of the BPRs. The good correlation obtained supports the reliability of these sensors in measuring the seafloor deformation in a shallow water environment with an unprecedented level of accuracy.