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Unravelling the physicochemical drivers of heavy metal adsorption on carbonaceous nanomaterials: Implications for the environmental fate of contaminants in mixtures
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Precise relocation of the 14 August 2021 M<sub>w</sub> 7.2 Nippes, Haiti, earthquake sequence using broadband and citizen-hosted short-period seismometers
No full textInternational audienceOn 14 August 2021, the Southern Peninsula of Haiti experienced a Mw 7.2 earthquake, 15 years after the devastating Mw 7.0 event that struck the capital city of Port-au-Prince on 12 January 2010. We use the data from a local temporary broadband seismic network, a national network of low-cost seismometers, and regional seismic networks, together with a probabilistic, global-search, non-linear location method (NLL-SSSTcoherence), to obtain a catalog of 5341 precisely relocated events spanning 20 August 2021 to 6 February 2022, with local magnitudes ranging from 0.5 to 5.6. We compute focal mechanisms for a subset of 73 events through waveform inversion. The catalog can be split into aftershocks directly related to the Nippes earthquake rupture process, and two off-rupture clusters. A first one concerns the Anse-à-Veau-Miragoâne area and corresponds mostly to the aftershock sequence of two Mw 5.3 and 4.9 earthquakes that likely activated a segment of the offshore, south-dipping, Jérémie-Malpasse reverse fault system. A second sequence, offshore Jérémie and clustered close to the offshore trace of that same fault, started immediately after the Nippes mainshock and continued during the entire time interval of the present study. The swarm-like temporal distribution of this sequence, as well as evidence for directional propagation of the epicenters, indicate that it was likely driven by fluid migration. We interpret this seismicity as the result of oblique sub-crustal slip on a south-dipping fault which accounts for oblique convergence between the Gonâve and Caribbean plates in southern Hispaniola. Strain in the crust then partitions between reverse faulting on the Jérémie-Malpasse fault system, strike-slip on the Enriquillo fault, and hybrid faulting in between. Seismic hazard assessment for the region should therefore account for faults other than the Enriquillo fault as potential sources for future earthquakes
Assessing simplified approaches in modeling rainfall-induced landslides using Richards' equation with Biot poroelasticity
No full textInternational audienceCoupled Hydro-Mechanical (HM) models, which involve the interaction between fluid flow and mechanical processes in porous media, are essential for simulating rainfall-induced landslides (RILS). A common strategy to investigate RILS is through the Biot poroelasticity approach combined with the Local Factor of Safety concept. While the two-phase flow and mechanical equations are well-documented for modeling HM processes in variably saturated conditions, the use of Richards' Eq. (RE) in this context remains underexplored. This paper aims to address this gap by providing a comprehensive formulation for coupling RE with mechanical equations and evaluating the impact of various model simplifications on the reliability of RILS predictions. We present the theoretical development of the original mathematical model that leads to a strong coupling between flow and mechanical equations. We also review the different simplification approaches proposed in the literature to reduce the complexity of the original model. A straightforward implementation of these approaches in COMSOL is provided, with validation against established benchmarks. Through a comparative analysis of different approaches, using both hypothetical benchmark and real case study in Azerbaijan, this study provides new insights into the balance between model complexity and prediction accuracy. While simplified approaches are commonly used in literature, this study advocates for the fully coupled model, which delivers the most reliable results. The employment of advanced numerical techniques enhances the computational performance of the fully coupled model, making it competitive with simplified approaches
Canadian net forest CO2 uptake enhanced by heat drought via reduced respiration
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The North Balearic Front as an ecological boundary: zooplankton fine-scale distribution patterns in late spring
No full textInternational audienceObservations, models and theory have suggested that ocean fronts are ecological hotspots, generally associated with higher diversity and biomass across many trophic levels. Nutrient injections are often associated with higher chlorophyll concentrations at fronts, but the response of the zooplankton community is still insufficiently understood. The present study investigates mesozooplankton stocks and composition during late spring, northeast of Menorca, along two north-south transects that crossed the North Balearic Front separating central waters of the Northwestern Mediterranean Sea gyre from peripheral waters originating from the Algerian basin. During the BioSWOT-Med campaign, vertical triple-net tows with 200 and 500 µm meshes were carried out at three depths (100, 200, and 400 m), and the samples were processed with ZooScan to classify organisms into eight taxonomic groups. Zooplankton distributions were analyzed for the surface layer (0–100 m), a mid-depth layer (100–200 m), and a deeper layer (200–400 m). The results did not show a significant increase in biomass in the front in any layers. The NBF appears to act as a boundary between communities rather than a pronounced area of active or passive zooplankton accumulation. Analyses of stratified vertical distributions of zooplankton highlighted distinct taxonomic compositions in the three layers, and a progressive homogenization of community structure with depth, reflecting a weaker impact of hydrological processes on deeper communities. The clearest impact of the front was within the upper 100 m, where the mesozooplanktonic taxonomic composition differed between the front and adjacent water masses, with a decrease in all taxonomic groups except Cnidaria, which increased dramatically. In the two deeper layers, the front also influenced community composition, although to a lesser extent, with marked increases in Foraminifera and Cnidaria. Moreover, the northern water mass and the front were dominated by large copepods, while the southern water mass exhibited higher zooplankton diversity and smaller-sized copepods. The results of this study highlight the complexity of processes shaping planktonic communities over time and space in the NBF zone and its adjacent waters. These processes include zooplankton stock reduction in the transitional post-bloom period, marked effect of diel variation linked to vertical migrations, and potentially the impact of storm-related mixing in the surface layer that can disrupt established ecological patterns
Planetary, Solar and Heliospheric Radio Emissions X
No full textInternational audienceThe 10th edition of the international workshop on "Planetary, Solar and Heliospheric Radio Emissions” was held in June 2025 in Marseille, France, in continuation of a series of previous workshops successively held in Graz (Austria) in 1984, 1987, 1991, 1996, 2001, 2005, 2010 and 2016 and in Ireland (Dublin) in 2022. The proceedings of this workshop have been double peer-reviewed under the responsability of a scientific editorial committee composed of L. Lamy, C. K. Louis, G. Fischer, D. Morosan and P. Zarka and are published as a digital book entitled “Planetary, Solar and Heliospheric Radio Emissions X”
Geodynamo Simulation Explorer: a filterable and visualisable catalogue to explore geodynamo simulations
No full textWe present a new web tool, Geodynamo Simulation Explorer, to survey available published simulations of rapidly rotating spherical dynamos.With numerical codes and computers being increasingly efficient, recent years have seen a surge in the number of publications presenting such computations.Our tool comes as an interactive catalogue that allows exploring existing dynamos with respect to input and output dimensionless parameters, choosing from various dynamo setups (e.g. choice of boundary conditions, couplings at play, etc.), with the possibility to test scaling laws on a filtered set of simulations. It also links each dynamo to its associated publication and possibly to online datasets.Thought of as a collaborative and scalable initiative, the web interface allows uploading new simulation metadata.The whole interface, displayed as a website, is designed for the community to have a better overview while driving transparency, open-source initiatives, and FAIR principles (Findable, Accessible, Interoperable, Reusable).Check it out and feed it at https://geodyn.univ-grenoble-alpes.fr/explorer/
GLIMPSE-D: An Exotic Balmer-Jump Object at z=6.20? Revisiting Photometric Selection and the Cosmic Abundance of Pop III Galaxies
No full textInternational audienceWe present deep JWST/NIRSpec G395M spectroscopy of GLIMPSE-16043, a promising Pop III candidate originally identified through NIRCam photometry as having weak [OIII] emission. Our follow-up reveals clear [OIII] emission, ruling out a genuine zero-metallicity nature. However, the combination of the measured line fluxes and photometry indicates that its spectral energy distribution requires an extraordinarily strong Balmer jump ( mag) and H equivalent width ( Å), features that cannot be reproduced by current stellar+nebular or pure nebular photoionization models. The only models approaching the observations to almost within involve a hot ( K) single blackbody embedded in a low- nebular environment, suggestive of scenarios such as a tidal-disruption event or a microquasar with strong disk winds. This cautions that photometric Pop~III selections are vulnerable to contamination when the rest-frame optical continuum is undetected. Motivated by this, we refine the photometric Pop III selection criteria to exclude the locus of extreme Balmer-jump objects. The revised criteria also recover the recently reported spectroscopic candidate AMORE6, demonstrating that the updated selection preserves sensitivity to genuine Pop III-like sources while removing key contaminants. Applying the refined criteria across legacy survey fields and five newly released CANUCS lensing cluster fields, we revisit the Pop III UV luminosity function and estimate the Pop III cosmic star-formation rate density to be --~~yr~cMpc at --7, falling in the range of current theoretical predictions
Metabarcoding and metagenomic data across aquatic environmental gradients along the coasts of France and Chile
No full textInternational audienceAbstract Coastal marine environments, such as lagoons, fjords or estuaries, experience pronounced environmental variability, with fluctuations in salinity, temperature and nutrient levels shaping microbial community structure and function. These gradients result in diverse habitats, which may harbour taxonomic and genetic novelty with biogeochemical and biotechnological relevance. To explore microbial diversity and functional potential across these dynamic ecosystems, we sampled 26 sites along the coasts of France and Chile, including lagoons, estuaries, fjords, harbours, as well as coastal and offshore marine sites. Surface waters were collected from all sites, with deeper layers included at three sites. Monthly sampling at six sites in France enabled the assessment of seasonal dynamics. In total, 116 samples were processed for both metabarcoding and metagenomic sequencing yielding over 53,000 amplicon sequence variants (ASVs) and 1,372 metagenome-assembled genomes (MAGs). This dataset further includes a comprehensive gene catalogue and environmental variables such as salinity, temperature, nutrient concentrations, productivity, as well as oxygen consumption metrics collected across the different ecosystems
Terahertz Imaging of Early Stage Thermal Transformations in Oil Shale
No full textInternational audienceThe characterization of oil shales is essential for evaluating their quality and industrial potential. Existing techniques, such as X-ray tomography (XCT), scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS), infrared (IR) and Raman spectroscopies, and nuclear magnetic resonance (NMR), provide valuable information. However, none of these methods offer millimetric/sub-millimetric-scale resolution with direct sensitivity to simultaneous changes in both water and organic matter within a bulk sample. To address this limitation, terahertz (THz) imaging has previously been applied to oil shales; however, no studies have explored its use under varying temperature conditions of the sample. This is particularly relevant, as heating the samples at low temperatures (<200 °C) can provide new insights into their structural and compositional evolution. Thus, in this work, we acquired THz images after sequential heating an oil shale sample at 40, 150, and 200 °C for 15 h each, in order to monitor its change during thermal evolution. The results revealed, for the first time, changes in the THz images arising from the evaporation of free water, the release of bound water from clays, and transformation of organic matter. These findings were validated and explained by complementary analyses, including X-ray diffraction (XRD), XCT, and Rock-Eval pyrolysis. Furthermore, a first effective absorption and refractive index model was proposed, which enabled the estimation of free and bound water evaporation