Marine Processes - Transportation and Deposition

Traction

large, heavy sediment rolls along sea bed pushed by currents

Saltation

smaller sediment bounces along sea bed being pushed by currents

Suspension

small sediment is carried within the flow of water

Solution

dissolved material is carried within the water potentially in a chemical form

Process of longshore drift

• waves hit beach at an angle determined by prevailing wind

• waves push sediment in this direction and up beach in swash

• due to gravity the wave then carries sediment back down the beach in backwash

• this moves sediment along the beach over time

Why does deposition occur ?

• occurs when sediment becomes too heavy for the water to carry or if the wave loses energy

• gradual and continuous process won’t happen all at once

Two types of deposition

• Gravity Settling = the water’s velocity decreases so sediment begins to be deposited

• Flocculation = important process in salt and tidal marshes - clay particles clump together due to chemical attrition and then sink due to their high density