Glacial Mapping:

Observations of the glacial moraines were done by mapping the extent of the various rock types that made up the moraines by a combination of noting where volcanic erratics were found with line counts and area counts. Surface page break exposure dating is to be done using cosmogenic isotopes from large erratics dropped out of the glaciers as they retreated.

Preliminary observations from the extent of volcanic erratics (derived from Ross Island and further south) indicate that the Ross Sea ice mass extended up to ~350 m altitude on Hjorth Hill above Cape Bernacchi, it also covered Marble Pt and Spike Cape. These observations place the limit of Ross Sea ice a minimum of 20 km further north than that previously reported (Hall and Denton, 1994. Antarctic Journal pp 20 - 22).

Moraine deposited by the Ross Sea ice appears to be significantly older, based on weathering and appearance of striations, than moraine deposited by the Wilson Piedmont Glacier. This implies a more recent advance of the Wilson Piedmont which may have overrun earlier Ross Sea moraine.

Future work intends to extend this work further along the coast, which will give an overall picture of the way the coast is rebounding with distance from the Ross Ice Shelf. Studying the beaches on Ross Island, and possibly Beaufort and Franklin Islands will enable a test of the source of the ice causing the isostatic rebound. There may be an isostatic response to expanding local ice on the Victoria Land Coast as well as to grounded ice in the Ross Sea. The beaches on Ross Island have a longer ice free season than elsewhere so will not only provide a comparison on levels of development, but also allow process measurements to be made over a length of time.