Semi-empirical forecast modelling of rip-current and shore-break wave hazards
Sandy beaches are highly attractive but also potentially dangerous environments for those entering the water as they can be exposed to physical hazards in the surf zone. The most severe and widespread natural bathing hazards on beaches are rip currents and shore-break waves, which form under different wave, tide, and morphological conditions. This paper introduces two new, simple semiempirical rip-current and shore-break wave hazard forecast models. These physics-informed models, which depend on a limited number of free parameters, can be used to compute the time evolution of the rip-current flow speed V and shore-break wave energy E sb . These models are applied to a high-energy mesotidal-macrotidal beach, La Lette Blanche, in southwest France, where intense rip-currents and shore-break wave hazards co-exist. Hourly lifeguardperceived hazards collected during patrolling hours (from 11:00 a.m. to 07:00 p.m. LT (UTC+2)) during July and August of 2022 are used to calibrate the two models. These data are also used to transform V and E sb into a five-level scale from 0 (no hazard) to 4 (hazard maximised). The model accurately predicts rip-current and shore-break wave hazard levels, including their modulation by tide elevation and incident wave conditions, opening new perspectives for forecasting multiple surf-zone hazards on sandy beaches. In addition, daily-mean hazard forecasts demonstrate even greater predictive skill, which is important for conveying straightforward messages to the general public and lifeguard managers. The approach presented here only requires a limited number of beach morphology metrics and allows for the prediction of surf-zone hazards on beaches where wave and tide forecasts are available.
(Natural Hazards and Earth System Sciences. vol. 25, n° 1561-8633, pp. 2379–2397, 08/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR ETTIS, INRAE, SMGBL, UR EABX, INRAE
Tidal Pumping, Alkalinity Production and Export: An Overlooked Carbon Sequestration Process in Salt Marshes
(08/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Rapport intermédiaire du projet Vigie-Lacs
L’objectif du projet est d’acquérir des connaissances scientifiques indispensables à la préservation des communautés de plantes aquatiques des lacs et étangs du littoral aquitain fortement menacées par les activités humaines et le changement climatique. Ce projet pluridisciplinaire fait appel à plusieurs domaines scientifiques complémentaires, telles que l’écologie des communautés, l’autécologie, la biogéochimie, les biostatistiques, la génétique ou encore l’hydrogéologie.
(pp. 24, 08/04/2026)
UR EABX, INRAE, ECLA, USMB [Université de Savoie] [Université de Chambéry], INRAE, OFB, BioGeCo, UB, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
History of the sedimentary regimes of the Aquitaine margin (Bay of Biscay, France) at the outlet of its main tributaries during the last millennium: a mirror of the North Atlantic and European climates
The present work is based on the analysis of two hemipelagic sequences collected off the two main fluvial tributaries that enter the southern Bay of Biscay along the Aquitaine margin: the Gironde estuary, for core JB7-ST3c retrieved from the West-Gironde mud patch; and the Adour river, for core MD03–2693 retrieved from the Capbreton canyon meanders. Their positioning, at the northern and southern edges of the Aquitaine shelf, not only allows us to obtain a synoptic view of the southern Bay of Biscay past oceanography, but, over the last thousand years covered by these archives, also provides access to key contextual elements related to local as well as global hydroclimatic forcings. This article focuses on the interpretation of the sedimentological signal based on key X-ray fluorescence (XRF) elemental profiles obtained along the cores, within the framework of coherent age models newly built for the two sequences. The consistency of the two records allows us to robustly relate the evolution of the XRF profiles to the hydroclimatic regime of the Bay of Biscay, and to compile and discuss a chronicle of the environmental events that have marked the sites. This is achieved through a regional scale analysis, encompassing synchronous occurrences on the proximate continent, complemented by a broader synoptic perspective within the context of the well-documented European and North Atlantic historical frames. This chronicle is pivotal in comprehending the correlation between continental and oceanic regimes along the Euro-Atlantic margin, in addition to their links to the climatic processes that govern the Northern Hemisphere region. Our results clearly discriminate specific climatic trends, highlighting the Medieval Warm Period, the Little Ice Age and the Current Warm Period as contrasted intervals. The climatic patterns identified during these specific phases are discussed in the light of recent advances in our knowledge of their modes of variability, and raise the question of teleconnections between the North Atlantic Oscillation, Atlantic sea-surface conditions and dynamics, together with atmospheric ones and especially storminess over Europe.
(Global and Planetary Change. vol. 255, n° 0921-8181, pp. 105039, 08/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Contamination des sols français par les résidus de pesticides
La contamination de l’environnement par les résidus de pesticides est une préoccupation croissante par les acteurs publics au vu de leur omniprésence dans tous les milieux et leurs impacts directs et indirects sur la biodiversité et la santé humaine. Cependant, les études traitant de la contamination des sols par les résidus de pesticides sont très peu nombreuses, témoignant du manque de connaissance sur l’état de la contamination des sols et les impacts potentiels sur la biodiversité. Le projet Phytosol, financé entre 2018 et 2022 par l’Anses et coordonné par INRAE a permis d’acquérir des données inédites de 111 substances sur 47 sols prélevés dans le cadre du Réseau de mesures de la qualité des sols (RMQS). Les résultats de cette étude, détaillés dans le rapport suivant et publiés en 2023 dans la revue Environmental Science Technology, démontrent ainsi que 98% des sols prélevés contiennent au moins un résidu de pesticides, y compris des sites sans traitements phytosanitaires tels que les prairies permanentes, les sols forestiers ou encore des sols de parcelles en agriculture biologique. L’évaluation des risques indique également un risque modéré à fort pour les vers de terre notamment dans les sols de grandes cultures. Enfin, la confrontation avec les applications de produits phytosanitaires a mis en évidence la présence de certaines substances bien au-delà de leur temps de dégradation théorique et à des concentrations supérieures à celles attendues. Le déroulement de l’étude (mise en place, méthodologie) ainsi que les résultats détaillés sont présentés dans ce rapport.
(08/04/2026)
Info&Sols, INRAE, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Hourly valve opening data of oysters Ostrea edulis measured during a one-year semi-controlled experiment
This dataset shows the hourly valve behavioral data of the 32 oysters Ostrea edulis throughout the year of the experiment as well as the temperature recorded by each HFNI valvometer. The oyster valve behavior is characterized by 3 parameters: the Valve Opening Amplitude (VOA, the percentage of the valve opening relative to maximum opening), the Valve Opening Duration (VOD, the percentage of time that an oyster spends with its valves open), and the VOA/VOD. For each parameter, the data are presented for each oyster and as a group average for each condition. Missing data correspond to the death of oysters or the stopping of recording by a HFNI valvometer.
(08/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Hourly valve opening data of oysters Crassostrea gigas measured during a one-year semi-controlled experiment
This dataset shows the hourly valve behavioral data of the 32 oysters Crassostrea gigas throughout the year of the experiment as well as the temperature recorded by each HFNI valvometer. The oyster valve behavior is characterized by 3 parameters: the Valve Opening Amplitude (VOA, the percentage of the valve opening relative to maximum opening), the Valve Opening Duration (VOD, the percentage of time that an oyster spends with its valves open), and the VOA/VOD. For each parameter, the data are presented for each oyster and as a group average for each condition. Missing data correspond to the death of oysters or the stopping of recording by a HFNI valvometer.
(08/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Modification des régimes de sédimentation en rade de Brest en réponse aux pressions climatiques et humaines
(08/04/2026)
LUSAC, UNICAEN, NU, INTECHMER, Cnam, GEO-OCEAN, UBS, IFREMER, INSU - CNRS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SHOM, LEMAR, IRD, IFREMER, UBO EPE, CNRS
Simple physics-based rip current and shore-break wave hazard predictors for beaches in southwest
Sandy beaches are attractive yet potentially dangerous environments due to physical hazards in the surf zone. The most severe natural hazards are rip currents and shore-break waves, which form under varying wave, tide, and morphological conditions. This study introduces two simple, physics-based models to forecast channel rip current flow speed V and shore-break wave energy Esb. These models were applied to La Lette Blanche, a high-energy meso-macro-tidal beach in southwest France, where both hazards coexist. Lifeguard-perceived hazard data collected hourly from July to August 2022 during patrol hours (11 AM–7 PM) were used to calibrate the models. This data also informed a 5-level hazard scale, from 0 (no hazard) to 4 (maximum hazard). The models accurately predict hazard levels, accounting for tidal and wave influences. Requiring only basic beach morphology metrics, this approach offers a promising tool for forecasting surf-zone hazards on beaches with minimal morphological data and available wave forecasts.
(08/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UR ETTIS, INRAE, UR EABX, INRAE
Quantitative measurement of benthic foraminifera sediment reworking using a three-dimensional sensor
Despite their worldwide distribution and very high densities, the contribution of benthic meiofaunal species to sediment reworking has largely been neglected in bioturbation research. This is partly due to the challenge in obtaining reliable measurements of these minute size organisms. So far, only a handful of studies have investigated the influence of these microbioturbators on particle transport processes at the sediment surface. These studies most often used the surface image analysis (SIA) method, which indirectly estimates surface sediment reworking rate (SSRR) by tracking the position of individuals at the sediment surface over time. Here, focusing on benthic foraminifera, we demonstrate that successive assessments of sediment microtopography mapping using a three-dimensional (3D) sensor can provide direct and accurate quantifications of meiofaunal SSRR, with high spatial and temporal resolutions. This new method is thus particularly suitable to investigating the as-yet-unknown influence of the meiobenthic fauna, such as foraminifera, on particle transport at the sediment–water interface and more generally on the functioning of benthic soft-bottom ecosystems.
(Journal of Micropalaeontology. vol. 44, n° 0262-821X, pp. 401-413, 08/04/2026)
LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS