Wave Processes 

Transportation of Material

Different types of sediments or materials such as white sand, yellow sand, shingle (pebbles) and mud can be found along the coastline. Waves and currents constantly move these sediments up and down and along the coastline. This is called coastal transportation.

Sediment is moved by the waves in a number of ways. The figure below shows the different ways.

Traction: this is where heavier particles are slowly rolled long the sea bed.

Saltation: some materials move in a bouncing manner as they are disturbed by other particles knocking into them.

Suspension: the lighter materials can be picked up and carried within the water. Sand is mostly transported this way.

Dissolved load: dissolved chemicals will be transported in solution. Limestone (calcium carbonate) is often transported in this way. 

Diagram showing how sediments are transported.

Longshore Drift 
Materials are carried and deposited on the beach by the swash of waves. The backwash then drags the material back into the ocean. By this action, material is transported along the coastline, this process in known as longshore drift.

Longshore Drift 

Diagrams showing how material is transported along the coastline 

If the waves approach the shore parallel to the shore, the materials move up and down the beach, whereas, if the waves approaches the shore at an angle the materials are transported in a ‘zig-zag’ fashion. As a result of longshore drift, it is likely that sediments or materials will accumulate or build up at one end of the beach.