Erosional Features

Question 1

Blowhole

Answer 1

A blowhole is formed as sea caves grow landwards and upwards into vertical shafts (if overlying rock of a cave collapses) and expose themselves towards the surface. During storm high tides, seawater can be blown out of these blowholes with considerable and spectacular force.

Question 2

Caves, arches, stacks, and stumps

Answer 2

Erosional landforms. The erosion of rocks (such as limestone and chalk) exploits any lines of weaknesses (joints, faults, and cracks) which are further eroded by hydraulic action and abrasion to form caves. An arch is formed where two caves join up or a single cave is eroded through the headland. When the top of the arch collapses, it leaves behind a pillar of rock (a stack) which is eroded until it only appears above the surface at low tide (a stump).

Question 3

Wave-cut notch

Answer 3

Erosional feature formed when waves break against the foot of the cliff, concentrating erosion close to the high tide line, causing undercutting of the cliff.

Question 4

Wave-cut platform

Answer 4

Erosional feature formed due to the expansion of the wave-cut notch causing the cliff above it to become more unstable and collapse. The wave-cut notch migrates inland and the cliff retreats, leaving behind flat and usually submerged platform.