Accession Number : ADP007344

Title :   The Record of Global Change in Circum-Antarctic Marine Sediments,

Corporate Author : NATURAL ENVIRONMENT RESEARCH COUNCIL LONDON (UNITED KINGDOM)

Personal Author(s) : Barker, P. F. ; Pudsey, C. J. ; Larter, R. D.

Report Date : MAR 1992

Pagination or Media Count : 7

Abstract : Sediment drilling, using rigs located on sea ice inshore, and Ocean Drilling Program facilities farther offshore, have described the stepwise cooling of Antarctica through the Cenozoic, setting the scene for more detailed studies of short-period, recent change. Such studies will not be easy. The virtual absence of carbonate sediments and the strength of bottom currents in some regions are fundamental limitations. Nevertheless, Antarctic ocean sediments contain a record of global change which complements the record of the ice sheet, and extends it back in time. Pelagic and hemipelagic sediments of the ocean basins record changes in primary productivity, dissolution, sea ice extent and the strength of deep ocean circulation, and in the volume of the main circum-Antarctic water masses. Prograded sediments of the Antarctic continental shelf and slope contain a record of glacial/interglacial changes in ice sheet volume. Modern piston-coring techniques are capable of revealing changes over the last glacial cycle in some detail, in suitably expanded sections. At lower sediment accumulation rates, a less detailed but longer record can be obtained. It can already be shown that, at and around glacial maximum, (a) grounded ice sheets extended to the Antarctic continental shelf edge, (b) the marginal sea ice zone lay up to 5 deg farther north, and (c) Weddell Sea Bottom Water flow was far slower than at present.

Descriptors :   *OCEAN BOTTOM, *RECORDS, ACCUMULATION, BOTTOM, BOTTOM WATERS, CARBON, CARBONATES, CIRCULATION, COOLING, CYCLES, DEEP OCEANS, DRILLING, FACILITIES, FLOW, GLOBAL, ICE, LIMITATIONS, OCEAN BASINS, OCEAN CURRENTS, OCEANS, OFFSHORE, PISTONS, PRODUCTIVITY, RATES, REGIONS, SEA ICE, SEDIMENTS, SHEETS, SLOPE, TIME, VOLUME, WATER, WATER FLOW, WATER MASSES, SYMPOSIA.

Subject Categories : Geography
      Physical and Dynamic Oceanography
      Snow, Ice and Permafrost

Distribution Statement : APPROVED FOR PUBLIC RELEASE