Icefall

Roosevelt Glacier 6940

Icefall hires 2

KhumbuIcefall

MSH06 east arm crater glacier 10-22-06

IcefallAthabascaGlacierColumbiaIcefieldAlberta1993

Icefall is a term used in glaciology to describe a portion of a glacier that exhibits rapid flow and a chaotic crevassed surface, resembling a frozen waterfall. Icefalls occur when glacier ice moves over a steep bedrock slope. Due to the rapid flow and the stress of movement over uneven terrain, the ice fractures, creating deep crevasses and seracs (towering blocks or spires of ice). This makes icefalls among the most perilous sections of a glacier for mountaineering.

Formation

Icefalls are formed as a glacier flows over a steep gradient, causing an increase in velocity of the ice flow. This rapid movement is due to gravity and the pressure of the ice mass above. As the ice accelerates, it becomes more plastic and begins to stretch. When the underlying topography is uneven or steep enough, the stress on the ice exceeds its plastic limit, leading to fracturing and the formation of crevasses and seracs.

Location

Icefalls are commonly found in high mountain ranges such as the Himalayas, the Alps, and the Rocky Mountains. Notable examples include the Khumbu Icefall on the Nepalese side of Mount Everest, which is one of the primary obstacles for climbers on the south route to the summit, and the Icefall Glacier in Alaska.

Dangers

The dynamic and unstable nature of icefalls poses significant risks to climbers and adventurers. The constantly shifting ice can lead to sudden crevasse openings or serac collapses, which can be fatal. Additionally, the route through an icefall can change from year to year or even day to day, requiring careful planning and flexibility. Despite these dangers, the beauty and challenge of icefalls make them attractive objectives for experienced mountaineers.

Exploration and Mountaineering

Navigating an icefall requires technical mountaineering skills, including the use of ropes, ice axes, and crampons. Climbers often use ladders to cross crevasses and must be constantly aware of the potential for ice movement and collapse. Expeditions will typically employ experienced guides, known as Sherpas in the Himalayas, who are skilled in finding the safest routes through the icefall.

Conservation and Climate Change

Icefalls, like all glacial features, are affected by climate change. Warming temperatures can lead to increased melting and instability within icefalls, potentially making them more dangerous to navigate. Additionally, the retreat of glaciers due to climate change can lead to the disappearance of icefalls. Conservation efforts are focused on understanding and mitigating the impacts of climate change on glaciers and their associated features.