This work was supported by US National Science Foundation (NSF) grant OPP-0538120 to Catania and Hulbe.
Journal of Glaciology
Stratigraphic geology -- Antarctica -- Ross Island, Ice sheets -- Antarctica, Geology -- Antarctica, Glaciers -- Antarctica -- Ross Island
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.
Catania, G., C. Hulbe, H. Conway, 2010, Grounding-line basal melt rates determined using radar-derived internal stratigraphy. Journal of Glaciology, 56 (197), 545-554.