Costal

Question 1

Abrasion?

Answer 1

Waves throwing beach materials against a cliff

Question 2

Corrosion?

Answer 2

Limestone is dissolved by sea water

Question 3

Hydraulic action?

Answer 3

Air in a crack is compressed by the on-rushing wave and this will force the rock to break off

Question 4

Attrition?

Answer 4

Beach materials hitting against each other causing rounded pebbles and rocks

Question 5

Formation of a headland and bay?

Answer 5

Form in coastlines where there are hard rocks and soft rocks which causes differential erosion.
Hard resistant rocks are more difficult to erode than softer rock. Harder rock forms the headlands and softer rock is eroded back to form the bays.
The softer rock is eroded faster by abrasion and hydraulic action

Question 6

Formation of cliff and platform?

Answer 6

• waves attack at the foot of the cliff through abrasion and hydraulic action. Over times this creates a wave-cut notch
• as the notch gets bigger the cliff above is left unsupported and collapsed due to gravity
• this continues and the cliff retreats and increases in height. The gentle sloping expanse of the retreating cliff is called a wave cut platform

Question 7

Caves, arches, stacks and stumps?

Answer 7

• Waves attack areas of weakness such as a joint or fault
• a sea cave is formed in the headland and is deepened and widened over a long period of time by abrasion and hydraulic action
• the sea eventually cuts through the headland to form an arch
• waves continue to erode the foot of the arch until its roof becomes too heavy and collapses due to gravity.
• this leaves part of the headland cut off to form a stack
• the stack is then undercut by waves and collapses to form a stump

Question 8

Formation of spit/sand bar?

Answer 8

Longshore drift moves materials along the coast in a zigzag fashion. When this material reaches a break in the coastline such as river estuary or a bay it will deposit material to form a long narrow line of shingle called a sand spit. If the sand spit reaches the other side of the break then it forms a sandbar. A salt marsh forms in behind.