Radionuclide and biomarker proxies of past ocean circulation and productivity in the Arabian Sea

Ali Pourmand, F. Marcantonio, T. S. Bianchi, E. A. Canuel, E. J. Waterson

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We present new excess 231Pa/230Th activity ratios and lipid biomarker results from northeastern Arabian Sea sediments (core 93KL) spanning the past 50 ka in an effort to constrain further the relationship between climate at low and high latitudes. 231Pa/230Th activity ratios are maintained at values significantly higher than the water-column production ratio of 0.093. Average 231Pa/230Th activity ratios are lower during the last glacial period than during the Holocene. The lowest 231Pa/230Th activity ratios coincide with the timing of Heinrich Events 1-5. Profiles of lipid biomarker fluxes and 231Pa/230Th activity ratios from 32 to 12 ka show similar patterns, suggesting that 231Pa is more efficiently scavenged relative to 230Th at times when diatoms make up a proportionally larger part of the primary biomass signal. In the Holocene, high 231Pa/230Th activity ratios may indicate enhanced 231Pa export from the southern to the northern Indian Ocean via intensified thermohaline circulation.

Original languageEnglish (US)
Pages (from-to)1-4
Number of pages4
JournalGeophysical Research Letters
Volume32
Issue number10
DOIs
StatePublished - May 28 2005
Externally publishedYes

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Arabian Sea
biomarkers
productivity
radioactive isotopes
biomarker
radionuclide
oceans
lipid
Holocene
Heinrich event
thermohaline circulation
Last Glacial
sediment core
diatom
water column
lipids
biomass
climate
Indian Ocean
algae

ASJC Scopus subject areas

  • Earth and Planetary Sciences (miscellaneous)

Cite this

Radionuclide and biomarker proxies of past ocean circulation and productivity in the Arabian Sea. / Pourmand, Ali; Marcantonio, F.; Bianchi, T. S.; Canuel, E. A.; Waterson, E. J.

In: Geophysical Research Letters, Vol. 32, No. 10, 28.05.2005, p. 1-4.

Research output: Contribution to journalArticle

Pourmand, Ali ; Marcantonio, F. ; Bianchi, T. S. ; Canuel, E. A. ; Waterson, E. J. / Radionuclide and biomarker proxies of past ocean circulation and productivity in the Arabian Sea. In: Geophysical Research Letters. 2005 ; Vol. 32, No. 10. pp. 1-4.
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