Deeper cave excavation risks increased rockfalls because of which mechanism?

💡 Explanation

Excavation reduces the compressive force acting on cave walls, enabling failure via decreased hydrostatic stress confinement; therefore, rockfalls increase with depth because there's less overlying bedrock to counteract gravitational forces, rather than other weathering effects.

• When coastal bedrock subsides following glacial retreat in fjords, which outcome is most probable?
• Which process rapidly changes drainage patterns around alluvial fans?
• Which risk sharply increases when heavy tephra accumulates on glaciers?
• Which mechanism causes enhanced coastal upwelling during eastern boundary current shoaling?
• Which outcome diminishes dune migration rate when vegetation emerges?
• Which outcome arises when an extreme flood event exceeds natural levee height along a major river?