Here's why:
* Cirques are formed by the erosive power of glaciers. As a glacier moves, it carves out a hollow at the head of a valley. This hollow, shaped like a bowl, is the cirque.
* The head of a glacier is where the ice originates, usually high up in mountains.
* Erosion within the cirque occurs due to the glacier's weight, the scraping of rocks embedded in the ice, and the freezing and thawing of water within cracks in the rock.
So, the next time you see a bowl-shaped basin at the top of a mountain, you'll know it's a cirque, a testament to the power of glaciers to shape the Earth's surface.
