A5080523296- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Marine and coastal ecosystems
- Geological and Geophysical Studies
- Isotope Analysis in Ecology
- Paleontology and Stratigraphy of Fossils
- Marine Biology and Ecology Research
- Hydrocarbon exploration and reservoir analysis
- Geological formations and processes
- Geological Studies and Exploration
- Ocean Acidification Effects and Responses
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Oceanographic and Atmospheric Processes
- Geomagnetism and Paleomagnetism Studies
- Planetary Science and Exploration
- Marine and environmental studies
- Offshore Engineering and Technologies
- Geochemistry and Geologic Mapping
- Drilling and Well Engineering
- Spacecraft and Cryogenic Technologies
- Pacific and Southeast Asian Studies
- Astronomical Observations and Instrumentation
- Reservoir Engineering and Simulation Methods
- Geological Modeling and Analysis
Institut de Recherche pour le Développement
2011-2025
Centre National de la Recherche Scientifique
2015-2025
Aix-Marseille Université
2015-2025
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2020-2025
Centre de Recherche et d’Enseignement de Géosciences de l’Environnement
2016-2025
Sustainable Europe Research Institute
2005-2021
Collège de France
2004-2021
Laboratoire Méditerranéen de Préhistoire Europe Afrique
2003-2020
Centre de Gestion Scientifique
2014
Beicip Franlab (France)
2003-2006
Abstract Marine phytoplankton play important roles in the global ecosystem, with a limited number of cosmopolitan keystone species driving their biomass. Recent studies have revealed that many these are complexes composed sibling species, but little is known about evolutionary processes underlying formation. Gephyrocapsa huxleyi, widely distributed and abundant unicellular marine planktonic algae, produces calcified scales (coccoliths), thereby significantly affects biogeochemical cycles via...
Analysis of a continuous sedimentary record taken in the Maldives indicates that strong primary production fluctuations (70 to 390 grams carbon per square meter year) have occurred equatorial Indian Ocean during past 910,000 years. The is coherent and phase with February insolation, whereas it shows diverse behavior δ 18 O, depending on orbital frequency (eccentricity, obliquity, or precession) examined. These observations imply direct control productivity oceanic system by insolation. In...
Late Pleistocene changes in oceanic primary productivity along the equator Indian and Pacific oceans are revealed by quantitative nanoplankton communities preserved nine deep-sea cores. We show that variations equatorial primarily caused glacial-interglacial variability precession-controlled east-west thermocline slope of Indo-Pacific. The linked to processes similar Southern Oscillation phenomenon, they precede oxygen isotopic ratio, which indicates not result ice sheet fluctuations....
We studied the direct effects of CO2 and related changes in seawater carbonate chemistry on marine planktonic organisms a mesocosm experiment. In nine outdoor enclosures (~11 m3 each), partial pressure (pCO2) was modified by an aeration system. The triplicate treatments represented low (~190 parts per million volume (ppmV) CO2), present (~410 ppmV high (~710 CO2) pCO2 conditions. After initial fertilization with nitrate phosphate bloom dominated coccolithophorid Emiliania huxleyi occurred...
Coccolithophores are one of the most abundant eukaryotic phytoplankton in oceans and distinguished by their ability to build calcitic platelets (coccoliths). Of numerous species, Emiliania huxleyi is considered major calcifiers pelagic ocean. There growing concern that increasing levels CO2 atmosphere subsequent acidification ocean may disrupt production coccoliths. Furthermore, any change global distribution abundance E. relative non-calcifying groups (e.g. diatoms) will have important...
Since Last Glacial Maximum (23–19 ka), Earth climate warming and deglaciation occurred in two major steps (Bølling‐Allerød Preboreal), interrupted by a short cooling interval referred to as the Younger Dryas (12.5–11.5 ka B.P.). In this study, three cores (MV‐33, MV‐66, MD‐40) collected central part of Pandora Trough (Gulf Papua) have been analyzed, they reveal detailed sedimentary pattern at millennial timescale. Siliciclastic turbidites disappeared during Bølling‐Allerød Preboreal...
Appendix Table Al Is available with entire article onmicrofiche. Order from the American Geophysical Union, 2000Florida Avenue, N.W., Washington, D.C. 20009. DocumentP94‐001; $2.50. Payment must accompany order. We examined coarse fraction contents of pelagic carbonates deposited between 2000‐and 3700‐m water depth in tropical Indian Ocean using Drilling Program (ODP) sites 722 (Owen Ridge, Arabian Sea) and 758 (Ninetyeast eastern equatorial Ocean), four giant piston cores collected by...
High‐resolution micropaleontological (planktonic foraminifera and calcareous nannofossils) geochemical (stable isotopes, organic carbon, Fe, P, S, Ca, Ba, Mn, Al) records are presented for the first sapropel‐containing carbonate cycle in Pliocene of Sicily. The is characterized by a gray to white beige color layering typical marls Trubi formation. A faintly laminated sapropel intercalated gray‐colored bed cycle. CaCO 3 content varies from 40% 45‐50% layers. Lowest 25–30% found layer...
Research Article| October 01, 2005 Weight estimates of coccoliths using the optical properties (birefringence) calcite Luc Beaufort CNRS-Université Aix-Marseille III, CEREGE, Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence Cedex 04, France email: beaufort@cerege.fr Search for other works by this author on: GSW Google Scholar Micropaleontology (2005) 51 (4): 289–297. https://doi.org/10.2113/gsmicropal.51.4.289 Article history first online: 09 Mar 2017 Cite View This Citation Add to Manager...
Sea surface temperature (SST) and salinity of the Western Pacific Warm Pool (WPWP) reflect global climate effects such as El Niño–Southern Oscillation phenomenon. However, reconstructions past changes in WPWP from geologic record vary depending on specific proxy used. Here we develop a multiproxy last deglaciation radiocarbon‐dated sediment core (MD97‐2138) retrieved heart WPWP. SST for 30,000 years based planktonic foraminiferal Mg/Ca ( Globigerinoides ruber sacculifer ), alkenone...
Abstract. BIOSOPE cruise covered an oceanographic transect through the centre of South Pacific Gyre (SPG) from Marquesas archipelago to Peru-Chile upwelling (PCU). Water samples 6 depths in euphotic zone were collected at 20 stations. The concentrations suspended calcite particles, coccolithophores cells and detached coccoliths estimated together with size weight using automatic polarizing microscope, a digital camera, collection softwares performing morphometry pattern recognition. Some...
Abstract Geomagnetic dipole moment variations associated with polarity reversals and excursions are expressed by large changes of the cosmogenic nuclide beryllium‐10 ( 10 Be) production rates. Authigenic Be/ 9 Be ratios (proxy atmospheric production) from oceanic cores therefore complete classical information derived relative paleointensity (RPI) records. This study presents new authigenic ratio results obtained MD05‐2920 MD05‐2930 collected in west equatorial Pacific Ocean. MD05‐2920,...