Dissertation/Thesis Abstract

Millennial-scale Variability to 735 ka: High-resolution Climate Records from Santa Barbara Basin, CA
by White, Sarah Marie, M.S., University of California, Davis, 2012, 238; 1530014
Abstract (Summary)

Determining the ultimate cause and effect of millennial-scale climate variability remains an outstanding problem in paleoclimatology, partly due to the lack of high- resolution records extending beyond the last glacial period. New cores from Santa Barbara Basin provide ∼5000 year "windows" of climate with ∼50-year resolution dating to ∼293 ka (the MIS 8.6-8.5 transition), ∼460 ka (MIS 12), and ∼735 ka (MIS 18). These records span the Late Pleistocene, during which the 100-kyr cycle gained power in global climate records and the magnitude of glacial-interglacial cyclicity increased. Thus, these records provide a test of the dependence of millennial-scale behavior on variations in glacial-interglacial cyclicity. Planktonic foraminiferal δ 18O indicates that millennial-scale variability is present in all three intervals, and is similar to that during MIS 3. Stadial G. bulloides δ18O values were 2.75-1.75 ‰ (mean 2.25 ‰) and interstadial values were 1.75-0.5 ‰ (mean 1 ‰), with rapid interstadial initiations of 1-2 ‰, as in MIS 3. Interstadials were ∼300-1300 years long and spaced ∼750-1500 years apart, consistent with MIS 3 interstadial durations. Upwelling increased during interstadials, but did not vary synchronously with surface water temperatures, again similar to MIS 3. These high-resolution records provide evidence that millennial-scale variability was an inherent feature of glacial climates in the Northern Hemisphere throughout the past 735 ka.

Indexing (document details)
Advisor: Hill, Tessa M.
Commitee: Montanez, Isabel P., Spero, Howard J.
School: University of California, Davis
Department: Geology
School Location: United States -- California
Source: MAI 51/03M(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Paleoclimate Science, Geochemistry
Keywords: Abrupt, Carbon, Isotope, Micropaleontology, Oxygen, Paleoceanography
Publication Number: 1530014
ISBN: 9781267760302