The first moderate to high-resolution Holocene marine stable isotope record from the near-shore Antarctic continental shelf (ODP Hole 1098B) suggests sensitivity of the western Antarctic Peninsula hydrography to westerly wind strength and ENSO-like climate variability. Despite its proximity to corrosive Antarctic water masses, sufficient CaCO (sub 3) in Palmer Deep sediments exists to provide a high-quality stable isotopic record (especially in late Holocene). Coherence of benthic foraminifer delta (super 18) O, delta (super 13) C, sedimentologic, and CaCO (sub 3) fluctuations suggests that rapid (>20 yr) Palmer Deep bottom water temperature fluctuations of 1-1.5 degrees C are associated with competitive interactions between two dominant oceanographic/climatic states. An abrupt shift from a warmer, stable Upper Circumpolar Deep Water (UCDW) state to a cooler, variable Shelf Water state occurred at approximately 3.6 ka. Palmer Deep bottom waters oscillated between UCDW and shelf water-dominated states between approximately 3.6 and 0.05 ka. Cool shelf water intervals correlate with Neoglacial events; the most recent and largest being the Little Ice Age (LIA; approximately 0.7-0.2 ka). Similarities between Palmer Deep and global Holocene records and the rapidity of inferred bottom water fluctuations suggest that western Antarctic Peninsula shelf hydrography has not been controlled by thermohaline reorganizations, but by variable strength and/or position of the Southern Hemisphere westerly wind field. We suggest that these atmospheric perturbations may have originated in the low latitude tropical Pacific.

West: -64.1228 East: -64.1228 North: -64.5143 South: -64.5143

Expedition: 178

Site: 178-1098

Provider: SEDIS Publication Catalogue

Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=2006-000818 (c.f. for more detailed metadata)

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