Holocene Variations in Upper North Atlantic Deep Water(Labrador Sea Water) Properties

Columbia University, New York NY

Investigators

Abstract

Summary: The project will reconstruct Holocene millennial-scale changes in upper NADW properties in three cores on the Laurentian Slope that form a transect between 1035 and 1854m water depth. Oxygen isotope, Mg/Ca, Cd/Ca and Zn/Ca measurements will be done on benthic foraminifers to characterize deep water properties including temperature and salinity estimates. Chronology will be constrained by AMS 14C dates. Preliminary data indicate the cores have accumulation rates of 20-50cm/kyr. Sampling intervals will range from 40-60 years. Oxygen isotope and Mg/Ca measurements of the planktic foraminifer G. bulloides in the Holocene section of a core near the mouth of the Labrador sea to relate the deep water changes to surface water changes.