Pressure ridges

These pressure ridges occur at the edge of the ice shelf near Scott Base. They were formed by the collision of sea ice against the low ice shelf margin, the latter at this point being only a few metres above water level. The ridges display a myriad of forms which, on a sunny evening with low light, are stunningly beautiful. Cracks which form within the ridges provide conduits for Weddell seals to haul out onto the ice shelf and give birth to pups. Scott Base staff have marked out a route through the pressure ridges, allowing visitors and residents an opportunity to experience an area of incredible beauty.

Pressure ridges
Aerial view of the pressure ridges near Scott Base. On the right is the McMurdo Ice Shelf; and on the left sea ice.
Pressure ridges
Seaward side of pressure ridges with Mt Erebus in the background.
Pressure ridges
Ice-shelf side of pressure ridges with Mt Erebus in the background. The surface of the ice shelf here is only a few metres above sea level.
Pressure ridges
Pinnacles in the pressure ridges frame Mt Discovery in the background.
Pressure ridges
View through a pressure ridge toward the volcanic cone of Observation Hill.
Pressure ridges
Tidal movements allow a moat to form in the sea ice adjacent to the ice shelf.
Pressure ridges
View of Scott Base from the pressure ridges.
Pressure ridges
Chaotic blocks of ice in the pressure ridges frame Minna Bluff in the background.
Pressure ridges
Up-thrust slab of sea ice.
Pressure ridges
Sea-ice slabs deforming under their own weight.
Pressure ridges
Ice towers, backlit by the late evening sun.
Pressure ridges
Solid flat slabs of sea ice thrust up into a wall-like feature.
Pressure ridges
Upturned ice floe, backlit by the sun, with Observation Hill in the background.
Pressure ridges
Folded ridge of up-thrust sea ice, deforming under its own weight.
Pressure ridges
Layering in sea ice is enhanced by the backlighting from the sun.
Pressure ridges
Upturned floe having the appearance of a weird animal.
Pressure ridges
Upturned floe, overhanging and ready to collapse.
Pressure ridges
Slabs of sea ice, tilted on end to form a barrier.
Pressure ridges
Recently installed wind-farm serving McMurdo Station and Scott Base.
Pressure ridges
Shadowy ice pinnacles with Mt Discovery in the background.
Pressure ridges
Arcuate crack in upturned floe.
Pressure ridges
Snow dunes comprising granular snow; reminiscent of sand dunes.
Pressure ridges
Cross-lamination picked out by low light in a snow dune.
Pressure ridges
Weddell seal that has hauled out via a crack on the ice shelf side of the pressure ridges.
Pressure ridges
Weddell seal pup peers over its motherís body.
Pressure ridges
Another Weddell seal pup with mother.
Pressure ridges
Weddell seal on its back with raised flipper.
Pressure ridges
A snow basin within the numerous pinnacles of the pressure ridges.
Photos Michael Hambrey, November and December 2010.