[4] The upper surface of the blocks are rotated backwards, forming depressions which may accumulate water to create ponds or swampy areas.
Addition of water and loss of sediment cohesion at the toe may transform slumping material into an earthflow.
Slumps frequently form due to removal of a slope base, either from natural or manmade processes.
Slumps may also occur underwater along the margins of continents and islands, resulting from tidal action or a large seismic event.
The underwater terrain which encompasses the Hawaiian Islands gains its unusual hummocky topography from the many slumps that have taken place for millions of years.
One of the largest known slumps occurred on the south-eastern edge of the Agulhas Bank south of Africa in the Pliocene or more recently.
It is a composite slump with proximal and distal allochthonous sediment masses separated by a large glide plane scar.