Glacio-isostasy and glacial ice load at Law Dome, Wilkes Land, East Antarctica

Ian D. Goodwin*, Christopher Zweck

*Corresponding author for this work

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

The Holocene sea-level high stand or 'marine limit' in Wilkes Land, East Antarctica, reached ~30 m above present sea level at a few dispersed sites. The most detailed marine limit data have been recorded for the Windmill Islands and Budd Coast at the margin of the Law Dome ice cap, a dome of the East Antarctic Ice Sheet (EAIS). Relative sea-level lowering of 30 m and the associated emergence of the Windmill Islands have occurred since 6900 14C (corr.) yr B.P. Numerical modeling of the Earth's rheology is used to determine the glacio-isostatic component of the observed relative sea-level lowering. Glaciological evidence suggests that most of EAIS thickening occurred around its margin, with expansion onto the continental shelf. Consequently, a regional ice history for the last glacial maximum (LGM) was applied in the glacio-isostatic modeling to test whether the observed relative sea-level lowering was primarily produced by regional ice-sheet changes. The results of the modeling indicate that the postglacial (13,000 to 8000 14C yr B.P) removal of an ice load of between 770 and 1000 m from around the margin of the Law Dome and adjacent EAIS have produced the observed relative sea-level lowering. Such an additional ice load would have been associated with a 40- to 65-km expansion of the Law Dome to near the continental shelf break, together with a few hundred meters of ice thickening on the adjoining coastal slope of the EAIS up to 2000 m elevation. Whereas the observed changes in relative sea level are shown to be strongly influenced by regional ice sheet changes, the glacio-isostatic response at the Windmill Islands results from a combination of regional and, to a lesser extent, Antarctic-wide effects. The correspondence between the Holocene relative sea-level lowering interpreted at the margin of the Law Dome and the lowering interpreted along the remainder of the Wilkes Land and Oates Land coasts (105°-160° E) suggests that a similar ice load of up to 1000 m existed along the EAIS margin between Wilkes Land and Oates Land. (C) 2000 University of Washington.

Original languageEnglish
Pages (from-to)285-293
Number of pages9
JournalQuaternary Research
Volume53
Issue number3
DOIs
Publication statusPublished - May 2000
Externally publishedYes

Keywords

  • East Antarctica
  • Glacio-isostacy
  • Holocene
  • Ice sheet
  • Sea level
  • Wilkes Land

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