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The success of paleoclimatic
and paleooceanographic reconstructions rests on the quality of the
available sedimentary records. A precise understanding of the sedimentology
of the marine or lacustrine zone to be studied is required. The initial
work within the project will start on a group of cores collected
during the past few years in the Atlantic and Mediterranean areas.
Some of them were run in areas critical to the functioning of the
Mediterranean, such as the Gulf of Lion. The sedimentation rate in
said region during the last glacial period was on the order of 0.3
cm/year, thus we will be able to study climate change on scales lower
than decades. To date, no climatic records of such resolution have
been obtained for this region. New cores will be collected as deemed
necessary.
Our paleoceanographic reconstructions will be based on the analysis
of several proxies, whether sedimentary, micropaleontological or
geochemical. In parallel, we will study common proxies and terrestrial
records, such as palynological series, with the objective of establishing
direct correlations with the terrestrial records obtained in the
GRACCIE project. The chronological models of our series will be based
on absolute dating via 14C AMS and isotopic stratigraphy. We will
also consider other methodologies, such as the paleointensity of
magnetic fields that enable direct correlations with terrestrial
records. We will use analytical methodologies such as: stable isotopes
of carbon and oxygen and trace elements in diverse species
of planktonic and benthonic foraminifera, biomarkers, palynology
encompassing parameters such as temperature, volume of polar ice
caps, water salinity, ventilation, nutrients, wind intensity, fluvial
inputs and deep current velocities. Examples of this approach are
given in Martrat et al. (2004, 2009).
Special attention will be devoted to the validation of paleoceanographic
and paleoclimatic reconstructions through the analysis of proxies
in present conditions. We will thus be able to improve calibrations
and consequently increase the precision of climatic reconstructions.
Sediment trap samples from marine and lacustrine environments will
be used for this purpose.
| Martrat, B., Grimalt, J.O., Lopez-Martinez,
C., Cacho, I., Sierro, F.J., Flores, J.A., Zahn, R., Canals,
M., Curtis, J.H. and Hodell, D.A., 2004. Abrupt temperature changes
in the western Mediterranean over the past 250,000 years. Science, 306: 1762-1765. |
Martrat, B., Grimalt, J.O. Shackleton, N.J., de Abreu, L.,
Hutterli, M.A. and Stocker, T.F. 2007. Four climate cycles
of recurring deep and surface water destabilizations on the
Iberian Margin. Science 317, 502-507. |
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