Drones souterrains, inspection et imagerie 3D : contraintes et potentialités d’un nouvel outil de documentation des grottes et du karst
Les drones ont connu, au cours des dernières années, une forte diversification de leurs usages. La réduction du poids des engins et la diminution des coûts concourent à ces développements. En grotte, l’usage des drones est limité par l’altération des capteurs d’assistance au télépilotage : GNSS, vision, capteurs d’évitement, centrale inertielle. Le télépilote doit alors conduire la mission avec le double objectif de maintenir l’intégrité de la machine, de la grotte et des personnels, tout en assurant une captation correcte des données. Un test de photogrammétrie 3D, conduit dans la grotte Sainte-Catherine (Ariège) montre un résultat satisfaisant et confirme l’intérêt des drones dans les constructions de modèles 3D en grotte. Les conditions du pilotage, les conditions d’acquisition des données et les potentialités futures sont discutées.
(Karstologia, n° 0751-7688, pp. 1-8, 11/04/2026)
EDYTEM, USMB [Université de Savoie] [Université de Chambéry], CNRS, Fédération OSUG, ISTerre, IRD, INSU - CNRS, USMB [Université de Savoie] [Université de Chambéry], CNRS, Fédération OSUG, UGA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, INSU - CNRS, CNRS, UA, UM, IDEES, UNICAEN, NU, ULH, NU, UNIROUEN, NU, CNRS, IRIHS, UNIROUEN, NU
Monitoring the Temporal Evolution of the Floods in the Lower Mekong Basin using Multisatellite Observations
Surface water storage is an essential component of the hydrological cycle. Remote sensing offers valuable tools for monitoring both surface water extent from satellite images and water levels from radar altimetry. Combining both information, we were able to estimate the variations of surface water extent and storage in the Lower Mekong Basin from 2000 to 2020. Signatures of the extreme climatic events - floods from 2000 to 2002, of 2011, drought of 2015 clearly appear on both extent and storage. The mean amplitude of these variables shows a strong decrease when comparing the periods of 2000–2010 and 2011–2020. Between these two periods, a large reduction of the annual average number of days with the presence of floods can be observed in most of the Lower Mekong Basin, except around the Tonle Sap (Cambodia) and in some parts of the delta.
(pp. 5877-5880, 11/04/2026)
UMR ISPA, Bordeaux Sciences Agro, INRAE, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, OASU, UB, INSU - CNRS, ULR, CNRS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, USTH, LERMA, ENS-PSL, PSL, INSU - CNRS, CNRS, PSL, SU, CNRS, CY, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS
Inertia of parasite infection versus host biomass fluctuation.
Infection by parasites with complex life cycles such as trematodes depends on many environmental factors which may result in a time-lag between host biomass fluctuations and parasite density in hosts. A cockle (marine bivalve, second intermediate host) population and its associated parasite community were monitored over 15 years. A time-shift correlation analysis suggests that trematode abundance in cockles responds to cockle biomass after a long delay (8 year time-lag). Thus, these parasites can sustainably support a deficit of their intermediate host.
(International Journal for Parasitology. vol. 53, n° 0020-7519, pp. 65-68, 11/04/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Sur quelques curiosités d'histoire naturelle dans les pertuis charentais : faune des invertébrés marins
Huit espèces redécouvertes, en expansion démographique ou nouvelles sont signalées dans les Pertuis Charentais. Elles sont issues d’habitats rocheux intertidaux (Alpheus macrocheles, Aslia lefevrei, Epitonium clathrulatum et Haliotis tuberculata), meubles intertidaux (Africorchestia spinifera et Arcuatula senhousia) et subtidaux (Aslia lefevrei et Rapana venosa) voire pélagiques (Lepas anatifera). Ces espèces sont, sauf exceptions, dans leur aire de répartition géographique naturelle. Natif de l’Asie du Nord-Est, le gastéropode R. venosa a été introduit depuis les années 2010 dans les pertuis et y connait actuellement une notable expansion démographique. L’île de Ré est définie comme la nouvelle limite nord de la distribution atlantique de l’amphipode Africorchestia spinifera. La phorésie de Crepidula fornicata sur Carcinus maenas est notée mais était déjà connue en Europe alors que pour R. venosa elle est nouvelle pour la science. Elle met en jeu une association incredibile dictu entre deux espèces déplacées hors de leurs aires natives par les activités maritimes et/ou aquacoles.
(Annales de la Société des Sciences naturelles de Charente-Maritime. vol. 11, n° 0373-9929, pp. 533-548, 11/04/2026)
LIENSs, INSU - CNRS, ULR, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LERAR, COAST, IFREMER, PatriNat, MNHN, IRD, CNRS, OFB - DSUED, OFB, LEMAR, IRD, IFREMER, UBO EPE, CNRS, LERPC, COAST, IFREMER, OBIOS
High contamination of a sentinel vertebrate species by azoles in vineyards: a study of common blackbirds (Turdus merula) in multiple habitats in western France
Azoles represent the most used family of organic fungicides worldwide and they are used in agriculture to circumvent the detrimental impact of fungi on yields. Although it is known that these triazoles can contaminate the air, the soil, and the water, field data are currently and dramatically lacking to assess if, and to what extent, the use of triazoles could contaminate non-target wild vertebrate species, notably in agroecosystems. In this study, we aimed to document for the first time the degree of blood contamination of a generalist wild bird species by multiple azoles which are used for plant protection and fungi pest control in various habitats. We deployed passive air samplers and captured 118 Common blackbirds (Turdus merula) in an agroecosystem (vineyard), a protected forest, and a city in western France. We collected blood and analyzed the plasma levels of 13 triazoles and 2 imidazoles. We found that a significant percentage of blackbirds living in vineyards have extremely high plasma levels of multiple azoles (means (pg.g⁻¹); tebuconazole: 149.23, difenoconazole: 44.27, fenbuconazole: 239.38, tetraconazole: 1194.16), while contamination was very limited in the blackbirds from the protected forest and absent in urban blackbirds. Interestingly, we also report that the contamination of blackbirds living in vineyard was especially high at the end of Spring and the beginning of Summer and this matches perfectly with the results from the passive air samplers (i.e., high levels of azoles in the air of vineyards during June and July). However, we did not find any correlation between the levels of plasma contamination by azoles and two simple integrative biomarkers of health (feather density and body condition) in this sentinel species. Future experimental studies are now needed to assess the potential sub-lethal effects of such levels of contamination on the physiology of non-target vertebrate species.
(Environmental Pollution. vol. 316, n° 0269-7491, pp. 120655, 11/04/2026)
CEBC, ULR, CNRS, INRAE, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Paleoflora y Paleovegetación Ibérica III: Holoceno
(pp. 1095, 30/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, EPHE, PSL, CNRS, UM, IMBE, AU, AMU, CNRS
Development of a Model to Estimate the Risk of Emission of Greenhouse Gases from Forest Fires
While the Mediterranean basin is foreseen to be highly affected by climate change (CC) and severe forest fires are expected to be more frequent, international efforts to fight against CC do not consider forest fires' greenhouse gas (GHG) emissions risk and the possibility of its mitigation. This is partly due to a lack of a methodology for GHG risk spatial assessment and consideration of the high value of carbon stocks in forest ecosystems and their intrinsic risk. To revert this, an innovative GHG emission risk model has been developed and implemented in a pilot forest area. This model considers geospatial variables to build up emission vulnerability based on potential fire severity and resistance of a landscape, value at risk and the hazard of a fire occurrence. The results classify low, moderate and high emission risks in the analysed areas. This identification of hotspots allows the prioritisation of fire prevention measures in a region to maximise the reduction of GHG emissions in the case of a fire event. This constitutes the first step in a holistic and consistent CC mitigation that not only considers anthropic GHG sources but also possible GHG emissions by forest fires that can be actively prevented, managed and reduced.
(Fire. vol. 6, n° 2571-6255, pp. 8, 29/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Volcanism and tectonics unveiled in the Comoros Archipelago between Africa and Madagascar
Geophysical and geological data from the North Mozambique Channel acquired during the 2020–2021 SISMAORE oceanographic cruise reveal a corridor of recent volcanic and tectonic features 200 km wide and 600 km long within and north of Comoros Archipelago. Here we identify and describe two major submarine tectono-volcanic fields: the N’Droundé province oriented N160°E north of Grande-Comore Island, and the Mwezi province oriented N130°E north of Anjouan and Mayotte Islands. The presence of popping basaltic rocks sampled in the Mwezi province suggests post-Pleistocene volcanic activity. The geometry and distribution of recent structures observed on the seafloor are consistent with a current regional dextral transtensional context. Their orientations change progressively from west to east (»N160°E, »N130°E, »EW). The volcanism in the western part appears to be influenced by the pre-existing structural fabric of the Mesozoic crust. The 200 km wide and 600 km-long tectono-volcanic corridor underlines the incipient Somalia–Lwandle dextral lithospheric plate boundary between the East-African Rift System andMadagascar.
(Comptes Rendus. Géoscience. vol. 354, n° 1631-0713, pp. 1-28, 19/12/2022)
BRGM, iSTeP, INSU - CNRS, SU, CNRS, LMV, IRD, INSU - CNRS, CNRS, UCA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGSR, UR, IPG Paris, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS, IPGP - UMR_7154, INSU - CNRS, IGN, UR, IPG Paris, CNRS, UPCité, ITES, ENGEES, UNISTRA, INSU - CNRS, CNRS, GEO-OCEAN, UBS, IFREMER, INSU - CNRS, UBO EPE, CNRS, GM, IFREMER, GET, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, IPGS, UNISTRA, INSU - CNRS, CNRS, IPGP, INSU - CNRS, UPD7, UR, IPG Paris, CNRS, LGENS, INSU - CNRS, CNRS, ENS-PSL, PSL, BGR, LOG, INSU - CNRS, ULCO, CNRS, IRD [Ile-de-France], EOST, UNISTRA, INSU - CNRS, CNRS, GEOAZUR 7329, INSU - CNRS, UniCA, CNRS, IRD [Occitanie], UniCA
PHANGS-JWST first results: spurring on star formation: JWST reveals localized star formation in a spiral arm spur of NGC 628
We combine JWST observations with Atacama Large Millimeter/submillimeter Array CO and Very Large Telescope MUSE Hα data to examine off-spiral arm star formation in the face-on, grand-design spiral galaxy NGC 628. We focus on the northern spiral arm, around a galactocentric radius of 3–4 kpc, and study two spurs. These form an interesting contrast, as one is CO-rich and one CO-poor, and they have a maximum azimuthal offset in MIRI 21 μm and MUSE Hα of around 40° (CO-rich) and 55° (CO-poor) from the spiral arm. The star formation rate is higher in the regions of the spurs near spiral arms, but the star formation efficiency appears relatively constant. Given the spiral pattern speed and rotation curve of this galaxy and assuming material exiting the arms undergoes purely circular motion, these offsets would be reached in 100–150 Myr, significantly longer than the 21 μm and Hα star formation timescales (both < 10 Myr). The invariance of the star formation efficiency in the spurs versus the spiral arms indicates massive star formation is not only triggered in spiral arms, and cannot simply occur in the arms and then drift away from the wave pattern. These early JWST results show that in situ star formation likely occurs in the spurs, and that the observed young stars are not simply the "leftovers" of stellar birth in the spiral arms. The excellent physical resolution and sensitivity that JWST can attain in nearby galaxies will well resolve individual star-forming regions and help us to better understand the earliest phases of star formation.
(The Astrophysical Journal Letters. vol. 941, n° 2041-8205, pp. L27, 16/12/2022)
UAB, OSU, MPIA, ESO, AlfA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UniCA, LAGRANGE, UNS, INSU - CNRS, UniCA, CNRS, UniCA, LAM, AMU, INSU - CNRS, CNES, CNRS, CRAL, ENS de Lyon, UCBL, INSU - CNRS, CNRS, ANU, CALTECH, Larefi, UB, IRAM, INSU - CNRS, CNRS, LERMA (UMR_8112), INSU - CNRS, CNRS, PSL, UCP, SU, CNRS, UC San Diego, UC
Etude de l’évolution de particules atmosphériques uniques en lévitation : application à la qualité de l’air et au changement climatique
L’objectif de la thèse était d’étudier le vieillissement des aérosols organiques secondaires (AOS) à l’échelle de la particule individuelle. Cet objectif s’inscrit pleinement dans le besoin urgent de combler notre manque de connaissances sur les voies de formation et de devenir atmosphérique des AOS. La lévitation acoustique est une technique expérimentale qui permet de s’affranchir de l’influence du support pour l’étude des propriétés physico-chimiques d’une particule atmosphérique. Le couplage d’un dispositif de lévitation acoustique avec la spectroscopie vibrationnelle nous a permis d’obtenir des informations sur la composition et les états de mélange chimiques des particules. Enfin, le développement d’un couplage de la spectrométrie de masse (PTR-TOF-MS) au dispositif de lévitation acoustique a permis l’analyse de la phase gazeuse dans la cellule de lévitation. In fine, ces développements instrumentaux nous permettent de suivre les modifications des phases particulaire et gazeuse en temps réel afin d’avoir une meilleure compréhension des mécanismes de vieillissement des aérosols. Nous nous sommes notamment intéressés dans cette thèse aux processus d’évaporation et aux propriétés d’hygroscopicité de particules de mélanges AOS/sels. L’influence de la composition chimique et de l’état de mélange de la particule sur ces processus a été mise en évidence. Les résultats obtenus confirment la complexité des propriétés chimiques des aérosols qui influent directement et indirectement sur le changement climatique au niveau global.
(14/12/2022)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS