DID CHANGES IN ANTARCTIC ICE VOLUME INFLUENCE LATE HOLOCENE SEA-LEVELLOWERING

There has been great debate over the last few decades on the magnitude and causes of relative sea-level lowering during the late Holocene. T he principal attributed causes are geodynamic rather than glacio-eusta tic. An alternative partial cause is an increase in Antarctic ice volu me. Glaciological and glacial geological held evidence indicates that during the late Holocene, the Antarctic alpine glaciers, ice sheet mar gins and outlet glaciers have expanded, and the ice sheet interior has thickened. This is attributed to: (i) an ice thickening in central Ea st Antarctica throughout the Holocene, which was caused by the 50% hig her Holocene snow accumulation rates than those during the glacial sta ge, coupled with the slow reaction time for ice sheet velocities to re spond to the increased accumulation and temperature; and (ii) increase d ice volume supplied by higher than mean Holocene accumulation rates, associated with a warmer climatic period between 4000 to 2500 years B .P. It is estimated that these effects could account for similar to 1. 0 +/- 0.2 m of the interpreted sea-level lowering on mid-oceanic islan ds, with similar to 0.7 +/- 0.1 m of lowering occurring between 4000 a nd 2500 years B.P. (C) 1998 Elsevier Science Ltd. All rights reserved.