HR: 1340h
AN: OS33B-1263 [Abstracts]
TI: A High Resolution Climate Record of the Western Tropical Atlantic During Marine Isotope Stage 5
AU: * Medley, S E
EM: sarahemedley@umail.ucsb.edu
AF: Department of Earth Science and Interdepartmental Graduate Program in Marine Science,
University of California Santa Barbara, Santa Barbara, CA 93106, United States
AU: Lea, D W
EM: lea@geol.ucsb.edu
AF: Department of Earth Science and Interdepartmental Graduate Program in Marine Science,
University of California Santa Barbara, Santa Barbara, CA 93106, United States
AU: Peterson, L C
EM: lpeterson@rsmas.miami.edu
AF: Rosenstiel School of Marine and Atmospheric Science, 4600 Rickenbacker Causeway,
Miami, FL 33149,
AB:
We are constructing a high resolution climate record during the last major interglacial period (MIS 5; 80-130 ky
bp) in the western tropical Atlantic. Mg/Ca sea surface temperature (SST) and δ18Ocalcite
values were determined from analysis of the surface dwelling foraminifer, G. ruber, in piston core MD03-2620
from the anoxic Cariaco Basin on the Northern Venezuelan shelf. A centennial resolution record of
δ18Ocalcite shows millennial scale variability consistent with the NGRIP δ18O
record, including Greenland Interstadial events 19-25. On this timescale in the Cariaco Basin, we've found
temperature excursions of a more gradual nature leading the relatively rapid excursions in oxygen isotopes.
Substage 5e and Termination II are presented in multi-decadal resolution, allowing us to examine centennial
patterns of climate change during the major interglacial period. Termination II shows a large Younger Dryas-like
reversal and we find SSTs during MIS 5e reaching 29°C, approximately 1.5-2°C higher than peak
Holocene values. These temperatures reach western Atlantic warm pool values, suggesting limited upwelling in
the Cariaco Basin and a northward migration of the inter-tropical convergence zone for the duration of this
extreme warm event.
DE: 4802 Anoxic environments (0404, 1803, 4834, 4902)
DE: 4936 Interglacial
DE: 4954 Sea surface temperature
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting