Objectif
To determine the environmental and climatic changes which
occurred over intertropical Africa (lat. 8º S; long.
32º 30'E) during the last climatic cycle from lacustrine
sedimentary records, with a high chronological resolution.
Special attention will be focused on short duration changes (10
to 1000 yr).
In East Africa, arid and humid phases have alternated as the
monsoon circulation system has weakened and strengthened. Such
fluctuation can be recorded in lacustrine sediments in response
to varying rainfall and evaporation, which is reflected in lake
level, water chemistry and biota.
Palaeoclimatic investigations will be focused on sites which
offers a continuous sedimentation record. Two mechanical piston
cores (70 to 100m) will be taken in lake Rukwa from sites which
present no hiatuses related to arid phases, erosion processes or
tectonic events. Their location will be based on seismic
profiles. The last 30000 years and especially the arid phases,
such as the last glacial maximum (c.a. 18000 BP) will be
investigated by studying a 20 to 30 m core, to be collected from
a crater lake chosen from among the maars of the Rungwe chain,
South East of L. Rukwa.
Palaeoclimatic proxy data will be formed from biological,
geochemical and mineralogical components. The approach to be
adopted will be quantitative and multidisciplinary, including
structural studies, a seismic survey, sedimentology,
palaeomagnetism, geochemistry, geochronology and
micropalaeontology. To establish calibration with the present
day climatic and environmental parameters, analyses will be made
on surface samples from soils and modern sediments of the lake
and its catchment area. The lacustrine sequence of the last
climatic cycle will be studied using samples representative of
arid and humid phases with special attention on abrupt changes.
The flux of mineral, geochemical, biological, and organic matter
in the lake catchment ecosystem will be calculated and the
erosion intensity fluctuation estimated.
A regional palaeoclimate reconstruction and global modelling will
be developed, in order to understand mechanism of climatic and
hydrological changes that are inferred from proxy data.
Champ scientifique (EuroSciVoc)
CORDIS classe les projets avec EuroSciVoc, une taxonomie multilingue des domaines scientifiques, grâce à un processus semi-automatique basé sur des techniques TLN.
CORDIS classe les projets avec EuroSciVoc, une taxonomie multilingue des domaines scientifiques, grâce à un processus semi-automatique basé sur des techniques TLN.
- sciences naturellessciences de la Terre et sciences connexes de l'environnementgéochimie
- sciences naturellessciences de la Terre et sciences connexes de l'environnementgéologiesédimentologie
- sciences naturellessciences de la Terre et sciences connexes de l'environnementgéologiegéochronologie
- sciences naturellessciences de la Terre et sciences connexes de l'environnementhydrologiebassin hydrologique
- sciences naturellessciences biologiquesécologieécosystème
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Thème(s)
Appel à propositions
Data not availableRégime de financement
CSC - Cost-sharing contractsCoordinateur
13288 Marseille
France