Variations of the ACC-CDW during MIS3 traced by magnetic grain deposition in midlatitude South Indian Ocean cores: Connections with the northern hemisphere and with central Antarctica

We examine the magnetic mineral deposition in three cores located at midlatitude sites in the South Indian Ocean, in an area where sediment eroded from the Kerguelen-Crozet plateau and transported by the marine currents, principally the Antarctic Circum Current, accumulates at a high sedimentation r...

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Bibliographic Details
Published in:Geochemistry, Geophysics, Geosystems
Main Authors: Mazaud, A., Kissel, C., Laj, C., Sicre, M. A., Michel, E., Turon, J. L.
Format: Article in Journal/Newspaper
Language:English
Published: Amer Geophysical Union 2007
Subjects:
paleoceanography
south
Indian
ocean
paleoclimatology and paleoceanography
environmental magnetism
interhemispheric phasing
Antarctic
Byrd
Greenland
Kerguelen
The Antarctic
Antarc*
Antarctica
North Atlantic Deep Water
North Atlantic
Online Access:https://archimer.ifremer.fr/doc/00235/34612/32954.pdf
https://doi.org/10.1029/2006GC001532
https://archimer.ifremer.fr/doc/00235/34612/
Description
Summary:We examine the magnetic mineral deposition in three cores located at midlatitude sites in the South Indian Ocean, in an area where sediment eroded from the Kerguelen-Crozet plateau and transported by the marine currents, principally the Antarctic Circum Current, accumulates at a high sedimentation rate. We focus on Marine Isotopic Stage 3, characterized by large climatic fluctuations at northern latitudes, and compare the obtained records to the climatic records at Byrd ( Antarctica) and Summit (GISP2, Greenland) and to the North Atlantic Deep Water variations in the North Atlantic. Magnetic mineral deposition at the studied sites exhibits a profile with maxima at the time of Heinrich events H4 and H5, which suggests a strong Antarctic Circum Current when the North Atlantic Deep Water was reduced at northern latitude during these events. We show that an interhemispheric seesaw, characterized by temporary surface warmings in the southern hemisphere, is also marked by a strong Antarctic Circum Current at the time of the northern Heinrich events. The rapid Dansgaard-Oeschger oscillations evidenced in the northern records after interstadials IS12 and IS8 are not visible, suggesting a limited counterpart of these events in the midlatitude southern Indian Ocean.

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