Which mechanism causes bedrock erosion underneath a cirque glacier?

💡 Explanation

When ice flows across bedrock under a cirque glacier, abrasion occurs because embedded rocks and debris in the ice act like sandpaper, grinding the rock surface. Therefore, abrasion causes erosion beneath the glacier, rather than chemical weathering, freeze-thaw cycles, or wind scour which have only minor effects at the glacial base.

• Which erosional mechanism primarily shapes the steep U-shaped valleys characteristic of Norwegian fjords?
• Which erosional process is accelerated when freeze-thaw cycles occur within a cirque formation?
• Which process explains differences in fjord sill depth and isostatic rebound rates?
• Which phenomenon causes regional uplift before a Plinian volcanic eruption?
• Which risk increases when anticyclonic conditions disrupt Hadley cell patterns?
• Which consequence results when coastal mountain ranges force orographic lift?