Which mechanism leads to a tarn formation within a glacial cirque after deglaciation?

💡 Explanation

When a glacier erodes a cirque, the over-deepening mechanism results because glacial plucking and abrasion carve out steeper and deeper hollows, creating an enclosed depression. Therefore a tarn forms due to the depression filling with meltwater, rather than rebound, weathering, or solifuction, which require alternate processes.

• Which soil profile development is increased where groundwater fluctuates near surface?
• Which mechanism primarily causes cirque expansion in periglacial environments?
• Which mechanism primarily isolates an oxbow lake during flood recession?
• Which mechanism causes episodic draining of ice-dammed lakes during glacial retreat?
• Which outcome primarily results in arid landscapes downstream of large alluvial fans due to water management?
• Which impact does increased freshwater input from glacial melt have on North Atlantic gyre circulation?