Tasman Glacier - Hochstetter Icefall

As glaciers lumber downhill over rough terrain, the brittle surface ice often forms deep cracks known as crevasses, up to 40–60 metres deep. These are a deadly hazard for alpine travellers, especially when hidden by snow. On very steep slopes, glaciers may break up into icefalls, such as Aoraki/Mt Cook’s Hochstetter Icefall, with cascades of towering, jumbled blocks of ice.