- journal_title：Geology
- Contributor：J.A. Dowdeswell ; D. Ottesen ; J. Evans ; C. Ó Cofaigh ; J.B. Anderson
- Publisher：Geological Society of America
- Date：2008-
- Format：text/html
- Language：en
- Identifier：10.1130/G24808A.1
- journal_abbrev：Geology
- issn：0091-7613
- volume：36
- issue：10
- firstpage：819
The rate of deglacial ice-sheet retreat across polar continental shelves, and possible ice-stream collapse and sea-level rise, has been much debated. High-resolution imagery of seafloor morphology is available for many polar shelves and fjords. The rapidity of ice retreat is inferred from diagnostic assemblages of submarine landforms, produced at ice-stream sedimentary beds. These landforms, exposed by ice retreat across high-latitude shelves, demonstrate that deglaciation occurs in three main ways: rapidly, by flotation and breakup; episodically, by still-stands and/or grounding events punctuating rapid retreat; or by slower retreat of grounded ice. Submarine landform assemblages imply, through the presence of grounding-zone wedges overprinting mega-scale glacial lineations on many polar shelves, that ice-stream retreat is more often episodic than catastrophic. These observations provide a robust test of the ability of numerical models to predict the varied response of ice-sheet basins to environmental changes.