Explain longshore drift.

The prevailing wind blows over the sea at an angle to the coastline, therefore it will cause the swash to run up the beach at a 45 degree angle, this will carry sediment with it which will be deposited. The backwash will then return it back into the ocean at a 90 degree angle to the coastline. This process will repeat itself and over many years sediment will undergo transportation along the coastline.