Coastal Systems - Mass Movement

Large-scale loss of rock coherence at the coast may result in movement of substantial material quantities under gravity onto a shoreline.

The main kinds of this mass movement are:

Run-off: when heavy rain washes material from the surface of a cliff over the edge and down onto the shore.

Landslide: an unsupported mass of rock or cliff material collapses onto the beach.

Slumping: usually unconsolidated cliff material (boulder clay) detaches at the cliff face along a slip plane and slide down onto the shore, usually after heavy rain has lubricated the weakness and made the material heavier.

Soil creep: the mass effect of individual particles taking a downwards trajectory over time from a cliff face as a result of wave-impact, rain splash, weathering and gravity.