Routes and Sea Ice:

K042 followed bulldozed roads on the sea ice between Scott Base, Butter Pt and Marble Pt. We followed the surveyors inshore tracks between Marble Pt and Dunlop Island; deviating offshore to check sea ice conditions on the way to Cape Roberts and returned on the surveyors route which was quicker. Several seasons travel between Marble Pt and Cape Roberts have shown that the sea ice is generally better within 1 km page 20 of the coast. Some rough ice can be expected on the north side of Gneiss Pt around Dunlop Island, off the Debenham Glacier ice tongue and near Cape Roberts.

Ferrar Fjord this season contained about 30% rough ice up to 0.5 m high including multi-year sea ice plates and a snow cover about 100 mm thick. Travel was generally easy but slow. This is very different to the 1984-85 season when the Fjord contained very smooth ice, less than 10% rough ice without any "permanent" snow cover.

In New Harbour rough ice again occurred in the central harbour with much multi-year ice in Explorers Cove. The sea ice was generally smooth on the south side of the harbour near the Bowers Piedmont Glacier. We often travelled on the Piedmont between Butter Pt and Trig Herb when commuting into the Ferrar Fjord. This route was smooth, snow covered and without observed crevasses.

The sea ice offshore between Butter Pt and Cape Roberts was quite rough with ice block walls 3-4 m high in places. Several adjoining leads were found from Dunlop Island to Cape Roberts for travelling. However the route was circuitous in places.

The sea ice in Granite Harbour was very smooth on the south side and inner harbour. Low rough ice occurred in the central harbour and on the northern side.

Sea ice this season was about 3 m thick in Ferrar Fjord, New Harbour, 0.5 m thicker than in 1985. Sea ice in other parts of western McMurdo Sound seemed also to be thicker, and by a similar amount. The distribution of pressure ridges, rough and smooth ice, however, was similar to that observed previously.