Sandshed: The Sand Is on the Move!
There is a constant flow of sand from the land into the ocean. Watershed run-off and bluff and hillside erosion bring sand to the beach. Sand grains travel southward down the coast, while finer particles of sediment are carried and deposited further out to sea.
Along the way, sand is washed ashore, temporarily resting on beaches, until it is re-suspended in the ocean by wave action or wind. The one-way journey down the coast ends when sand is blown inland forming sand dunes, or more commonly, when it flows into a submarine canyon. This deep underwater feature is essentially the dead end of a littoral cell, where sand is deposited for the long-term and, for practical purposes, lost.
A littoral cell is a distinct area of the coastline where sand enters the ocean, flows down the coast, and then is removed from the system. Permanent loss of sand occurs at the end of the littoral cell when it flows into a submarine canyon or, less frequently, when it accumulates on shore as part of a sand dune. The amount of sand available to…
Credit: Dave Hubbard and UCSB Sea Grant Team