HR: 0800h
AN: U31A-0005    [Abstracts]
TI: Northern-Southern Hemisphere Comparison of Aeolian Dust Records Over the Last 800 Kyr.
AU: * Petit, J
EM: petit@lgge.obs.ujf-grenoble.fr
AF: LGGE-CNRS, BP96, St Martin d Heres, 38402 France
AU: Delmonte, B
AF: LGGE-CNRS, BP96, St Martin d Heres, 38402 France
AU: Delmonte, B
AF: University Milano Bicocca, Piazza della Scienze, Milano, 20126
AU: Lambert, F
AF: University of Bern, Sidlerstrasse 5, Bern, 3112 Switzerland
AU: Ruth, U
AF: Alfred Wegener Institute, Columbusstraáe, Bremmerhaven, 27568 Germany
AU: Bigler, M
AF: University of Bern, Sidlerstrasse 5, Bern, 3112 Switzerland
AU: Maggi, V
AF: University Milano Bicocca, Piazza della Scienze, Milano, 20126
AU: Steffensen, J
AF: Department of Geophysics, Juliane Maries Vej 30, Copenhagen, 2100 Denmark
AB: The 3130m-deep ice core from Dome C obtained in the frame of the European Project of Ice Coring in Antarctica (EPICA) depicts 8 glacial periods. Here we present the results of dust content and we extend the record down to 3200 m, corresponding to circa 800 kyr B.P. The dust has been measured by using two independent techniques: a laser system deployed on the field and used for continuous measurements and counting in laboratory by using Coulter Counter (Multisizer II) on discrete samples from about 1200 levels. The laser and Coulter EPICA dust profiles are well consistent. Amongst Antarctic records, over the last 4 climate cycles, the EPICA-Dome C dust record mimics the Vostok one and several dust events could be confidently used as stratigraphic markers since the records share the same dust sources. The high dust input (up to a factor 50 with respect to present time) characterising the high latitude records during glacial climate is linked to the synergetic effect of several factors, among which the extension of ice caps and periglacial areas, the bigger continental aridity and reduced hydrologic cycle, as well as the change in the atmospheric circulation. At the first order, the dust concentration could be linked to glacial conditions and therefore to the global ice volume. The EPICA dust record is extended to MIS 20. The record shares several common pattern with the global ice volume, and also with the Northern Hemisphere dust records from the Chinese loess and with marine records from western Pacific ocean. Among patterns, the glacial stages MIS 14 and MIS 16 appear less and well defined respectively while the interglacial period MIS 13 and MIS 15 are not well marked on all records. For prior periods, EPICA record displays better resolution and marked glacial MIS 18 and 20 stages. Interestingly, the long term progressive increasing glaciation depicted from western Pacific record likely associated to the Himalayan uplift, is also suggested from the EPICA dust record.
DE: 3344 Paleoclimatology
DE: 4267 Paleoceanography
DE: 1600 GLOBAL CHANGE (New category)
SC: Union [U]
MN: 2004 AGU Fall Meeting