Edge of sea-ice off Oates Land

This is old sea-ice that has been subjected to forces from the sea at some time, hence the broken up nature of the small pressure-ridges. Sea ice is perfectly flat when it first forms, but distant storms and ocean currents may push with enormous force at the edge. This can cause these pressure ridges which occur where the ice is pushed up and over itself. Sometimes quite eerily, the forces are so distant as to not be discernable, the ice just starts to heave and buckle in what otherwise can be calm conditons.

Picture courtesy of Mike Usher - Mike went on a Ross Sea expedition on board the Kapitan Khlebnikov in 2005.
You can purchase a selection of Mike's pictures here