Document Type
Thesis
Abstract
Signals from abrupt, but significant Heinrich (H) and Dansgaard-Oeschger (DO) climatic events are evident in ostracode assemblages from the Central Arctic Ocean for the last ~50ka. These assemblages identify four distinct zones, or periods of time with distinctly different paleoceanographic conditions, which are interpreted as changing sources of Arctic Ocean Deep Water (AODW) caused by these abrupt climate changes. These changes indicate stadial conditions from ~50-46ka with AODW source-water originating from brine formation at the Arctic Ocean surface. This is what we expect to see during typical "glacial" conditions (Haley et al., 2007). However, from ~45-18ka, the AODW source-water came primarily from North Atlantic inflow, which is more indicative of warmer conditions (Haley et al., 2007). This is likely due to the high frequency of warm DO events, especially during the first half of this time period. Following this surprisingly warm signal, from ~ 18-9ka there is an initial cooling signal from an increase in the influence of brine formation to the AODW. However, we then see a signal that is more expected during Termination 1 into the early Holocene, continued North Atlantic inflow continued. The final zone from ~9-0ka shows a distinct cooling signal from the Holocene, identifying the pre-anthropogenic conditions in the Central Arctic Ocean.
Date Awarded
2011
Department
Geology
Advisor 1
Rowan Lockwood
Recommended Citation
Poirier, Robert K., "Late Quaternary Ostracode Assemblages from the Central Artic Ocean: A Paleoclimate/Paleoceanographic Reconstruction for the Last 50ka" (2011). Geology Senior Theses. William & Mary. Paper 259.
https://scholarworks.wm.edu/geologyseniors/259
