The main sources of sediment along coasts are: (1) the coastal landforms themselves, including cliffs and beaches; (2) the nearshore zone; and (3) the offshore zone and beyond. The erosion of coastal landforms, especially cliffs, can locally provide abundant sediment in environments with high wave energies (especially where unconsolidated sediments are being eroded).

Land-derived sediment can be provided by mass movement (e.g., rockfalls, landslides, and debris flows), especially where cliffs composed of material susceptible to such processes are being actively undercut. In periglacial environments, such as the Arctic coast, gelifluction is a particularly important means of transporting sediment into the nearshore zone, while in other high-latitude