2007-2008 Schlanger Fellow – Sindia Sosdian

Sindia Sosdian

Rutgers University

The Mid-Pleistocene Transition: Deep Sea Temperature and Global Ice Volume from Mg/Ca and δ18O in Benthic Foraminifera

Abstract

The mid-Pleistocene transition (MPT) (from ~1 to 0.7 Ma), is recorded in benthic foraminiferal oxygen isotope (δ¹⁸O_b) records as a shift in the periodicity of northern hemisphere glaciations from low amplitude 41-kyr to large amplitude 100-kyr glacial-interglacial cycles. The MPT has hypothetically been attributed to 1) global cooling due to a long-term decreasing trend in greenhouse gases; or 2) changes in internal dynamics of ice sheets, independent of changes in atmospheric pCO₂.  Evidence in support of either hypothesis is inconclusive. However. I will construct a high-resolution bottom-water temperature record using Mg/Ca ratios in benthic foraminifera from North Atlantic DSDP Site 607 to quantify the extent of global cooling and, paired with δ¹⁸O_b, estimate the concomitant increase in ice volume.

Biography

I grew up 20 minutes from the New Jersey shore and when I was in high school I learned how to surf. My passion for surfing introduced me to the fundamentals of climate and oceanography. I earned a B.S. degree in chemistry at Monmouth University on the coast of New Jersey, and my combined background in chemistry and surfing motivated me to pursue graduate studies in oceanography. Currently, I am a fifth year Ph.D. student at the Institute of Marine and Coastal Sciences at Rutgers, The State University of New Jersey, in the paleoceanography group with Yair Rosenthal as my advisor. My main research, thus far, involves using geochemical proxies to quantify changes in temperature and ice volume to better understand the causes and mechanisms of Pleistocene glaciations.