Variations of the Antarctic Circumpolar Current intensity during the past 500 ka

Type Article
Date 2010-08
Language English
Author(s) Mazaud A.1, Michel Elisabeth1, Dewilde F.1, Turon J. L.2
Affiliation(s) 1 : UVSQ, CNRS, CEA, Domaine CNRS,Lab Sci Climat & Environm, F-91198 Gif Sur Yvette, France.
2 : Univ Bordeaux 1, UMR 5805, F-33405 Talence, France.
Source Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2010-08 , Vol. 11 , N. 8 / Q08007 , P. 1-10
DOI 10.1029/2010GC003033
WOS© Times Cited 24
Keyword(s) Antarctic, current, past, cycles
Abstract We examine the past variations of the Antarctic Circumpolar Current (ACC) by using variations in size and abundance of the magnetic grains deposited by this current at a site east the Kerguelen-Crozet plateau. Core MD00-2375G was taken at a midlatitude site during the ANTAUS cruise conducted in 2000 by the French R/V Marion Dufresne. Marine isotope stages (MIS) down to MIS 13 are identified, and an age model is derived from a correlation to the ice core isotopic record obtained from EPICA in Antarctica. Continuous records of abundance and size of the magnetic grains were obtained using environmental magnetism methods. Results show a strong modulation of the ACC flow intensity in response to glacial and interglacial cycles. The low abundance and the small size of magnetic grains indicate that the ACC was weak during warm stages and strong during glacial epochs. A large modulation is also observed at the sub-stage scale during the interglacials. A minimum in concentration and grain size occurs at the onset of MIS 11. At the MIS 6-5, 10-9, and possibly 12-11 transitions, observed variations suggest a mechanism involving both rapid and progressive variations of the ACC flow at deglaciations.
Full Text
File Pages Size Access
Publisher's official version 10 964 KB Open access
Top of the page