Published In

Journal of Glaciology

Document Type

Article

Publication Date

1-1-2010

Subjects

Stratigraphic geology -- Antarctica -- Ross Island, Ice sheets -- Antarctica, Geology -- Antarctica, Glaciers -- Antarctica -- Ross Island

Abstract

We use ice-penetrating radar data across grounding lines of Siple Dome and Roosevelt Island, Antarctica, to measure the spatial pattern, magnitude and duration of sub-ice-shelf melting at these locations. Stratigraphic layers across the grounding line show, in places, a large-amplitude downwarp at, or slightly downstream of, the grounding line due to sub-ice-shelf basal melting. Localized downwarping indicates that melting is transient; melt rates, or the grounding line position, have changed within a few hundred years in order to produce the observed stratigraphy. Elsewhere, no meltrelated stratigraphic signature is preserved. In part, heterogeneity in the amount of sub-ice-shelf melt is due to regional circulation patterns in the sub-shelf cavity, but local (on the order of tens of kilometers) heterogeneity in the melt pattern may reflect small differences in the shape of the ice-shelf base at the grounding line. We find that all of the grounding lines crossed have been in place for at most ~400 years.

Description

Originally appeared in Journal of Glaciology, published by the International Glaciological Society. Article can be found at http://www.igsoc.org/journal/

DOI

10.3189/002214310792447842

Persistent Identifier

http://archives.pdx.edu/ds/psu/8429

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