Abrupt climate variability during the last glacial and the late Holocene from the western tropical Pacific perspective ...

• Main Author: Saikku, Reetta Maaria author
• Format: Thesis
• Language: English
• Published: University of Southern California Digital Library (USC.DL) 2009
• Subjects: Geological Sciences degree program; Doctor of Philosophy degree; College of Letters, Arts and Sciences school; Greenland; Pacific; ice core
• Online Access: https://dx.doi.org/10.25549/usctheses-m1997; https://digitallibrary.usc.edu/asset-management/2A3BF1GOWNCI

In Project I, Western tropical Pacific sea surface temperatures and Pacific Deep Water temperatures during Marine Isotope Stage 3 have been reconstructed from the ?18O and Mg/Ca of planktonic and benthic foraminifera from Marion Dufresne core MD98-2181. This 36m marine core was collected at 6.3�N from a water depth of 2114m. With sediment accumulation rates of up to 80cm/ky, it provides a decadally-resolved history of ocean variability during the last glacial period. Surface temperatures and salinities at this site varied in close association with millennial-scale atmospheric temperature swings at high northern latitudes as reflected in the GISP2 ice core. At times of colder atmospheric temperatures over Greenland, the western Pacific was more saline and summer season SSTs were ~2oC colder. These millennial scale changes within the tropics are attributed to a southward displacement of the summer season ITCZ in response to steeper meridional temperature gradients within the Pacific. The benthic ?18O record ...