At the start of a classic valley glacier is a bowl-shaped cirque, which has escarped walls on three sides but is open on the side that descends into the valley. Cirques are where ice begins to accumulate in a glacier. Two glacial cirques may form back to back and erode their backwalls until only a narrow ridge, called an arête is left. This structure may result in a mountain pass. If multiple cirques encircle a single mountain, they create pointed pyramidal peaks; particularly steep examples are called horns. COUNT 5
QSN1 On which side is a cirque opened? ANS1 the side that descends into the valley QSN2 Where does ice start accululating in a glacier? ANS2 Cirques QSN3 What is a narrow ridge formed by two cirques eroding back to back called? ANS3 arête QSN4 What are extremely steep cirques called? ANS4 horns QSN5 How many sides are closed in a typical cirque? ANS5 three sides