Cirque

Cirques are the most common landforms found in glaciated mountains, and they mark the very beginning of glacial erosion. Think of them as the birthplace of a glacier — the deep, bowl-shaped hollows carved into mountain tops where ice first accumulates and begins its slow, grinding descent.

What a Cirque Looks Like

A cirque is not a shallow depression. It is a deep, long and wide trough or basin, carved out by the weight and movement of accumulated ice. The most striking feature is its walls: they are very steep, concave, and in places drop vertically at both the head and the sides. This gives the cirque an almost amphitheatre-like appearance, scooped out of the mountain.

Where Cirques Form

Cirques are most often found at the heads of glacial valleys. As snow accumulates on mountain tops, it compacts into ice. This ice, moving down the mountain, cuts into the rock beneath it — quarrying and grinding away at the mountain top to create the basin. So the cirque is both the source of the glacier and the first landform it creates.

The Cirque Lake

Once the glacier disappears — whether through melting or retreat — the hollow it carved often fills with water. This is a common sight within cirques. Such lakes are called cirque lakes or tarn lakes. The steep walls that once held the ice now hold still water, giving many high mountain regions their characteristic blue, bowl-shaped lakes.

Stepped Cirques …