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Detailed Reference Information |
Stott, L.D. and Tang, C.M. (1996). Reassessment of foraminiferal-based tropical sea surface d18O paleotemperatures. Paleoceanography 11: doi: 10.1029/95PA03344. issn: 0883-8305. |
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The possibility exists that the magnitude of Glacial/Holocene Δ18O change in the tropical oceans was previously under-estimated due to the dampening effect of bioturbation on bulk foraminiferal Δ18O measurements. We have investigated this possibility by isotopically analyzing suites of individual planktonic foraminifera from box core samples from the equatorial Atlantic. We present oxygen isotopic results for individual specimens of two surface-dwelling planktonic foraminiferal Globigerinoides ruber (white) and Globigerinoides sacculifer (no final sac) from glacial-age box core samples from seven sites located between about 15¿N and 15¿S in the tropical Atlantic. These data are used to contrain the minimum glacial temperatures recorded by tropical surface-dwelling planktonic foraminifera during the last glacial maximum. The individual foraminiferal Δ18O temperatures reveal minimum sea surface temperatures (SSTs) that ranged from 1 ¿C colder to as much as 5¿ to 6 ¿C colder than present-day summer SSTs after correcting for an ''ice volume effect.'' However, these minimum temperatures represent less than 10% of the foraminiferal population measured from glacial horizons. Approximately 80% of the glacial specimens record temperatures that were within 2¿C of the mean Holocene SST. We conclude that either the tropical Atlantic was not pervasively colder during the Glacial or that there was a systematic negative shift in the isotopic composition of the surface waters that offset a more significnat temperature change. ¿ American Geophysical Union 1996 |
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Abstract |
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Keywords
Oceanography, General, Paleoceanography |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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