mirage

Western South Atlantic holocene and glacial deepwater hydrography derived from benthic foraminiferal Cd/Ca and stable carbon isotope data

WHOAS at MBLWHOI Library

a service of the MBLWHOI Library | About WHOAS

Show simple item record

dc.contributor.author Horowitz, Michael
dc.coverage.spatial Western South Atlantic
dc.date.accessioned 2011-07-13T19:57:09Z
dc.date.available 2011-07-13T19:57:09Z
dc.date.issued 1999-01
dc.identifier.uri http://hdl.handle.net/1912/4677
dc.description Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution January 1999 en_US
dc.description.abstract Today, deep waters produced in the North Atlantic are exported through the western South Atlantic. Antarctic intermediate water AAJW also enters the Atlantic in this region. Circumpolar deep water (CDW) fills the depths below AAIW and above and below northern source waters. A depth transect of cores from 1567-3909 m water depth in the western South Atlantic are ideally located to monitor inter-ocean exchange of deep water, and variations in the relative strength of northern versus southern source water production. Last glacial maximum (LGM) Cd/Ca and δ13C data indicate a nutrient-depleted intermediate-depth water mass. In the mid-depth western South Atlantic, a simple conversion of LGM δ13C data suggests significantly less nutrient enrichment than LGM Cd/Ca ratios, but Cd/Ca and δ13C data can be reconciled when plotted in CdW/δ13C space. Paired LGM Cd/Ca and δ13C data from mid-depth cores suggest increasingly nutrient rich waters below 2000 m, but do not require an increase in Southern Ocean water contribution relative to today. Cd/Ca data suggest no glacial-interglacial change in the hydrography of the deepest waters ofthe region. To maintain relatively low Cd/Ca ratios low nutrients in the deepest western South Atlantic waters, and in CDW in general, during the LGM requires an increased supply ofnutrient-depleted glacial North Atlantic intermediate water (GNA1W) and/or nutrient-depleted glacial Subantarctic surface waters to CDW to balance reduced NADW contribution to CDW. LGM Cd/Ca and δ13C data suggest strong GNA1W influence in the western South Atlantic which in turn implies export of GNAIW from the Atlantic, and entrainment of GNA1W into the Antarctic Circumpolar current. en_US
dc.format.mimetype application/pdf
dc.language.iso en_US en_US
dc.publisher Massachusetts Institute of Technology and Woods Hole Oceanographic Institution en_US
dc.relation.ispartofseries WHOI Theses en_US
dc.subject Ocean circulation en_US
dc.subject Oceanic mixing en_US
dc.title Western South Atlantic holocene and glacial deepwater hydrography derived from benthic foraminiferal Cd/Ca and stable carbon isotope data en_US
dc.type Thesis en_US
dc.identifier.doi 10.1575/1912/4677


Files in this item

This item appears in the following Collection(s)

Show simple item record

Search WHOAS


Browse

My Account

Statistics