Aeolian dust in East Antarctica (EPICA-Dome C and Vostok): Provenance during glacial ages over the last 800 kyr

Barbara Delmonte (1) , P. S. Andersson (2) , Margareta Hansson (3) , H. Schöberg (2) , Jean-Robert Petit (4) , Isabelle Basile-Doelsch (5) , V. Maggi (1)

1 DISAT - Dipartimento di Scienze dell'Ambiente e del Territorio
2 Laboratory for Isotope Geology
3 Department of Physical Geography and Quaternary Geology
4 LGGE - Laboratoire de glaciologie et géophysique de l'environnement
5 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement

Aeolian mineral dust archived in Antarctic ice cores represents a key proxy for Quaternary climate evolution. The longest and most detailed dust and climate sequences from polar ice are provided today by the Vostok and by the EPICA-Dome C (EDC) ice cores. Here we investigate the geographic provenance of dust windborne to East Antarctica during Early and Middle Pleistocene glacial ages using strontium and neodymium isotopes as tracers. The isotopic signature of Antarctic dust points towards a dominant South American origin during Marine Isotopic Stage (MIS) 8, 10, 12, and back to MIS 16 and 20 as deduced from EDC core. Data provide evidence for a persistent overall westerly circulation pattern allowing efficient transfer of dust from South America to the interior of Antarctica over the last 800 kyr. Some small but significant dissimilarity between old and recent glacial ages suggests a slightly reduced Patagonian contribution during ancient glaciations.

Mots clés: Antarctica; dust; Sr Nd isotopes

Domaines: Glaciologie

Barbara Delmonte, P. S. Andersson, Margareta Hansson, H. Schöberg, Jean-Robert Petit, et al.. Aeolian dust in East Antarctica (EPICA-Dome C and Vostok): Provenance during glacial ages over the last 800 kyr. Geophysical Research Letters, 2008, 35 (L07703), 1 à 6 p. ⟨10.1029/2008GL033382⟩. ⟨insu-00378332⟩