A question of coastal erosion and transportation

Landforms of coastal erosion

Objectives:Describe and be able to explain how the following features are formed:Cliffs and wave cut platformsHeadlands and baysCaves, arches, stacks and stumps

DESCRIBE(what can you

see)

EXPLAIN(How was

this formed)

Your task….Remember your number!No 1’s - Headland and baysNo 2’s – Cliffs and wave cut platformsNo 3’s – Cave, arch, stacks, stumps

You are to COLLABORATE by using pictures, text and other materials:

DESCRIBE EXPLAINDISCUSS - How you are going to teach others

NEGOTIATE who is going to use which resources

Note: the photos in the pack are not necessarily of the same feature

Do not try to match pictures with the text.

Explain the

formation of a

sea stack.

(6 marks)

Homework

1. Add diagrams / images to A3 sheet to show the landforms

2. Use the blog to make any additional notes to your sheet

On the figure below, a sea stack has been labelled.Mark with an arrow and label three other landforms resulting from coastal erosion.

Answer should refer to the existence of a line of weakness in a cliff face – e.g. a joint, crack that is eroded by the sea to form a cave.

Hydraulic action and abrasion are particularly responsible for making the cave bigger.

Rock is relatively hard or it will simply fall.

If there are two caves on either side of the headland, continued erosion will result in a hole being formed, joining the caves to form an arch. As further erosion takes place, the arch will eventuallycollapse, as it cannot be supported. The seaward end of the arch will form a sea stack – an isolated piece or pieces of rock, separate from the headland.

Level 1 (1-2 marks)Basic statements with limited sequence e.g. sea attacks the rock, hollow is formed, gets bigger and rock above falls.

Level 2 (3-4 marks)Clear, more developed answer with clearer, more complete sequence and more appropriate terminology e.g. waves attack a headland and erode a crack in the rock. A cave is formed due to abrasion. This gets bigger and forms an arch which collapses leaving a sea stack.

Level 3 (5-6 marks)Detailed, well developed answer with clear and complete sequence; appropriate terminology, clearly links sequence to landform

The waves erode the headland to form a cave. Through hydraulic action, abrasion and attrition the rock gets eroded to form an arch. Over many years through wave erosion and weathering the arch eventually collapses to form a stack for example the Needles, Isle of Wight.

Waves attack a crack in a headland. This is enlarged to form a cave by the pounding of the waves compressing air in the rock face and abrasion where material carried by the water is flung against the cliff. In this way, the cave is made bigger and, if there is one on either side of the headland, an arch will result when they join. Continued erosion will wear away the rock supporting the arch and this will collapse. This will leave an isolated piece or pieces of rock separated from the headland – a sea stack.

Waves attack a crack in a headland.

This is enlarged to form a cave by the pounding of the waves compressing air in the rock face (hydraulic action) and abrasion (where material carried by the water is flung against the cliff).

In this way, the cave is made bigger and, if there is one on either side of the headland, an arch will result when they join.

Continued erosion will wear away the rock supporting the arch and this will collapse.

This will leave an isolated piece or pieces of rock separated from the headland – a sea stack.

http://www.bbc.co.uk/learningzone/clips/3244.bb.wmv