Test your knowledge on explaining and describing cirques
when nivation hollows become deep enough to form glacial ice by plucking as the moving glacier pulls weathered rock from the bedrock through abrasion where abrasion rates are lower by freeze-thaw
Cirques form in the high peaks . Over time glacial ice accumulates and erodes the hollow. The steep back wall is eroded . The mass of ice increases the depth of the hollow . The cirque develops an armchair shaped cross-section with a rising rock lip . The circque can grow further as meltwater enters the bergschrund crevasse.