coastal depositional landforms Flashcards
What is a storm beach?
At the backshore of the beach.
A raised ridge and vegetation may grow in it.
The last point where the waves will hit, during a storm where the wave energy is highest
What is a Berm?
A series of small ridges that form on a beach, Deposited by the swash of constructive waves. Looks like a speed bump and is a high tide mark, usually formed with seaweed.
What are ridges and runnels?
Series of a ridges and troughs running parallel to the coast. formed at the water’s edge. More pronounced troughs and in a different direction to ripples
What are ripples?
Small elongated ridges forming on loose sand.
What are cusps?
Semi circular, they occur when the backwash takes the material away.
What is a spit and how is it formed?
A spit forms at a drift aligned beach, where the prevailing winds approach the beach at an angle. This leads to a zigzag movement of sediment on the beach known as longshore drift. When there is a change in coastline direction or an estuary where the river meets the sea, sediment is forced to deposit out to sea forming a spit. When there is a second dominant wind direction this leads to the formation of a hooked end. Behind the spit, the water is now more sheltered and silt and mud accumulates to form a salt marsh. This helps to stabilise the shingle spit. Over time, dunes may form on the spit.
What is a bar and how is it formed?
A bar is a beach connecting two headlands and forms when a spit extends over a bay due to the direction of longshore drift.
When the spit grows to eventually meet another headland, this spit forms a bar. This traps sea water behind to form a lagoon. This is brackish water.
Over time, silting and infilling will take place in the lagoo, meaning sediment builds up and the lagoon becomes smaller
