Quantifying Changes in Thermohaline Circulation Rates During the Last 30 ka Using Radionuclides in Atlantic Sediments

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

The goal of this study is to evaluate whether 231Pa/230Th can be used as a nutrient-independent measure of the vigor of thermohaline circulation in the ocean. 231Pa has a residence time similar to the time scale of NADW (N. Atl. Deep Water), whereas 230Th has a much shorter residence time. Because of this, 231 Pa is exported from the Atlantic into CPDW; the 231Pa/230Th of sediments in the Atlantic reflect the extent of export and thus the vigor of THC. The ratio will be measured in sediments from 12 areas of the Atlantic with ICPMS to look at changes in the THC from Holocene and glacial times. The data will be used to constrain circulation models.