Hydrological Cycle in the Indonesian Archipelago and Rapid Climate Changes During Glacial Period at low Latitudes
Abstract
An high resolution (0.2-0.6 ka) record of paired measurements of Mg/Ca and δ18Oc (calcite) were obtained on planktonic foraminifera Globigerinoides ruber (white) picked from core MD98-2165 (east tropical Indian Ocean ; 9°38'S, 118°20'E) over the 0-200 ka time interval (extending back in time PhD thesis's work of C. Levi on the LGM-Holocene transition). Cleaning procedure for Mg/Ca followed Barker et al., 2003's procedure and Mg/Ca ratios were performed at the LSCE on an ICP-OES following de Villiers et al, 2002's method. Mg/Ca precisions obtained on G. ruber samples are 4.2% (1σ, pooled RSD). Using the Mg/Ca-SST estimates and coupled δ18Oc measurements, a record of water δ18O has been calculated; corrected for ice-volume global contribution using Waelbroeck et al., 2002 reconstruction. Our results suggest a narrow climatic coupling between low latitudes hydrological cycle and northern high latitude climate during the last glacial period, with a reconstructed surface water saltier (around 0.5 psu) and slightly warmer (0.2-1°C) associated with North Atlantic cold episodes. This coupling is in agreement with a weakening of the East Asian monsoon activity during cooling of the Europe-Asia continent that can be explained by a southward shift of the ITCZ as proposed by Labeyrie et al. (C.R. Geosciences, 2004).
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFMPP31B1742C
- Keywords:
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- 1605 Abrupt/rapid climate change (4901;
- 8408);
- 1635 Oceans (1616;
- 3305;
- 4215;
- 4513);
- 1637 Regional climate change;
- 3030 Micropaleontology (0459;
- 4944);
- 4901 Abrupt/rapid climate change (1605)