HR: 17:00h
AN: PP34B-05 INVITED     [Abstracts]
TI: The Atlantic-Pacific Salinity Contrast and Sea Level During Marine Isotope Stage 11
AU: * McManus, J F
EM: jmcmanus@whoi.edu
AF: Woods Hole Oceanographic Institution, Dept of Geology and Geophysics, Woods Hole, MA 02543 United States
AU: Oppo, D W
EM: doppo@whoi.edu
AF: Woods Hole Oceanographic Institution, Dept of Geology and Geophysics, Woods Hole, MA 02543 United States
AU: Cullen, J L
EM: jcullen@whoi.edu
AF: Salem State College, Dept. of Geol., Salem, MA 01970 United States
AU: Huybers, P
EM: phuybers@whoi.edu
AF: Woods Hole Oceanographic Institution, Dept of Geology and Geophysics, Woods Hole, MA 02543 United States
AB: Several lines of evidence suggest that sea level may have been more than 20 meters higher during Marine Isotope Stage 11 (MIS 11) than during the Holocene. Yet high-resolution oxygen isotope records from the Atlantic for these two time periods display negligible differences. One way to reconcile these apparently conflicting observations would be a greater salinity contrast between the Atlantic and Pacific oceans. This contrast is maintained today by asymmetric atmospheric water vapor transport and by differing salinities in the northern and southern deep waters that combine to fill the deep Pacific. In order to test whether the salinity difference was greater during MIS 11 than the today, we compare isotope records from sites in the Atlantic and Pacific. These sites include ODP Sites 980 (55°N, 15°W, 2.2km) and 983 (60°N, 24°W, 2.0km) in the North Atlantic, ODP Site 925 (4°N, 43°W, 3.0km) in the tropical Atlantic, ODP Site 1238 (2°S, 82°W, 2.4km) in the eastern tropical Pacific, and ODP Site 806 (0°N, 159°W, 2.5km) in the western tropical Pacific. The benthic oxygen isotope records from the Atlantic display no measurable difference between MIS 11 and Holocene, while the Pacific records are more variable, but suggest that MIS 11 values are lower by approximately 0.1 per mil. The results are not easily consistent with a 20-meter higher sea level during MIS 11, but they do allow a smaller rise combined with a greater salinity contrast between oceans.
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 1050 Marine geochemistry (4835, 4845, 4850)
DE: 1051 Sedimentary geochemistry
DE: 3344 Paleoclimatology (0473, 4900)
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005