bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of forest degradation as a subsidy for mitigating actions to preventing fires and wildfires in a new Amazonian frontier
Authors: Anderson Liana , Dutra Débora , Jones Chris , Mataveli Guilherme , Ferreira Igor , Leão Henrique , Cabral Beatriz , Fearnside Philip , Graça Paulo , Yanai Aurora , Silva Junior Celso , Medeiros Thaís , Dalagnol Ricardo , Braga Daniel , Peripato Vinícius , Burton Chantelle , Betts Richard , Aragão Luiz
Published: March 2024

Anthropogenic disturbances stand as the primary driver of degradation in the remaining Amazon forests, posing a significant threat to their future. Notable among these disturbances are edge effects, timber extraction, fire, extreme droughts and temperatures, which have been intensified by human-induced climate change. A pilot study aiming to integrate forest fire occurrence, timber extraction and climate change scenarios was developed for a new deforestation frontier in southwestern Amazonia. We integrated a series of remote sensing fire products, spatialized land tenure information, selective logging mapping techniques and Global Climate Models (GCMs) simulated projections of three SSPs (SSP climate forcing scenarios) for 2015–2100 period. The results showed that the increased deforestation trend occurred between 2003 and 2019 predominantly on public lands, following the implementation of the new forest code.  This surge contributed to a spike in fires, escalating from 66% to 84% in 2019. Over the period from 2007 and 2019, 2.4% of the primary forest was logged. By 2022, precipitation values aligned closely with SSP 5-8.5, and temperature values neared SSP 3-7.0. Projections for 2100 indicated an alarming increase of 5.19 ºC in overall temperature and a reduction of 55 mm in annual precipitation compared to 2003 baseline. The results indicate that the study region is already heading towards a less sustainable future. Logging activities, as well as agricultural production, are threatened by both increase in economic losses by fires and temperatures, and rainfall reduction. Implementing mitigation measures, such as fire-free land management, traceability controls for all wood production from logged forests, and addressing issues of land tenure and regulation are pivotal in steering the current development pathway towards a more sustainable pathway.
Grooves in the heart of glacial reconstructions: how to distinguish ice stream beds and iceberg keel ploughmarks in Earth's ancient glacial record
Authors: Jones Sharman , Busfield Marie , Le Heron Daniel , Holt Tom , Glasser Neil
Published: March 2024

We investigate the origin of an exceptionally well-preserved Late Palaeozoic soft-sediment glacial pavement at Oorlogskloof, South Africa and make a palaeoenvironmental reconstruction of deglaciation at this time. Elongate bedforms exposed at the base of the Dwyka Group have previously been interpreted as subglacial flutes and used as evidence of a fast-flowing soft-bedded ice stream. However, analysis of near-identical bedforms of a similar age in Brazil have revealed formation through iceberg ploughing in a shallow glaciomarine environment, warranting re-examination at Oorlogskloof. Fine-resolution orthomosaics and digital terrain models generated from aerial and ground-based structure-from-motion, coupled with field observations, were used to undertake detailed geomorphological mapping of landforms at the site. Elongate bedforms (oriented ESE-WNW) include V-shaped grooves and striations, tapered flutes, and sharp crested asymmetrical ridges with centimetre-scale sediment gravity flow lobes on their slopes. These are accompanied by arcuate push ridges with elongate limbs which parallel the adjacent bedforms. We propose the elongate features were streamlined by a grounded iceberg keel in a shallow marine environment, where the convex core of the arcuate push ridges indicates scouring towards the WNW. Asymmetrical ridges are interpreted as lateral berms since the preservation of sediment gravity flow lobes on their gently dipping slopes necessitates an unconfined substrate at the margins of the grounded iceberg keels. These features further testify to the soft sediment condition of the pavement at the time of bedform formation. Our analysis reveals a pavement formed by iceberg ploughing near a dynamic, retreating ice sheet margin and contests the evidence for an LPIA ice stream positioned over this site, with key implications for locating the position of the palaeo-ice margin over this region of Gondwana. We contend that the site also serves as a valuable sedimentary analogue for contemporary and Pleistocene deglacial landsystems that remain largely inaccessible on today's seafloor.
Carbon Emissions from Active Horticulture Peat Extraction Sites in Canada: Five Years of Field-based Measurements
Authors: Hunter Miranda L. , Clark Laura , Frei Rebecca J. , Strachan Ian B. , Roulet Nigel T. , Strack Maria
Published: March 2024

Peat extraction substantially alters the carbon dynamics, peat structure, and hydrology of peatland sites. In Canada, companies install drainage ditches every ~30 m, dividing the sites into fields of peat bounded by ditches, and remove the surface vegetation and upper acrotelm. Peat is then vacuum harvested, processed, and sold for horticulture use. Despite this disturbance covering only a small percentage of Canadian peatlands, the shift from being a net sink to a net source of carbon during the 15-35 years of extraction makes them an important system to study.We conducted research at eight actively extracted peatland study sites in Quebec (Eastern Canada) and Alberta (Western Canada), ranging from 3–28 years post the start of extraction. Our objectives were to i) assess spatial distribution of CO2 and CH4 emissions; 2) assess seasonal and interannual variability of these emissions; and 3) understand their environmental drivers. To do this, we employed measurement techniques at the plot and ecosystem scale. Plot scale chamber-based measurements of CO2 and CH4 were conducted weekly to biweekly from May to September at eight sites from 2018 to 2022, with each site being measured in at least one study year. The drainage ditches were hotspots of carbon emissions with around double and at least seven times the CO2 and CH4 emissions respectively, of the fields. Time since the start of extraction was a useful metric to estimate current CO2 emissions when sites were within one bog complex. More research will be required to extrapolate emissions to other locations however, as peat substrate quality differences between locations also contributed to variation in carbon loss.Ecosystem scale measurements of daytime March to October CO2 and CH4 emissions were conducted at a subset of the study sites for two to three years using the eddy covariance technique. We observed comparable March and April CO2 emissions to those in July, highlighting the importance of thaw dynamics on the yearly carbon budget. Interannually, CO2 emissions were lowest during a dry summer, suggesting a moisture limitation for decomposition at the surface under severe drainage. We found weak dependence of CO2 emissions on soil temperature, though it was strongest when the water table was within the top 40 cm of the peat.This research will aid in validating Canada’s emission factor values for peat extraction, which are currently based on a few measurements in Quebec at post extracted, unrestored peatlands. Using several different assumptions for wintertime emissions, we estimated annual CO2 budget of 256 – 385 g C m-2 yr-1, which agrees with Canada’s current Tier 2 emission factor value of 310 g C m-2 yr-1. Methane emissions accounted for < 1 g C m-2 yr-1. This research will also support process-based models looking at the effect of site management, and the changing climate, on carbon emissions from these sites.
A wind energy resource analysis in the Iberian Penindula under climate projections
Authors: Luna M. Yolanda , Díaz-Fernández Javier , García-Miguel Alonso , Calvo-Sancho Carlos , Castedo Ricardo , Ortega José J. , Bolgiani Pedro , Sastre Mariano , Martín María Luisa
Published: March 2024

The wind resource in the Iberian Peninsula has been analyzed using wind climate projections from the XX century to the end of the XXI century of the SSP5-8.5 scenario obtained from the MRI-ESM2.0 global climate numerical model. Six-hour wind speed and direction are seasonally grouped and from them, both the production of electrical power and the intensity of wind energy have been estimated throughout the temporal record. Two periods are considered in the dataset: the historical (1950 – 2014) and the future (2015-2100) periods. The non-parametric Mann-Kendall trend test is applied to identify significant wind energy intensity trends and the non-parametric Mann-Whitney test is applied over the entire domain's all-grid points to statistically evaluate the significant differences between wind energy intensity of different time periods. For an estimation of the evolution of the electrical power throughout the XXI century, the latest generation wind turbine SG 7.0-170 from Siemens-Gamesa has been used as a reference. Considering winter as the season of maximum wind energy production, the results show a future higher electricity production compared to the selected historical period in almost the entire Iberian Peninsula, although there is a decreasing production trend throughout the century. The remainder seasonal results indicate a general drop in electrical power due to a decrease of wind resource in the whole Peninsula throughout the century, especially in autumn with significant losses of more than 2 MW of electricity production in many Portuguese areas on the western coast of the peninsula.
Enabling the Forthcoming ROSE-L Sensor for Global Scale 3-D Earth Surface Deformation Retrieval Through a Two-Look ScanSAR Mode Configuration
Authors: Perna Stefano , Longo Francesco , Zoffoli Simona , Davidson Malcolm , Iannini Lorenzo , Lanari Riccardo
Published: March 2024

This work is focused on the possibility to enhance the observation capabilities of the forthcoming Synthetic Aperture Radar (SAR) ROSE-L (which stands for Radar Observation System for Europe at L-band) mission [1], [2], supported by the European Space Agency (ESA) as part of the Copernicus Expansion Programme.Specifically, we propose a solution aimed at enabling the currently designed ROSE-L system for a two-look ScanSAR modeconfiguration, without impairing key parameters, namely, the azimuth resolution and the range swath, of the original system, which is instead designed to basically achieve only a one-look ScanSAR mode configuration. In particular, following the analysis presented in [3], we propose to properly shape the radiated azimuth beam, doubling its width, without upsetting the original design of the ROSE-L radar antenna and taking advantage of the degrees of freedom offered by its current layout.The proposed ROSE-L two-look ScanSAR mode configuration presents several valuable advantages in different applications, among which we focus on the possibility to retrieve, at global scale and without azimuth gaps, the North-South deformation components of the displacement phenomena occurred on the ground through the so called Burst overlap interferometry technique [4].  [1] M. Zimmermanns and C. Roemer, “Copernicus HPCM: ROSE-L SAR Instrument and Performance Overview,” in EUSAR 2022; 14th European Conference on Synthetic Aperture Radar, Leipzig, Germany, 2022, pp. 1-6.[2] M. Davidson and R. Furnell, “ROSE-L: Copernicus L-Band SAR Mission,” in IGARSS 2021; IEEE International Geoscience and Remote Sensing Symposium, Brussels, Belgium, 2021, pp. 872-873.[3] S. Perna, F. Longo, S. Zoffoli, M. Davidson, L. Lannini and R. Lanari, “ A conceptual performance study on a two-look ScanSAR mode configuration for the forthcoming ROSE-L mission,” in IEEE Transactions on Geoscience and Remote Sensing, doi: 10.1109/TGRS.2023.3344537.[4] R. Grandin, E. Klein, M. Métois, C. Vigny, “Three-dimensional displacement field of the 2015 8.3 Illapel earthquake (Chile) from across- and along-track Sentinel-1 TOPS interferometry,” in Geophys.Res. Lett., vol. 43, pp. 2552-2561, 2016.
Understanding groundwater chemistry and residence times of two thermal springs in east-central Mexico.
Authors: Ramírez González Lorena , Escolero Oscar , Olea-Olea Selene , Medina-Ortega Priscila
Published: March 2024

Thermal springs are natural discharge points that can offer valuable information on groundwater circulation. The use of tracers to determine residence times can help us understand complex hydrogeochemical processes despite limited data availability.The present work aims to determine groundwater chemistry composition of two thermal springs located in east-central Mexico as well as understand some of the processes that may impact residence time estimation.Tritium and carbon-14 tracers indicated a significant component of pre-modern water. Major ions data collected showed both springs have concentrations of HCO3- greater than 1,000 mg/l and temperatures around 41 °C. Saturation indices showed water-rock interaction with geological formations present in the area, such as limestone sequence ‘El Doctor’, that could influence groundwater residence time. Isotope data (δ18O) was used to determine a recharge elevation ranging from 2900 to 3000 meters above sea level. Additionally, SiO2 geothermometers were also applied to quantify circulation depth and reservoir temperature.Analysis of hydrochemical composition, residence times, and any other information obtained from tracers, such as tritium and C-14, allows us to gain a better understanding of how groundwater systems work, along with a more accurate interpretation of results.
Seasonal forecasts of hydrological droughts over the Alps: advancing hybrid modelling applications
Authors: Ferrario Iacopo F. , Castelli Mariapina , Hussein Alasawedah M. , Liaqat Usman M. , Weerts Albrecht , Jacob Alexander
Published: March 2024

The Alpine region is often called the Water Tower of Europe, alluding to its water richness and its function of supplying water through several important European rivers flowing well beyond its geographical boundaries. Climate change projections show that the region will likely experience rising temperatures and changes in precipitation type, frequency, and intensity, with consequences on the spatiotemporal pattern of water availability. Seasonal forecasts could supply timely information for planning water allocation a few months in advance, reducing potential conflicts under conditions of scarce water resources. The overall goal of this study is to improve the seasonal forecasts of hydrological droughts over the entire Alpine region at a spatial resolution (~1 km) that matches the information need by local water agencies, e.g., resolving headwaters and small valleys. In this study we present the progress on the following key objectives:Improving the estimation of distributed model (Wflow_sbm) parameters by finding the optimal transfer function from geophysical attributes to model parameters and upscaling the information to model resolution.
Combining physical-hydrological knowledge with data-driven (ML/DL) techniques for improving accuracy and computational performance, without compromising on interpretation
Integrating EO-based hydrological fluxes, like streamflow, surface soil moisture, actual evapotranspiration, and snow waters equivalent, with the aim of regularizing the calibration/training, tackling the problem of model parameters equifinality.
Our work is part of the InterTwin project that aims at developing a multi-domain Digital Twin blueprint architecture and implementation platform. We build on the technological solutions developed in InterTwin (e.g. openEO, CWL and STAC) and fully embrace its inspiring principles of open science, reproducibility, and interoperability of data and methods.
Long-term evolution of continuous seismic signals at Piton de la Fournaise volcano inferred from the network covariance matrix.
Authors: Caballero-Leyva Emmanuel , Shapiro Nikolai , Journeau Cyril , Seydoux Léonard , Soubestre Jean , Barajas Andrés
Published: March 2024

Continuous seismic signals recorded in the vicinity of active volcanoes are composed of seismic waves generated by a variety of internal and environmental sources and propagating through different parts of the plumbing system. This implies that these signals are very sensitive to the state of the plumbing system. A change in the volcanic activity affects the properties of the seismo-volcanic sources while a change in the plumbing structure affects the media through which the seismic waves propagate. Network-based analysis of continuous seismic records has been developed to incorporate information from multiple stations simultaneously. Here we use an approach based on the network covariance matrix that combines an ensemble of inter-station cross-correlations. We compute the width of the eigenvalue distribution of this matrix at a given frequency in a moving time window, resulting in a compact time-frequency representation of continuously recorded seismic wavefield. We apply this analysis to ten years (2013-2023) of continuous seismic data from the Piton de la Fournaise volcano located in la Réunion, France. The resulting spectral width distributions indicate that continuous signals are characterized by multiple narrow spectral peaks, which are observed during co-eruptive tremors as well as during periods without visible volcanic activity. We propose a normalization process to enhance these peaks in both the frequency and time domains. We observe numerous spectral peaks in the 1-3 Hz frequency band that remain nearly constant for extended periods (weeks to months). We observe a distinct difference in the spectral peak distribution between co-eruptive and quiet periods, as well as significant variations during long-standing eruptions. Locations of sources of the co-eruptive signals correlate well with the eruption sites. The inter-eruptive signals seem to originate from a combination of environmental and weak internal sources, and changes in their spectral properties might reflect the medium changes after major eruptions.
Anti-urban systems, oracular archaeological complexes and hydraulic technologies adapted to the eastern montaña region of Ecuador: The Magic Valley of the Upano River
Authors: Yépez Alden
Published: March 2024

Located between the eastern Andes and the peri-amazonian basin of Ecuador, the Upano river covers a mountainous area of 6075.54 km² along its main course of 266.73 linear km. In its upstream, monumental archaeological complexes coincide with a visual domain of the very active volcano Sangay and are distributed mainly at the headwaters of the river basins that flow into the Upano, which have allowed the development of an adapted hydraulic technology during ca. 1400 BC to 1200 AD. This lecture will consider a palaeoenvironmental reconstruction with a Bayesian approach (ca. 4-0.5 kyr) to understand the aboriginal occupation and some of the main religious factors of the Upano River valley.
Impact of aquifer properties, well spacing and vertical offsetting of warm and cool plumes on ATES systems.
Authors: Jacquemyn Carl , Jackson Matthew D
Published: March 2024

Aquifer Thermal Energy Storage (ATES) can store and supply a high capacity of seasonal heating and cooling. Well-balanced and well-designed ATES systems provide a very efficient energy storage, up to around 70-90% and thereby play an important role in providing a sustainable, and low-carbon solution for heating and cooling. Factors affecting the efficiency and capacity of ATES deployments are mainly subsurface properties and related design decisions. We set up a framework to test the impact of a wide range subsurface and design parameters to deduce their impact on ATES system performance. Aquifer thickness, lateral permeability and permeability anisotropy are considered as main aquifer properties, and cool-warm well lateral spacing and vertical offsetting of cool and warm plumes as main design decisions. The thickness of the injection and production interval can be dictated by aquifer permeability variations and/or be chosen by varying screen length.  The parameters listed above are combined into dimensionless numbers, such as effective aspect ratio of the system and effective lateral spacing of wells to summarize and group different aquifers and possible ATES deployment designs. For a wide range of effective aspect ratios and effective well spacing ATES system behaviour is predicted by flow simulation and key performance indicators computed, including thermal efficiency, CO2 savings, cool/warm plume sizes and stored energy density. The first two indicate the potential expected capacity of ATES systems. The latter provide recommendations for best use of land area, especially if multiple ATES systems are planned in areas with high concentration of cooling and heating demand. Given heating and cooling demand, specific aquifer conditions and land area available for use, the predicted behaviour metrics will help design optimal ATES deployments and show the potential for energy savings across multiple different settings.Results indicate that ATES’ bidirectional subsurface thermal storage nearly always produces more energy than unidirectional open-loop systems, even when thermal recovery is low. Only when cold and warm plumes are placed side-by-side, closer than half thermal radius apart, negative thermal efficiency occurs, and more energy is put in the system than extracted. However, placing cold and warm plumes at very small spacing is still efficient, when plumes are also offset vertically, and similar thermal behaviour as large lateral well spacing is achieved.
Enhancing Flood Resilience: Geomorphological Insights into Lowland Riverscapes for Nature-Based Solutions
Authors: Güneralp Inci , Hasan Mahbub , Ahasan Rakibul , Hales Billy , Filippi Anthony
Published: March 2024

Aimed at achieving environmentally and economically smart growth in lowland riverscapes in the face of exacerbating flood threats, the elements of natural riverscapes, such as floodplain landforms, riparian forests, and wetlands can provide solutions to flood risk reduction. Geomorphological knowledge is crucial to working effectively with river processes and landforms in addressing flood hazards. In addition to unique landforms and habitats that can support flood mitigation, landscape-level geomorphological characteristics, such as geomorphological heterogeneity and connectivity, can also impact the attenuation and retention of downstream fluxes of water, sediment, and other materials, and thus resistance and resilience to floods. In this study, we employ a geomorphological approach to delineate the natural elements of lowland riverscapes as geomorphological habitats to assess their susceptibility to floods and erosion/sedimentation as well as their capacity to alleviate the negative impacts of floods. To delineate geomorphological habitats, we utilize a range of classification approaches and geospatial data including LiDAR-derived digital terrain models, airborne and satellite images, raster/vector data on vegetation, soils, and land-cover land-use. We then quantify the diversity, heterogeneity, and connectivity of delineated habitats using landscape ecological approaches and in the context of flood impacts and mitigation. Our geomorphological approach to riverscape characterization provides new insights on fundamental knowledge of natural elements as geomorphological habitats and their interconnections and interdependencies. This new knowledge has a high potential for developing geomorphologically derived nature-based solutions to flood management and enhancing flood resilience of lowland riverscapes.
Consolidation characteristics of offshore sediments in the Christiana, Santorini, and Kolumbo volcanic field, Greece (IODP Expedition 398)
Authors: Yoshimoto Takeru , Manga Michael , Beethe Sarah , McIntosh Iona , Woodhouse Adam , Chiyonobu Shun , Koukousioura Olga , Druitt Timothy , Kutterolf Steffen , Ronge Thomas ,   IODP Exp. 398 Scientists
Published: March 2024

An abnormal rapid accumulation of volcaniclastics is expected in sedimentary basins around submarine volcanoes. This phenomenon makes the sedimentary basin unstable because the drastic increase in overburden leads to generation of excess pore fluid pressure which prevent consolidation of sediments. Therefore, consolidation state of the sediments would be a crucial information for assessing the slope instability around volcanos.IODP Expedition 398 cored marine sediments in the Christiana, Santorini, and Kolumbo (CSK) volcanic field in the Aegean Sea of Greece. In this study, we performed consolidation tests on mudstones and calcareous oozes just below the thick volcaniclastics in three basins (Anafi, Anydros, and Christiana Basin) oriented roughly NE-SW including Santorini caldera. Consolidation trends (void ratio vs. applied stress) show clear yield stress which indicate maximum consolidation stress of sediments. Some of ooze-dominated mudstones show the effects of cementation in their consolidation trends.In the IODP site U1590 (Anydros Basin) and U1592 (Anafi Basin), consolidation yield stress of sediments was ~2 MPa lower than the overburden. It implies that the excess pore fluid pressure generates in the sediments and prevents the normal consolidation. The Anydros and Anafi basins represented underconsolidation state at 300-400 mbsf and ~300 mbsf, respectively. Both underconsolidated intervals are covered by >200 m thick volcaniclastics derived from the Santorini and the Kolumbo volcanos. Therefore, rapid sediment-supply (0.8-1.0 m/ky) from the submarine volcanos apparently makes the surrounding sedimentary basins unstable.On the other hand, IODP site U1591 (i.e., Christiana Basin) and U1599 (i.e., Anafi Basin) represents the normal-consolidation state and the consolidation yield stress balances the overburden. There is relatively thin cover of volcaniclastics (~100 m) above the non-volcanic sediments and the sedimentation rate is moderate (0.1-0.4 m/ky).In this presentation, we are going to compare the consolidation characteristics of three basins and discuss their spatial-temporal variation in relation to the sedimentation rate and physical properties of sediments.
Combining seismic tremor and GPS observations to characterize the seasonal evolution of the Greenland basal hydrologic system and its relationship to ice dynamics
Authors: Behn Mark , Fan Wenyuan , Lau Nicholas , Das Sarah , McGuire Jeffrey , Arnell Kirsten , Rines Joshua , Towns Erin
Published: March 2024

The mass-loss rate of the Greenland Ice Sheet is accelerating due to increased surface melt and changes in ice-sheet dynamics; however, our understanding of how and when increased melt may lead to increased ice velocity is limited in part by the difficulty in characterizing the evolution of the basal meltwater system and its effects on ice sheet-bedrock coupling.  To monitor the evolution of the basal hydrologic system and its relationship to surface ice velocities, we conducted a field experiment from May to September 2022 near North Lake on the western margin of Greenland. We deployed seismic and geodetic instruments that captured the seasonal evolution of the basal hydrologic system, as well as the drainage of two nearby supraglacial lakes.  Our seismic network included three small-aperture dense arrays, which recorded continuous data generated by the evolving hydrologic systems. The seismic arrays are used to detect and locate seismic tremor sources at the ice-sheet bed, likely correlated with basal meltwater flow.  We locate tremor sources every 5 seconds and use their spatiotemporal distributions to monitor the evolution of the basal flow system over the melt season.  Our observations show tremor activity increases starting around day 175, preceding the increase in ice surface velocities relative to the winter velocity.  Tremor activity peaks in the days before the two rapid lake drainage events (day 195), likely associated with precursory surface-to-bed drainage through a moulin west of North Lake.  Immediately after lake drainage, tremor activity shuts down, though ice velocities remain elevated over winter velocities.  Finally, around day 213 tremor activity increases, becoming more episodic, while ice velocities decrease toward winter velocities.  These observations provide new constraints on the interconnected feedback processes between supraglacial and subglacial hydrologic systems and suggest that ice surface velocities may not be directly correlated to the activity of basal meltwater flow over the melt season. 
Implementation of implicit filter for spatial spectra extraction
Authors: Nowak Kacper , Danilov Sergey
Published: March 2024

Scale analysis based on coarse-graining has been proposed recently as an alternative to Fourier analysis. It is now broadly used to analyze energy spectra and energy transfers in eddy-resolving ocean simulations. However, it requires interpolation to a regular mesh for data from unstructured-mesh models. We present an alternative coarse-graining method which relies on implicit filters using discrete Laplacians. This method can work on arbitrary (structured or unstructured) meshes and is applicable to the direct output of unstructured-mesh ocean circulation models. We also present a high-performance Python implementation of this method. In this implementation computation has been split into two phases: preparation and solving. The first one is specific only to the mesh. This allows for auxiliary arrays that are then computed to be reused, significantly reducing computation time. The second part consists of sparse matrix algebra and solving linear system. Our implementation is accelerated by GPU to achieve unmatched performance and scalability. This results in processing data based on meshes with more than 10M surface vertices in a matter of seconds. At present, the method is used to compute energy or power spectra of ocean flows.
Accurate seismic phase picking using High-Order Statistics: the case study of the Irpinia Seismic Array in Southern Italy
Authors: Messuti Giovanni , Palo Mauro , Scarpetta Silvia , Napolitano Ferdinando , Scotto di Uccio Francesco , Capuano Paolo , Amoroso Ortensia
Published: March 2024

Fault imaging and characterization of crustal structures, along with source parameter estimation, strongly depend on reliable direct seismic wave arrival times. To lower the detection threshold of small earthquakes and improve the quality of fault imaging, dense arrays of seismic stations are being installed more and more frequently in different parts of the world. Given the rising number of new, denser seismic networks and the growing demand for high-quality seismic catalogs, the use of automatic techniques is crucial to efficiently process and analyze the vast amount of seismic data, contributing to the advancement of seismic research and monitoring capabilities.The Irpinia fault system (Southern Italy) hosted in 1980 the M 6.9 earthquake and is currently monitored by the Irpinia seismic network (ISNet), which is composed of 31 seismic stations covering an area of about 100x70 km2 along the Campania-Lucania Apennine chain. ISNet was integrated by 200 seismic stations grouped in small-aperture arrays of 10 stations during the 1-year DETECT project (DEnse mulTi-paramEtriC observations and 4D high resoluTion imaging). DETECT focused on the acquisition of a unique multiparametric dataset and aimed to monitor and image the fault system during the inter-seismic phase fostering at the same time the collaboration among various institutions.The use of seismic arrays, in a region characterized by high seismic hazard, presents a unique opportunity to introduce a novel technique that accurately reveals the first arrivals of seismic phases of small earthquakes. We examined 226 micro-earthquakes, with magnitude ranging from -0.27 to 2.28, detected by the seismic arrays during the first six months of the DETECT project (September 2021 - February 2022). We present a novel approach that utilizes high-order statistics (HOS), computed on the vertical components of waveforms, to identify P-wave arrival times and provide reliability measurements for our predictions. The advantage of the arrays’ geometry enabled the integration of the HOS technique with a criterion designed to select the optimal onsets. The proposed methodology incorporated over 3,300 additional P-wave arrival times into the existing catalog. Furthermore, semblance measurements among traces recorded at the same array highlighted the superior quality of the selected picks compared to the existing ones.This work is partially supported by project TOGETHER - Sustainable geothermal energy for two Southern Italy regions: geophysical resource evaluation and public awareness financed by European Union – Next Generation EU (PRIN-PNRR 2022, CUP D53D23022850001).
The Stratified Inclined Duct: a new canonical laboratory experiment to study ocean turbulence and mixing
Authors: Lefauve Adrien , Couchman Miles , Linden Paul
Published: March 2024

We present a relatively recent laboratory experiment, the Stratified Inclined Duct (SID), that sustains a buoyancy-driven exchange flow and allows to accurately control and measure stratified sheared turbulence. The submesoscale turbulent mixing of momentum, heat, and salinity in the ocean have a leading-order but poorly constrained large-scale impact. We argue that SID may serve as a fruitful testbed for studying these processes, especially near boundaries, such as in estuaries.First, we introduce SID, which consists of two large (400 litres) reservoirs containing salt solutions connected by a long rectangular duct. The long-lasting  exchange within the duct has a Reynolds number of order Re ~ 1,000-10,000. The apparatus can be tilted at a small angle θ with respect to the horizontal, which energises the flow and increases turbulence levels, due to the emergence of 'hydraulic control'.Second, we present high-resolution experimental measurements of the three-dimensional velocity and density field within the duct which allow to delve into the energetics of stratified turbulence. SID uniquely allows the experimenter to control the level of turbulent kinetic energy dissipation, and to sweep through increasingly turbulent regimes by varying the key product Re*θ. The levels of turbulent intensity are comparable to those found in moderately turbulent patches in the ocean.Third, we demonstrate that a data-driven analysis combining automated image analysis, data reduction and unsupervised clustering discovered previously unsuspected patterns in a large SID turbulence dataset. Multiple types of energetic turbulence were found, as well as intermittent turbulence that cycles between these types through distinct transition pathways. We argue that this data-driven identification of turbulence is a stepping stone towards better physics-based parameterizations.
How H2O transport and trapping affect the dynamics of magmatic systems from melt generation to eruption triggering
Authors: Annen Catherine , Weinberg Roberto , Pinel Virginie , Burgisser Alain
Published: March 2024

H2O and other volatiles play a major role in the dynamics of magmatic systems from magma source to volcanic eruption. At the source, H2O facilitates melting and within the crust, H2O fluxing of hot rocks favours the formation and stabilisation of magma mush. H2O dissolved in melt lowers its viscosity and density and thus helps melt extraction and transport. H2O exsolution during magma transport causes crystallisation and stalling of the magma, while further exsolution in a crystallizing magma chamber increases pressure on the chamber walls and facilitates chamber failure and eruption. During the magma final journey towards the surface, formation and expansion of bubbles fragment the magma, increasing the explosivity of the volcanic eruption.We have developed numerical simulations that model flux melting in the deep crust, and other simulations that model H2O exsolution in a growing and crystallising magma chamber in the upper crust. A parameter that is crucial in both processes is the permeability of the magma, mush, and solid rocks through which H2O is moving.Our flux melting models show that due to complex interactions between the effect of H2O and heat, the amount of melt produced by flux melting depends on how fast H2O is transferred relative to heat. By absorbing latent heat, H2O flux melting decreases temperatures and promotes heat transfer in the melting areas. The extent of the melting region depends on the competition between the transfer of H2O, which induces melting and cooling, and the transfer of heat that smooths temperature anomalies. The amount of crustal melting also depends on permeabilities contrast. The presence of an impermeable layer above a more permeable layer increases the production of melt by trapping H2O in the permeable layer.The ease of transfer of exsolved H2O within a crystallising magma body depends on crystal fractions. Our models of magma chambers growth and solidification show that preferential transfer of H2O through the mush that surrounds a magma chamber results in the formation of H2O layers at the top the mush and in the chamber’s roof. If the permeability of the country rocks is low, the H2O layers grow, their buoyancy increases, and the pressure eventually exceeds the yield strength of the country rock and causes fracturing. Depending on how well the H2O layers connect to the liquid magma in the chamber below, fracturing of the country rock can result either in the release of H2O only and possibly causes a bradyseismic crisis, or in the release of H2O, mush, and magma, and triggers a crystal-rich eruption.We know from volcano degassing and from petrological data that magmas are rich in H2O. However, our knowledge of how this H2O is transferred from magmas and through the crust is limited. This knowledge is important though as our simple numerical models indicate that the modalities of H2O transport and accumulation strongly affect the dynamics of a magmatic system.
Shallow Subsurface Velocity Structure using the ambient noise for the Himalaya Region.
Authors: Kumar Yogesh
Published: March 2024

The Gorkha earthquake 25 April 2015 has attention the entire worlds to Himalaya due to large scale damage caused in the region. This heavy damage happened due to site amplification of the ground motion was clearly evident during the Nepal earthquake. The Himalaya situated in the central seismic gap (CSG) region suggested by Khattri (1987). Region itself has large possibilities of site amplification which can result high damage during future earthquakes. Average shear wave velocity up to 30 m depth are being described as Vs30. Correct estimates of Vs30 provides useful tool for site classification and site amplification at any location. This is important parameters for the engineering uses and is also used in seismic microzonation study of any area. In the present study Vs30 is measured in various locales of the Himalaya using the technique of multi-channel analysis of surface wave (MASW). Data has been acquired from the Sub-Himalaya to Lesser Himalaya for calculation of Vs30. Dispersion curves are obtained using the MASW data and are compared with the theoretical dispersion curve to obtain the shear wave velocity model at various point. Detail analysis of results obtained at various locations suggests that Vs30 in this region varies from 150 ms-1 to 900 ms-1.
From Point Clouds to Forest Complexity: Addressing Challenges of Structural Analysis of Forest Landscapes using Wall-To-Wall Airborne Laser Scanning Data
Authors: Iglseder Anna , Schimpl Lorenz , Hollaus Markus
Published: March 2024

Forests play a cruical role in global ecosystems, providing habitats for many species, having the potential for high biodiversity and offering substantial carbon storage. Characterizing and monitoring the structural properties of these ecosystems are essential for modeling various ecosystem services and designing management and conservation strategies.Airborne Laser Scanning (ALS) allows us to acquire comprehensive 3D data due to its ability to penetrate the canopy and provide surface data as well as below-canopy information about vegetation structure. The emerging widespread accessibility of openly available wall-to-wall ALS datasets, in some cases even multi-temporal, increases the possibilities to thoroughly analyze forest structures. However, for large-scale applications, challenges arise from variations of data resolution and quality as a result of differences in sensors, point densities or acquisition dates or the sheer volume of data to process.In this study, we present a unified, point-density-independent voxel-based approach to address these challenges of high-resolution wall-to-wall ALS data analysis in forest environments. Besides canopy height, we derive structural parameters like height quantiles, fractional cover, vertical complexity, understory height and number of vegetation layers to characterize the structural complexity of the forest landscape on different scales up to a level of detail of 1 m. These data are further combined and utilized for segmentation of structurally homogeneous forest areas.The study site is the Vienna Woods Biosphere Reserve, located in the federal states of Lower Austria and Vienna (Austria), covering approximately 1056 km² of diverse forest landscape. This region encompasses diverse forest types (a.o. beech, oak-hornbeam, black pine), various topographical and geological conditions as well as different management types and levels of protection. To get full point cloud coverage of the area, it is necessary to combine point clouds from up to ten different scanning campaigns.Initial test runs show promising results and demonstrate the possibilities of this approach to derive sound, area-wide structure metric and further characterize the forest based on structural varieties, provide easy-to-read maps for further deployment in operational use of stakeholders and show potential for structure-based segmentation of forested areas. These structure-based segments can serve as a base for habitat mapping, monitoring or management.
An optimization and simulation framework for water-energy-environmental nexus under uncertainties: A case study in the city cluster along the middle reach of the Yangtze River, China
Authors: Liu Haoyuan , Zhang Xiang
Published: March 2024

Water, energy and the environment are inextricably linked. Complex and volatile global situations pose serious challenges to long-term stable and sustainable social development, resulting in many uncertainties in maintaining regular water and energy supplies and avoiding environmental degradation. Based on the nexus theory, it has become an urgent global and regional need for policy makers and scientists to consider water, energy, and the environment nexus (WEEN) as a complex system in order to deal with the water and energy issues brought about by rapid urbanization, the synergistic response of the environment under climate change, and the corresponding potential risks. Aiming at these problems, a simulation and optimization framework for WEEN complex systems is proposed by combining the system dynamics model, Gaussian white noise, and NSGA-II method. A system dynamics model integrated with Gaussian white noise is used to characterize the feedback relationships among the elements within the different subsystems of water resources, energy, and environment under uncertainty. Taking the city cluster in the middle reaches of the Yangtze River (CCMRYR) in China as the research object, the evolution of the WEEN complex system is simulated under different uncertainty conditions such as climate change conditions and policy backgrounds. In addition, an optimization method based on NSGA-II algorithm is constructed for solving the optimal development strategy of WEEN complex system. The results show that: Following the current development path, by increasing the proportion of energy conservation and environmental protection expenditures by 0.033%, as well as adjusting the ratio of the primary, secondary, and tertiary industries from 5.8:29.0:59.1 to 6.9:28.3:59.7, it is possible for CCMRYR to achieve a reduction of 1.31 billion tons of total water consumption, a reduction of 12.17 million tce of total energy consumption, and a decrease of 0.13×106 of total pollution equivalent in 2035.
A distributed rainfall-runoff model for the investigation of climate change effects on river floods in the European Alps
Authors: Lombardo Luca , Parajka Juraj , Valent Peter , Viglione Alberto
Published: March 2024

The worsening of global climate change has increased both the frequency and intensity of extreme weather events, significantly impacting the dynamics of flooding. This convergence of factors results in intensified and prolonged precipitation, leading to river overflow and catastrophic floods. Elevated temperatures and rapid snowpack melting further contribute to the increase of flood risk. These impacts are particularly pronounced in mountainous regions, where the combination of steep terrain and increased precipitation amplifies the risk of flash and snowmelt generated floods.The CLIM2FLEX project aligns with this intricate and evolving context, aiming to assess, under potential climate scenarios, the variations in the frequency and intensity of river floods generated by various mechanisms. Within the project framework, a crucial aspect involves constructing a modeling chain, complete with a hydrological module. This component is dedicated to translating climate inputs into continuous discharge time series, enhancing the project's capacity for in-depth analysis and dynamic modeling.To do so, the main idea is to use a "new version" of the "TUWmodel" conceptual hydrological model to account for the inter-basin transfer of water and flood waves propagation (from upstream catchments to downstream catchments) through the implementation of a new routing routine based on the introduction of a Nash-Cascade module. Different calibration strategies are used at gauged sites to estimate the best model parameters. A machine learning based regionalization approach (HydroPASS) is then applied to infer model parameters at ungauged sites for hydrological streamflow predictions. The focus of this study encompasses the entire Great Alpine Region (GAR), posing significant modeling challenges. The region is predominantly characterized by mountainous terrain, consisting mainly of small catchments. Here, the effects of snow accumulation-melting cycles, as well as the presence of glaciers and other small-scale features, play a particularly crucial role.The presentation at EGU will delve into preliminary findings concerning the applicability and reliability of the proposed hydrological modeling chain structure, along with the anticipated future steps in the research.