Question

Name three erosional land forms explaining how they are formed.

Answer 1

Erosional landforms include headlands, bays, caves, arches, stacks, stumps and wave-cut platforms. There are also depositional landforms such as beaches, spits and bars.

[In the question u need to explain about three only]

• Sea cliffs
• Wave-cut platforms
• Sea stacks

1. Sea cliffs

Cliffs are usually formed because of processes called erosion and weathering. On sea cliffs, sediment becomes part of the seafloor and is washed away with the waves. On inland cliffs, sediment is often carried away by rivers or winds. Larger rocks broken off by sediment are called scree or talus.

A sea cliff is a steep coastal slope created by the erosive power of waves at its base (Bird, 1969; Zenkovich, 1967). As rock removal continues, the coastal slope eventually becomes oversteepened and its weight causes collapse in the form of rockfalls, landslides, or other mass movement.

2. Wave-cut platforms

Wave-cut platform, also called Abrasion Platform, gently sloping rock ledge that extends from the high-tide level at the steep-cliff base to below the low-tide level.

It develops as a result of wave abrasion; beaches protect the shore from abrasion and therefore prevent the formation of platforms.

A wave-cut platform is formed where a seacliff is eroded by marine action, meaning waves, resulting in the deposition of cliff material and formation of a bedrock area where erosion occurred.

If sea level rises rapidly this area will be covered with water.

3. Sea stacks

Stacks are formed over time by wind and water, processes of coastal geomorphology.

They are formed when part of a headland is eroded by hydraulic action, which is the force of the sea or water crashing against the rock. Eventually, erosion will cause the stack to collapse, leaving a stump.

Coastal erosion or the slow wearing of rock by water and wind over very long periods of time causes a stack to form. All sea stacks start out as part of nearby rock formations. Millennia of wind and waves hit the rock and break it down.