SPCZ migration and ENSO events during the 20th century as revealed by climate proxies from a Fiji coral
Instrumental sea surface temperature (SST) and sea surface salinity (SSS) records since 1975 have indicated that migrations of the South Pacific Convergence Zone (SPCZ) are strongly related to El Niño-Southern Oscillation (ENSO) events. To reconstruct independent SSS and SST time series for the past century and document this SPCZ and ENSO relationship prior to 1975, we apply a neural network analysis to seven climate proxies derived from a coral skeleton collected in Fiji. These reconstructions suggest that five SPCZ migrations linked to ENSO occurred between 1908 and 1970 while as many migrations occurred during the last three decades, highlighting the recent enhanced frequency of ENSO occurrence.
(Geophysical Research Letters. vol. 33, n° 0094-8276, pp. L17710, 26/08/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LOCEAN, IPSL, ENS-PSL, PSL, UVSQ, UPMC, CEA, INSU - CNRS, X, IP Paris, CNES, CNRS, MNHN, IRD, UPMC, INSU - CNRS, CNRS, ESTIMR, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, PALEOTROPIQUE
Significance of vertical flux as a sink for surface water DMSP and as a source for the sediment surface in coastal zones of northern Europe
(Estuarine, Coastal and Shelf Science. vol. 68, n° 0272-7714, pp. 473-488, 26/08/2026)
LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, ICOS-RAMCES, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, LEMAR, IRD, IFREMER, UBO EPE, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Three-dimensional densitometry imaging of diatom cells using STIM tomography
Scanning transmission ion microscopy tomography (STIM-T) was carried out on diatom cells with the aim of displaying their 3D structure and performing density measurements on their silica skeleton. Two software packages were compared for data reduction: TomoRebuild, based on a simple filtered backprojection algorithm, and DISRA, an iterative program. Silicon carbide microfibres of known density were also analysed as reference specimens. Similar results were obtained with both algorithms, demonstrating the ability of STIM-T to provide density measurements at the cell level without requiring any standard calibration samples. This unique feature stresses the interest of STIM-T to accurately normalise X ray emission micro-tomography data from synchrotron radiation (SXRF: synchrotron radiation X-ray fluorescence) or ion beam sources (PIXE: particle induced X-ray emission). Possible enhancements of the DISRA code are discussed in order to facilitate its use for the reconstruction of future PIXE/STIM tomography data. A “nanoprobe” coupled to a Singletron® accelerator, allowing a spatial resolution of a few tens of nanometers, is going to be built in the coming months at the Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG). This new facility will bring promising applications in imaging and analysis at the sub-cellular level.
(. vol. 249, pp. 653-659, 26/08/2026)
CENBG, UB, IN2P3, CNRS, CNAB, UB, CNRS, LST, ENS de Lyon, UCBL, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LCTS, UB, CEA, INC-CNRS, CNRS
Fifty-year sedimentary record of heavy metal pollution in the lagoon of Oualidia (Moroccan Atlantic coast)
The Oualidia lagoon is known for its heavy metal pollution resulting from mining and smelting activities since the late 19th century. Here, we report 137Cs and 210Pb activities and heavy metal concentration depth profiles from sediment cores retrieved in 1997. High mean sedimentation rates of 0.6e1 cm/y are indicated by 210Pb and 137Cs dating. The lagoon sediments have recorded heavy metal deposition and thus allow establishment of a connection between the temporal evolution of the heavy metal pollution and historical changes in smelting and waste-treatment proceedings. Through a study of the evolution of heavy metal contents, we can distinguish between two categories of metals: 1- Al, Fe and Cr contents have varied around a mean value over the last seven decades and could have natural origins. 2- Pb, Zn, Cu and Hg have relatively more elevated contents than those of the natural geochemical background, especially in the station in front of illegal sewerage discharges. These metals are enriched at depths between 20 and 30 cm; this corresponds to the period between 1960 and 1975, which was characterized by the setting up of the main suburbs and the first aquaculture farms that surround the lagoon. The pollution intensity of the lagoon is determined by enrichment factors and the geo-accumulation index, which show that the lagoon of Oualidia is unpolluted to moderately polluted on the Geo-I scale of Müler (1979).
(Estuarine, Coastal and Shelf Science. vol. 72, n° 0272-7714, pp. 359-369, 26/08/2026)
LETG - Nantes, UNICAEN, NU, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Courants induits et dissipation de l'énergie des vagues sur les plages macrotidales de la mer d'Iroise
(26/08/2026)
LETG - Brest, LETG, UNICAEN, NU, UA, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN, NU, UNIROUEN, NU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Cadmium transport in sediments by tubificid bioturbation: an assessment of model complexity.
(Geochimica et Cosmochimica Acta. vol. 71, n° 0016-7037, pp. 844 - 862, 26/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEH, UT3, Comue de Toulouse, CNRS
A fourth-order compact finite volume scheme for fully nonlinear and weakly dispersive Boussinesq-type equations. Part I: Model development and analysis
A high‐order finite volume scheme is developed to numerically integrate a fully nonlinear and weakly dispersive set of Boussinesq‐type equations (the so‐called Serre equations) (J. Fluid Mech. 1987; 176:117–134; Surveys Geophys. 2004; 25(3–4):315–337). The choice of this discretization strategy is motivated by the fact that this particular set of equations is recasted in a convenient quasi‐conservative form. Cell face values are reconstructed using implicit compact schemes (J. Comput. Phys. 1999; 156:137–180; J. Comput. Phys. 2004; 198:535–566) and time integration is performed with the help of a four‐stage Runge–Kutta method. Numerical properties of the proposed scheme are investigated both, analytically using linear spectral analysis, and numerically for highly nonlinear cases. The numerical analysis indicates that the newly developed scheme has wider stability regions and better spectral resolution than most of the previously published numerical methods used to handle equivalent set of equations. Moreover, it was also noticed that the use of mixed‐order strategies to discretize convective and dispersive terms may result in an important overall reduction of the spectral resolution of the scheme. Additionally, there is some numerical evidence, which seems to indicate that the incorporation of a high‐order dispersion correction term as given by Madsen et al. (Coastal Eng. 1991; 15:371–388) may introduce instability in the system
(International Journal for Numerical Methods in Fluids. vol. 51, n° 0271-2091, pp. 1217-1253, 26/08/2026)
LEGI, UJF, Grenoble INP, CNRS, PUC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Liquefied vs Stratified Sedimentation Mobilization Processes: Insight from the South of the Barbados Accretionary Prism
(Tectonophysics. vol. 428, n° 0040-1951, pp. 33-47, 26/08/2026)
IFP, BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGCA, OSUG, UJF, Grenoble INP, INSU - CNRS, IRSTEA, USMB [Université de Savoie] [Université de Chambéry], CNRS, CNRS, UCP, GEOSCIENCES, PSL
Eco-Cultural Niche Modeling: New Tools for Reconstructing the Geography and Ecology of Past Human Populations
Prehistoric human populations were influenced by climate change and resulting environmental variability and developed a wide variety of cultural mechanisms to deal with these conditions. In an effort to understand the inesfluence of environmental factors on prehistoric social and technical systems, there is a need to establish methods with which to model and evaluate the rules and driving forces behind these human-environment interactions. We describe a new set of analytical tools―an approach termed Eco-Cultural Niche Modeling (ECNM)―that can be used to address these issues and to test current hypotheses. This approach's modeling architectures are used to reconstruct past human systems in the Old and New Worlds, past natural systems within which they operated― namely geological, paleobiological and paleoenvironmental conditions―and also to develop informed hypotheses concerning the geographic spread, migration, and eco-cultural adaptations of prehistoric human populations. The ECNM approach has recently been developed and explored at two National Science Foundation- and European Science Foundation-funded workshops. We describe the goals and methods of ECNM, the results of the proof-of-concept projects, the analytical issues that remain unresolved, and the potential this approach has to offer the disciplines of paleoanthropology and archaeology.
(Paleoanthropology. vol. 2006, n° 1545-0031, pp. 68-83, 26/08/2026)
PACEA, UB, CNRS, KU, KU, ASU, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UCL
Liquefied vs stratified sediment mobilization processes: Insight from the South of the Barbados accretionary prism
This paper discusses the nature and origin of subsurface sediment mobilization processes in deep marine clay-rich environments. In the studied area of the southern Barbados accretionary prism, new geophysical acquisitions have emphasized the spectacular widespread development of mud volcanoes that are well-developed along ramp anticlines and along sigmoidal rises with trends that are oblique to the axes of the main folds of the accretionary wedge. On some active mud volcanoes, heat-flow measurements show high positive anomalies related to high fluxes of mud transfer. The mobilized solid fraction expelled by the mud volcanoes does not originate from a unique source bed but from various formations pierced by the mud conduits and is driven by the water phase. The area studied also exhibits trends of structures corresponding to sub-circular massive local uplifts of deformed but well-preserved stratified sediments (turbidites and hemipelagics). No piercing shale diapirs have been encountered in this area. Some of these local uplift structures are complicated by the development of collapses, calderas, and superimposed mud volcanoes. Mud volcanism corresponds fundamentally to fluid displacement (water and gas), whereas massive sedimentary uplift corresponds to large vertical displacements of stratified solid levels but for which the deep cause could be partly the intrusion of mud plugs. Both are dynamic phenomena controlled by the development of overpressure at depth, contributing to sedimentary mobilizations.
(Tectonophysics. vol. 428, n° 0040-1951, pp. 33–47, 26/08/2026)
IFP, BRGM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LGCA, OSUG, UJF, Grenoble INP, INSU - CNRS, IRSTEA, USMB [Université de Savoie] [Université de Chambéry], CNRS, CNRS, LT, UPMC, INSU - CNRS, UCP, CNRS, GEOSCIENCES, PSL