Coastal features Flashcards
What type of feature is a beach?
Depositional feature
What is a tombolo?
An island connected by a sand shingle to the mainland.
What is a bar?
When a spit joins the land to create land across the whole face. A lagoon forms behind it, and then over many years marshland forms.
What is the difference between impermeable and permeable rocks?
Impermeable rock means water can’t pass through but can soak up the water so that the rocks become saturated. Permeable rock means that water can pass through.
How is a spit formed?
Spits are formed by the deposition of sediment from longshore drift. Longshore drift erodes the beach by swash in the direction of the wind, and perpendicularly by backwash. The combined movement of swash and backwash moves sediment along the beach in a zig-zag pattern. When the coastline changes direction longshore drift is interrupted and sediment is deposited. Therefore, a spit grows in this area. The change in coastline direction is usually due to a river mouth, hence why many spits occur by river mouths.
What is a macro feature?
A large scale feature like a beach.
What is a micro feature?
A small scale feature like berms or storm ridges.
What is a wave cut notch?
An indentation cut into a sea cliff at water level by wave action.
What is a wave cut platform?
the flat rocky area left behind when waves erode a cliff away
How is a stump formed?
Large crack opened up by hydraulic action
Crack grows into cave by hydraulic action and abrasion
Cave continues to expand
Cave breaks through headland forming a natural arch
Arch is eroded and collapses
Leaves a tall rock stack
The stack is eroded at the base by abrasion and hydraulic action, and on face by weathering, to form a stump.
