|1.||corrie, Also called: cwm a semicircular or crescent-shaped basin with steep sides and a gently sloping floor formed in mountainous regions by the erosive action of a glacier|
|2.||archaeol an obsolete term for circle|
|3.||poetic a circle, circlet, or ring|
|[C17: from French, from Latin circus ring, circle, |
|cirque (sûrk) Pronunciation Key
A steep, amphitheatre-shaped hollow occurring at the upper end of a mountain valley, especially one forming the head of a glacier or stream. Cirques are formed by the erosive activity of glaciers and often contain a small lake.
(French: "circle"), amphitheatre-shaped basin with precipitous walls, at the head of a glacial valley. It generally results from erosion beneath the bergschrund of a glacier. A bergschrund is a large crevasse that lies a short distance from the exposed rock walls and separates the stationary from the moving ice; in early summer it opens, exposing the rock at its base to diurnal changes of temperature. Frost action then causes rapid disintegration of lower rock, which causes the upper rock to avalanche and produce an almost vertical head wall. Resulting rock material is embedded in the glacier and scours a concave floor, which may contain a small lake (tarn) if the glacier disappears. Expansion of neighbouring cirques produces sharp aretes, cols, and horns. Because glaciers must originate above the snowline, a survey of the elevations of ancient cirques provides information on climatic change and on the former position of the snow line.
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