Holocene glacier and deep water dynamics, Adélie Land region, East Antarctica
This study presents a high-resolution multi-proxy investigation of sediment core MD03-2601 and documents major glacier oscillations and deep water activity during the Holocene in the Adé lie Land region, East Antarctica. A comparison with surface ocean conditions reveals synchronous changes of glaciers, sea ice and deep water formation at Milankovitch and sub-Milankovitch time scales. We report (1) a deglaciation of the Adé lie Land continental shelf from 11 to 8.5 cal ka BP, which occurred in two phases of effective glacier grounding-line retreat at 10.6 and 9 cal ka BP, associated with active deep water formation; (2) a rapid glacier and sea ice readvance centred around 7.7 cal ka BP; and (3) five rapid expansions of the glacier-sea ice systems, during the Mid to Late Holocene, associated to a long-term increase of deep water formation. At Milankovich time scales, we show that the precessionnal component of insolation at high and low latitudes explains the major trend of the glacier-sea ice-ocean system throughout the Holocene, in the Adé lie Land region. In addition, the orbitally-forced seasonality seems to control the coastal deep water formation via the sea ice-ocean coupling, which could lead to opposite patterns between north and south high latitudes during the Mid to Late Holocene. At sub-Milankovitch time scales, there are eight events of glacier-sea ice retreat and expansion that occurred during atmospheric cooling events over East Antarctica. Comparisons of our results with other peri-Antarctic records and model simulations from high southern latitudes may suggest that our interpretation on glacier-sea ice-ocean interactions and their Holocene evolutions reflect a more global Antarctic Holocene pattern.
(Quaternary Science Reviews. vol. 28, n° 0277-3791, pp. 1291-1303, 28/05/2026)
UP1, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, VU, PBDS, INSU - CNRS, CNRS, LMGM, CNRS, CBI, UT3, Comue de Toulouse, CNRS
Benthic geochemistry of manganese in the Bay of Biscay, and sediment mass accumulation rate
Manganese is a major redox reactive element of benthic metabolism. We have built a database of existing knowledge on the benthic geochemistry of Mn in the Bay of Biscay, in order to comprehensively assess the behaviour of Mn in a variety of environments during early diagenesis. The database contains vertical profiles of particulate and dissolved Mn species of 59 cores collected during 17 cruises between 1997 and 2006 at nine stations positioned between 140 and 4,800 m water depths. At all studied stations, Mn species follow the conventional distribution, where Mn(III,IV) species are enriched in the oxic layer, and dissolved Mn is present in the anoxic sediments. A minor part of Mn-oxides originates from sedimenting particles. The major part is of diagenetic origin, and derives from the oxidation of upward-diffusing dissolved Mn(II). Mn-oxide inventories are higher at the deeper stations than at the shallower ones. This difference cannot be attributed to different sources of sedimenting particles, but it must depend on sedimentation rate and diagenetic processes. At depth, dissolved Mn(II) concentrations are constant. This probably reflects equilibrium with an authigenic Mn(II) phase, which is the ultimate phase into which Mn is fossilized. The Mn content of deeper anoxic sediments is similarly low in all the cores studied, associated with corresponding trends of Mn content in sedimenting particles of the Bay of Biscay. Bioturbation, rather than redox oscillations, can convey Mn(III,IV) species downwards into the anoxic sediments where they are reduced, associated with a peak of dissolved Mn. Because dissolved Mn(II) is re-oxidized when it diffuses towards the oxic layer, the inventory of the diagenetic Mn(III,IV) phase remains at steady state, especially at stations where the oxic layer is thick. It then becomes possible to calculate the residence time of diagenetic Mn(III,IV) particles within the oxic layer, using the upward-directed flux of pore water Mn(II). By applying this residence time to the accumulation of sediments within the oxic layer, we obtain the sediment mass accumulation rate. The values calculated for the sediments of the Bay of Biscay fit well with accumulation rates obtained from radionuclides or sediment traps. The method has also been validated with data collected in other marine sedimentary environments.
(Geo-Marine Letters. vol. 29, n° 0276-0460, pp. 133-149, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPGN, UN, CNRS, IPGP - UMR_7154, INSU - CNRS, IGN, UR, IPG Paris, CNRS, UPCité
New core-top Mg/Ca calibration of multiple benthic foraminiferal species: Thermometry of the thermocline water in tropical western Atlantic
(. vol. 11, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UiB, BCCR, BIO / UiB, UiB, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LPGN, UN, CNRS
Des biofilms témoins et acteurs du fonctionnement de la rivière
Des biofilms phototrophes complexes (multi espèces) se développent dans certains tronçons de rivière. Ils participent au fonctionnement de la rivière et peuvent être utilisés comme bioindicateurs pour la gestion des cours d'eau.
(pp. 3, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CNRS, UR REBX, CEMAGREF
Treatment of topographic and bathymetric data acquired at the Truc-Vert Beach (SW France) during the ECORS field experiment
(. vol. special issue 56, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BRGM, L3AB, UB, INSU - CNRS, CNRS, OASU, UB, INSU - CNRS, ULR, CNRS, INRAE, LAB, UB, INSU - CNRS, CNRS, UB
La dimension biogéographique de l'évolution de la Vie.
Le rôle de la composante biogéographique dans les mécanismes de l’évolution biologique fait l’objet de discussions entre les évolutionnistes. Dans ce travail, les idées de Darwin dans le contexte de la biogéographie sont discutées après avoir rappelé le rôle de l’élément géographique dans les processus de spéciation et résumé les notions de base et les modèles théoriques classiques de la biogéographie. Le modèle de Darwin, ou de la dispersion à partir d’un « centre d’origine », fut proposé lorsque les preuves de la mobilité continentale n’étaient pas encore concluantes. Le modèle de la vicariance, qui s’oppose à celui de la dispersion, est maintenant soutenu par la dérive continentale et l’expansion des fonds océaniques. Ces deux modèles classiques de la biogéographie pourraient s’appliquer dans les cas de convergence et divergence biogéographique, en relation avec des changements paléogéographiques
(Comptes Rendus. Palevol. vol. 8, n° 1631-0683, pp. 119-132, 28/05/2026)
CR2P, MNHN, UPMC, CNRS
Sensory organs of Archaeostraca (Phyllocarida, Crustacea).
(Evolution & Development. vol. 11, n° 1525-142X, pp. 225-232, 28/05/2026)
CR2P, MNHN, UPMC, CNRS, LDO, INSU - CNRS, UBO EPE, CNRS
Erosion and impact of human disturbance on sediment transport in the Red River, Vietnam
Mechanical erosion and sediment transfers depend strongly on many natural parameters related to topography, climate and land cover [1]. Additionally, anthropogenic activities may affect sediment supplies to estuaries, deltas and the coastal zone [2]. The Red River (China/Vietnam, A=155 000 km²) is a typical tropical humid river originating from the mountainous area of the Yunnan Province in China. Based on daily discharges (Q) and suspended particulate matter (SPM) concentrations between 1960-2007 at SonTay gauging station (outlet of the river and entry to the Delta) provided by the national institute IMHE-MONRE, the mean annual SPM fluxes was estimated to 90 Mt/yr, corresponding to a sediment yield of 600 t/km²/yr, similar to the Ganges/Brahmaputra system [3], and probably due to same controlling factors. The temporal variability of annual SPM fluxes (ranging from 24 to 200 Mt/yr) is strongly related to the interannual hydrological conditions. However, some years of high water flow did not account for high sediment fluxes, especially after 1989 when the HoaBinh dam was operated. Sediment rating curves (power law-type; SPM=aQb) were fitted for both periods (1960-1989; 1990-2007). The analysis of the pre- and post-1989 sediment rating parameters (a, b) suggests a downshift of a-parameter values after 1989, attributed to decreased sediment supply [4]. A single sediment rating curve derived from 1960-1989 data was used to simulate the annual variability of former sediment delivery, generating excellent cumulative flux estimates (error <-5%). In contrast, applying the same rating curve to the 1986-2007 data resulted in systematic, important (up to 97%) overestimation. This suggests that the HoaBinh dam reduces annual SPM delivery to the delta by half, implying changes in nutrient and contaminant transport.
(Geochimica et Cosmochimica Acta. vol. 13, n° 0016-7037, pp. A260, 28/05/2026)
Bioemco, ENS-PSL, PSL, IRD, INRA, UPMC, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IWMI-SEA, IWMI, CGIAR, SFRI, VAAS, ICH/VAST
New outcomes from spatial remote sensing during the ECORS experiment : towards validation of ocean color products and large-scale bathymetry mapping in a coastal zone
(Journal of Coastal Research, n° 0749-0208, pp. SI56(2), 1756-1760, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CRC, UB, CNRS
Millennial-scale climatic variability between 340 000 and 270 000 years ago in SW Europe: evidence from a NW Iberian margin pollen sequence
We present a new high-resolution marine pollen record from NW Iberian margin sediments (core MD03-2697) covering the interval between 340 000 and 270 000 years ago, a time period centred on Marine Isotope Stage (MIS) 9 and characterized by particular baseline climate states. This study enables the documentation of vegetation changes in the northwestern Iberian Peninsula and therefore the terrestrial climatic variability at orbital and in particular at millennial scales during MIS 9, directly on a marine stratigraphy. Suborbital vegetation changes in NW Iberia in response to cool/cold events are detected throughout the studied interval even during MIS 9e ice volume minimum. However, they appear more frequent and of higher amplitude during the 30 000 years following the MIS 9e in-terglacial period and during the MIS 9a-8 transition, which correspond to intervals of an intermediate to high ice volume and mainly periods of ice growth. Each suborbital cold event detected in NW Iberia has a counterpart in the Southern Iberian margin SST record. High to moderate amplitude cold episodes detected on land and in the ocean appear to be related to changes in deep water circulation and probably to iceberg discharges at least during MIS 9d, the mid-MIS 9c cold event and MIS 9b. This work provides therefore additional evidence of pervasive millennial-scale climatic variability in the North Atlantic borderlands throughout past climatic cycles of the Late Pleistocene, regardless of glacial state. However, ice volume might have an indirect influence on the amplitude of the millennial climatic changes in Southern Europe.
(Climate of the Past. vol. 5, n° 1814-9324, pp. 53-72, 28/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, WHOI, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA