Analyse des tendances de contaminations historiques multi-métalliques dans les archives sédimentaires de la Saône (années 1940 - actuel)
In order to understand the evolution of metallic contaminant flux in the Saone River towards Lyon over time, two sediment cores were studied. These cores provide records spanning over 80 years with relatively continuous and homogeneous deposition. Age models were established based on radionuclide profiles (137Cs and 210Pb), defining high deposition rates (1–2 cm. yr⁻¹) that enable to study contaminant trends at high temporal resolution. These analyses reveal distinct contamination phases linked to the industrial history of the basin. Based on the chronology covered by these sediment archives, copper, lead, and cadmium contamination can be identified as early as the 1950s, with peaks extending during the 1970s. Later, while contamination levels of these metals, silver reaches maximal concentrations at two periods, in the 1970s and 1980s, and then during the 1990s. Within the industrial context of the basin, silver contamination can be associated with the photographic industry. These findings show that secondary channels of the Saone River have been affected by multi-metallic contamination accumulated since the 1950s. They act as pollution archives, enabling the reconstruction of the consequences of anthropogenic activities on river ecosystems. Moreover, this stock of metallic contaminants requires integrated management within the framework of secondary channel restoration efforts.
(09/07/2025)
LEHNA, UCBL, ENTPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, EVS, ENS de Lyon, Mines Saint-Étienne MSE, IMT, UL2, UJML, INSA Lyon, INSA, UJM, ENTPE, ENSAL, CNRS, ALLHiS, UJM
Cryosphere and ocean variability in Kane Basin since the 18th century: insights from two marine multi-proxy records
Abstract. Nares Strait, a marine gateway connecting the Arctic Ocean with northern Baffin Bay, is characterised by the formation of a seasonal ice bridge between Canada and Greenland, that prevents the southward export of multiyear sea ice. Recent observations indicate increasing instability in sea-ice formation, particularly evident in Kane Basin, which either freezes over or remains open during winter and spring depending on ice-bridge dynamics. The Kane Basin is influenced by contrasting ocean currents in its eastern and western sides, as well as by the Humboldt Glacier, Greenland’s widest marine-terminating glacier. Kane Basin is a critical region due to its pronounced sensitivity to cryospheric and oceanic changes. However, its long-term environmental history, particularly in the eastern sector, remains poorly constrained prior to the satellite era. Here, we present two multi-proxy sediment core records from opposite sides of Kane Basin, spanning from the 18th century to the present, that we compare with Humboldt Glacier frontal positions since 1965 CE. Clear spatial differences are evident across the basin in terms of sediment delivery, primary productivity, and the source of organic matter. Both records also reveal temporal changes, transitioning from cold sea-surface conditions with extensive sea ice during the Little Ice Age (peaking around 1900 CE), towards more open and stratified waters, accompanied by increased primary production from approximately 1950 CE to the present.
(Climate of the Past Discussions [Climate of the Past Preprints], n° 1814-9340, 08/07/2025)
UCPH, LOCEAN-VOG, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, UVSQ, CEA, INSU - CNRS, X, CNES, SU, CNRS, UPCité, GEUS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, METIS, EPHE, PSL, INSU - CNRS, SU, CNRS, ULaval, INSU - CNRS, CNRS, UNB
Cartographie du Réservoir Utile Maximal en eau des sols à partir des Référentiels Régionaux Pédologiques
Le Réservoir en eau Utilisable (RU) des sols est la quantité d’eau qu’un sol peut retenir et restituer aux plantes. Cet indicateur dépend de la texture du sol, c’est-à-dire des proportions d’argiles, limons et sables, ainsi que de sa profondeur et de sa proportion d’éléments grossiers. La teneur en carbone du sol a également été identifiée comme prédicteur important du RU lorsqu’il est estimé par une fonction de pédotransfert (Román Dobarco et al., 2019). La disponibilité de données sur les sols augmente en France, notamment par l’effort de réalisation des Référentiels Régionaux Pédologiques (RRP) dans le cadre du programme « Inventaire, Gestion et Conservation des Sols » (IGCS) coordonné par le Groupement d’intérêt Scientifique Sol. Ces systèmes d’informations spatialisées sur les sols à l’échelle 1/250 000 présentent une base sémantique riche qui peut être valorisée à travers des cartographies thématiques de propriétés fonctionnelles des sols à l‘échelle régionale. Dans ce contexte, notre étude vise à proposer une procédure pour calculer et cartographier aisément et de façon quasi-automatique le RU à partir d’un RRP, sous la forme d’un un script en langage Python. Afin de minimiser les échecs de calcul dus à d’éventuelles données manquantes, le script implémente un arbre de décisions permettant de compléter la base de données en utilisant d’autres variables pédologiques disponibles ou à dires d’expert. Le script a été testé sur des jeux de données partiellement incomplets afin d’évaluer sa fiabilité en présence de données manquantes. L’application de ce script au RRP de Bretagne a permis de générer des cartes du RU estimé sur une épaisseur de sol de 1 mètre à partir de trois sources de données : (1) la base de données DoneSol du RRP avec une représentation de la valeur du RU par Unités Cartographiques de Sol ; (2) les données issues de la spatialisation des Unités Typologiques de Sol (Vincent et al., 2016) du RRP Bretagne projetées sur une grille raster au pas de 50 mètres et (3) les propriétés pédologiques à la même résolution dérivées par tranche de profondeur selon les spécifications GlobalSoilMap. Les cartes (2) et (3) du RU ont été comparées aux résultats préexistants, dont la carte du RU nationale à une résolution de 90 mètres (Román Dobarco et al. 2021), ainsi que la carte issue des données de SoilGrids. Cette étape rend compte de la pertinence des différents niveaux de précision en fonction des usages de l’information produite. De plus, l’utilisation de données locales exhaustives permet d’obtenir une carte du RU englobant la variabilité induite par les spécificités pédologiques régionales, telles que les sols issus de limons éoliens sur la frange nord de la région et jusqu’au centre de l’Ille-et-Vilaine, ou bien les Monts d’Arrée en Bretagne, dans le Finistère. Enfin, ce script offre une valorisation rapide et accessible des données des RRP, que l’on peut déployer à l’échelle d‘autres régions. La démarche employée dans notre étude ouvre également des perspectives quant à la complétion des bases de données, et au calcul de nouveaux indicateurs de qualité des sols.
(07/07/2025)
SAS, INRAE, Institut Agro, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, Bordeaux Sciences Agro
OntoPFAS : Ontologie des PFAS et de leur exposition
La construction d'ontologies est une des premières tâches dans le domaine de la représentation des connaissances. Elle reste très pertinente aujourd'hui, grâce à l'expressivité des langages formels, qui permettent encore d'explorer et de découvrir des connaissances. Pendant des décennies, la communauté a développé des méthodologies pour la construction manuelle d'ontologies, et plusieurs classifications de celles-ci ont été proposées. Dans cet article, nous présentons une méthodologie de construction d'ontologie basée sur des méthodes existantes, et nous l'appliquons à la représentation du domaine des PFAS (Per-et poly-fluoroalkyle substances) et de leur exposition. Les PFAS sont des substances dont la structure chimique particulière les rend très résistantes et efficaces dans de nombreuses applications industrielles. Ils suscitent un intérêt croissant en raison de leur impact négatif sur la santé et l'environnement. Ce travail s'inscrit dans le cadre du projet interdisciplinaire DAE (Détection d'Anomalies Environnementales).
(pp. 7 p., 02/07/2025)
MISTEA, INRAE, Institut Agro, LIB, UBE, LIRMM | ADVANSE, LIRMM, UPVD, Inria, CNRS, UM, UMPV, PRODIG (UMR_8586 / UMR_D_215 / UM_115), UP1, IRD, SU, CNRS, UPCité, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Effects of Microplastic-Sediment Interactions on Microplastics Dispersion in the Gironde Estuary: A Modelling Approach
(01/07/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UPPA, Cerema Direction Est, Cerema
The ecology of live bathyal benthic foraminifera on the southern and southeastern Australian Margin
Living (Rose Bengal stained) benthic foraminifera were examined in multicore samples collected at depths ranging from 580 to 1,270 m from the Tasman Sea and southern margin of Australia. This study presents an initial overview of the deep-sea foraminifera living on these margins. Based on widely separated cores, there appears to be no correlation between foraminiferal abundance and species with ocean depth, seafloor grain size, oxygen availability, temperature, or particulate organic carbon. Although more work is needed, this study suggests environmental factors affect foraminiferal populations in a complex manner in the study area. The presence of species typical of shelf and shallow water environments in cores collected below 200 m water depth suggests a possible redistribution from shallower areas. In the ten samples from the 0–1 cm interval for the >150 ?m size fraction, 37 unique species were found. No more than four species overlapped across sites. Surprisingly, no significant correlations were observed between cosmopolitan foraminifera (i.e., Cibicidoides bradyi, Cibicidoides mundulus, Globobulimina subglobosa, Hoeglundina elegans, Uvigerina asperula, and Melonis affinis) and environmental parameters. Considerable environmental heterogeneity between sample sites, such as oxygen availability, grain size, and other factors associated with ocean circulation, is clearly evident. Based on observed assemblages, foraminiferal populations in the region appear influenced by dynamic and heterogeneous seafloor environments. This study serves as one of the few investigations of its kind to examine the ecology and diversity of contemporary deep-sea benthic foraminiferal communities along the southern and southeastern Australian margin, and highlights the potential ecological impacts of the heterogeneity and complexity of seafloor environments in the region. Additional work is necessary to further test and evaluate these hypotheses, and this research provides a foundation for future observations of living benthic foraminifera in the region.
(Micropaleontology. vol. 71, n° 0026-2803, pp. 307-334, 01/07/2025)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, RSES, ANU
Integrative taxonomy reveals further hidden diversity of Marphysa (Polychaeta: Eunicidae) in European Atlantic and Mediterranean waters
Abstract Marphysa (Polychaeta: Eunicidae) is represented in the Mediterranean by M. aegypti, M. birgeri, and M. chirigota. Previous reports of M. sanguinea are doubtful, because it has a confirmed distribution around the southern English coasts (NE European Atlantic). In this study, we combine morphological and molecular (using 16S rDNA and cytochrome c oxidase I) analyses to reveal for the first time the presence of M. gaditana in the NW Mediterranean (Gulf of Tunis, Tunisia) and to substantiate its presence along the Atlantic coasts of France—previously relying solely on molecular data—drawing on specimens collected in Arcachon Bay and Oléron Island. Our findings also allow us to describe a new species of Marphysa from the Mediterranean coasts of southern France, namely Marphysa gili Martin and Romano, sp. nov., based only on morphological data. Our research highlights previously overlooked diversity within Marphysa on Atlantic and Mediterranean European coasts, thus contributing to the growing series of recent rigorous taxonomic studies that are challenging the historical tendency to merely report ‘M. sanguinea’ without a thorough taxonomic examination or when undertaking physiological, reproductive, or resource management studies on ‘M. sanguinea’ without questioning the appropriateness of using this species’ name.
(Zoological Journal of the Linnean Society. vol. 204, n° 0024-4082, 01/07/2025)
CEAB, CSIC, UTM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMS POREA, INSU - CNRS, CNRS, INRAE, LIENSs, INSU - CNRS, ULR, CNRS, OBIONE, LIENSs, INSU - CNRS, ULR, CNRS
A Weakened AMOC Could Cause Southern Ocean Temperature and Sea‐Ice Change on Multidecadal Timescales
We present the first CMIP6-era multi-model intercomparison of the Southern Ocean (SO) temperature and sea-ice response to substantial Atlantic meridional overturning circulation (AMOC) weakening. Results are based on analysis of the North Atlantic Hosing Model Intercomparison Project, involving eight CMIP6 models under identical North Atlantic freshwater hosing. On multidecadal timescales, we find that southwards ocean heat transport into the SO increases, causing surface warming and sea-ice loss. Additionally, an atmospheric tropical-Antarctic teleconnection, identified here for the first time, causes regional temperature and sea-ice changes in the SO. Unlike previous studies, we find that the Amundsen Sea Low deepens for only some models. Overall, in the multi-model ensemble mean (multi-model range in brackets), over years 50-100 after AMOC weakening: SO surface air temperature warms by 0.3 (0.1-0.7)°C, sea level pressure (SLP) decreases by 30 (10-70) Pa, and sea-ice area decreases by 0.4 ( 0.2-1.3) Mkm 2 . The teleconnection leads to regional differences between the response in the Indian sector and the Weddell Sea of 180 (80-320) Pa in SLP, 0.6 (0.5-1.4)°C in surface air temperature, and 0.1 (0.1-0.2) Mkm 2 in sea-ice area. These SO heat transport, temperature, pressure, and sea-ice changes are small relative to the changes expected under future anthropogenic warming, despite the large and idealized 0.3 Sv hosing used to weaken the AMOC.
(Journal of Geophysical Research. Oceans. vol. 130, n° 2169-9275, pp. e2024JC022027, 01/07/2025)
CAM, UOR, BAS, NERC, NCAR, MPI-M, UCM, CCCma, ECCC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Near Steady Late Pleistocene Tropical Denudation Rates in SW Madagascar
Denudation is a key parameter controlling the evolution of the Earth's surface, the production of soils, the stability of relief, or the long‐term evolution of climate. Climate fluctuations conversely have a strong impact on denudation, but these complex feedback mechanisms are still under‐constrained. To better predict future changes that will affect our habitat and understand the links between climate and denudation, precise quantification of paleo‐denudation rates is required. In this work, we measure cosmogenic radionuclides (10Be) in turbidites of a well‐dated marine sedimentary core recovered in the Mozambique Channel to provide a 900‐ka long near‐continuous record of paleo‐denudation rates over the 100‐ka climatic cycles. Neodymium isotopes and heavy mineral analysis were used to provide constraints on the provenance of terrigenous sediments exported from Madagascar to the studied site and show that temporal variations in sediment provenance are limited and decoupled from climatic cyclicity. Our 10Be‐based paleo‐denudation rates are in the same order as modern rates, ranging from 17.4 ± 5.8 mm/ka to 73.9 ± 29.4 mm/ka (1 standard deviation), and do not show major variations through the Middle and Late Pleistocene. Importantly, we did not identify a systematic significant impact of glacial/interglacial cyclicity on denudation rates. Denudation of this subtropical island may instead have been controlled by variability of monsoon intensity associated with shifts in the Inter Tropical Convergence Zone, but this interpretation remains speculative at this stage as it cannot be recorded within the resolution of cosmogenic‐derived denudation rates.
(Journal of Geophysical Research: Earth Surface. vol. 130, n° 2169-9003, pp. e2024JF008147 (32p.), 01/07/2025)
CRPG, INSU - CNRS, UL, CNRS, GEO-OCEAN, UBS, IFREMER, INSU - CNRS, UBO EPE, CNRS, UNIMIB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Drivers of Water Mass Volume Changes in the Nordic Seas (2005–2020)
The Nordic Seas are integral parts of the Atlantic meridional overturning circulation and a key region for the global climate. In this study, we combine observational products, largely derived from the Argo array, to examine the changes affecting ocean conditions in the different regions of the Nordic Seas from 2005 to 2020. Significant warming and deepening of isopycnal surfaces have been found across all regions since 2013, resulting in a volume increase of the surface layer above the σ0 < 27.8 kg m−3 isopycnal. A volume budget over three isopycnal layers is built to disentangle the relative roles played by the atmospheric forcing that results in local water mass transformation and large‐scale advection. In eastern basins, an increase in both the advection of Atlantic water and surface water mass transformation led to an expansion of the surface layer after 2012. In contrast, changes found in the Greenland Sea result primarily from a decrease in transport convergence and changes in the surface forcing that ventilates all layers of the region. Our analysis also highlights that an improved sampling of the region, including toward greater depths and on the East Greenland shelves, is required to reduce uncertainties in the water mass transformation budget of the Nordic Seas and to better understand the mechanisms at play.
(Journal of Geophysical Research. Oceans. vol. 130, n° 2169-9275, pp. e2024JC022209 (16p.), 01/07/2025)
LOPS, IRD, IFREMER, INSU - CNRS, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS