Serac

The word “serac” originated from the Swiss French sérac, which is a type of a crumbly white cheese. Seracs are needle-like towers, individual blocks, or columns of ice on the surface of a glacier. Their height varies between few meters to tens of meters. They can be found within icefalls or on the lower edge of hanging glaciers (e.g., Post and Lachapelle, 2000). Seracs are commonly formed by intersecting crevasses where the glacier is periodically broken as it passes over a steep slope. They can cause disastrous hazards and are dangerous to mountaineers due to rapid toppling often with little advance warning time.