Orbitally-paced paleoproductivity variations in the Timor Sea and Indonesian Throughflow variability during the last 460-ky
Abstract
A high-resolution ( ∼ 1-2 ky) multi-proxy record from the Timor Sea in the easternmost Indian Ocean (IMAGES Core MD01-2378, Lat. 13 ° 04.95' S, Long. 12 ° 47.27' E, 1783 m water depth) closely tracks changes in intermediate water ventilation and paleoproductivity over the last 460 ky within one of the main outflow passages of the Indonesian Throughflow. Spectral analysis of five different types of flux-based productivity proxies indicates spectral power concentrated in the 100 ky (glacial-interglacial) and 23 ky and 19 ky (precessional) periods. The productivity indicators are coherent and in phase with the precession controlled equatorial winter insolation and generally lead the benthic δ 18O record by 2-3 ky. At terminations, rising sea-level (driven by high latitude forcing) and decreasing NW monsoon (driven by precessional forcing) probably triggered an intensification of the Indonesian Throughflow, stabilizing the upper water column and prohibiting vertical mixing. Thus, productivity fluctuations in the Timor Sea over the last 460 ky were strongly influenced by monsoonal flow patterns in the eastern equatorial Indian Ocean (23 and 19 ky) and were also modulated by the intensity of the Indonesian Throughflow (100 ky).
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2004
- Bibcode:
- 2004AGUFMPP23A1398K
- Keywords:
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- 9330 Australia;
- 4870 Stable isotopes;
- 4267 Paleoceanography;
- 3030 Micropaleontology;
- 1620 Climate dynamics (3309)