Which erosional process primarily enlarges existing cirques in alpine regions experiencing freeze-thaw cycles?

💡 Explanation

When water enters pre-existing rock joints surrounding a cirque, repeated freeze-thaw cycles cause ice wedging and subsequent plucking, enlarging the cirque headwall. Therefore plucking enhanced by jointing results, rather than nivation, abrasion, or carbonation, which are less effective in this geomorphic setting.

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