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(Article of periodic en Anglais - 1981)

Document title

The mode and mechanism of the last deglaciation: oceanic evidence

Authors(s) and Affiliation(s)

RUDDIMAN W. F. ; McINTYRE A. ;

Abstract

Changes in ocean temperature, carbonate productivity, and ice-rafted detritus in the North Atlantic suggest that half of the Northern Hemisphere ice volume at the last glacial maximum had disappeared by 13,000 yr B.P., despite the still-extensive limits of the ice sheets. This early thinning of the ice sheets occurred during a time when summer insolation values were slowly rising but when pollen evidence south of the ice margins indicates cold, dry air masses. We infer that this rapid early ice disintegration (16,000 13,000yr B.P.) was caused by oceanic mechanisms: (1) rising sea level, causing increased calving along ice margins: (2) the chilling of the sea-surface by iceberg and melwater, reducing moisture extraction by the atmosphere and transport to the ice sheets| and (3) winter freezing of the low-salinity meltwater layer, supressing local moisture extraction and the regional influx of moisture-bearing storms from lower latitudes in winter and hence starving the ice sheets. These oceanic feedback mechanisms were strongest from 16,000 to 13,000yr B.P., and weaker but still active from that date until the end of deglaciation at 6000yr B.P.

Source

Article of periodic

published at : Quaternary research New York

Editor :

Millesime : 1981, vol. 16, no2 [pp. 125-134]

Bibliographic references : 48 réf.

Language

Anglais

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