Which mechanism causes downslope soil movement during solifluction in periglacial environments?

💡 Explanation

During solifluction, the active layer thaws, causing a loss of soil cohesion because water fills pore spaces, reducing friction between particles and leading to slow downslope movement. Therefore, thaw-induced reduction of soil cohesion is the key mechanism, rather than frost heave, channel incision, or deflation which have different requirements.

• Which risk increases when artificial levees constrict a river's floodplain during an extreme rainfall event?
• Which long-term outcome results when isostatic rebound lags behind eustatic sea-level rise?
• Which mechanism causes surface water to sink in the North Atlantic region forming North Atlantic Deep Water?
• Which outcome occurs when tectonic activity interrupts thermohaline circulation?
• Which outcome occurs when accumulated sediment compacts during subduction?
• Which outcome commonly results when river downcutting slows and lateral erosion continues within a meander bend?