A 'serac' (originally from
Swiss French ''sérac'', a type of crumbly white
cheese) is a block or column of
ice formed by intersecting
crevasses on a
glacier. Often house-sized or larger, they are dangerous to
mountaineers since they may topple with little warning. Even when stabilized by persistent cold weather, they can be an impediment to glacier travel.
Seracs are found within an
icefall, often in large, or big, numbers, or on ice faces on the lower edge of a hanging glacier.
[1] Examples of the latter in the
Alps are found on the north-east face of
Piz Roseg, the north face of the
Dent d'Hérens and the north face of
Lyskamm.
References
1. Glacier Ice, Post, Austin and Edward R. Lachapelle, , , University of Washington Press, ,