Physical Environments 2

LITHOSPHERE
COASTAL

Higher
Geography

COASTAL LANDSCAPES

formation of erosional and depositional features in coastal landscapes:

1. Wave Cut Platform

2. Headland and Bay

3. Cave / Arch / Stack

4. Spit

5. Bar

6. Tombolo 

Coastal Processes

1. I can explain how the sea erodes the landscape by the processes of:

1. Hydraulic Action

2. Abrasion

3. Attrition

4. Solution

https://www.twigscotland.com/film/coastal-processes-waves-1118/
2.26 minutes

https://www.twigscotland.com/film/coastal-processes-1152/
2.25 minutes

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Coastal Processes of Erosion

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Hydraulic action – force of the waves crashing against the shore and cliffs forces air into cracks in the rock (1), causing the air to implode, the shockwave erodes the rocks (1).

Abrasion – wearing away of cliff by sand, shingle and pebbles (1) hurled against them by waves (1).

Attrition – waves cause eroded material to smash against each other (1). Gradually the eroded material becomes smaller and rounder aiding abrasion (1).

Solution – dissolving of certain rock types (1) by the naturally occurring acid and salt in the sea water (1).

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https://timeforgeography.co.uk/videos_list/coasts/marine-erosion-processes/
2.30 minutes

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Coastal Processes of Deposition

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1. I can explain how the sea shapes the landscape by the processes of:

1. Longshore Drift

Coastal Processes of Deposition

Longshore Drift

The swash moves up the beach at an angle (1) due to the direction of the prevailing winds (1).

The backwash moves back down the beach at a right angle (1) due to gravity (1).

1. Wave Cut Platform

Cliffs form where there is harder more resistant rock (1) such as granite / chalk (1).

Wave energy is at its greatest when a high, steep wave breaks at the foot of a cliff (1). Continued erosion causes the notch to become larger over time (1)

Weaknesses such as joints, faults or cracks in cliffs (1) are undercut by erosion to form a wave-cut notch (1) the rock above overhangs over the notch and, as erosion continues, the notch enlarges (1) until the unsupported overhang collapses due to the weight (1).

The new cliff face is then eroded and through time, the cliff retreats inland, leaving a gently-sloping rocky surface called a wave-cut platform (1), which extends out to sea away from the cliff (1).

The platform is abraded by rock materials, with rock pools and potholes forming, evident at low tide (1).

An example of a cliff is Seacombe Cliff (1). 

1. Wave Cut Platform

https://timeforgeography.co.uk/videos_list/coasts/formation-of-a-wave-cut-platform/
2.15 minutes

2. Headlands & Bays

Headlands and bays form along discordant coastlines (1). This is when alternating bands of rock do not run parallel to the sea (1).

Alternating bands of hard and soft rock such as chalk (1) (hard) and clay (soft) are eroded at different rates (1). This is called differential erosion (1).

A headland is an area of hard rock which juts out into the sea (1) and a bay is a sheltered area of softer rock between headlands (1).

Constructive waves build a small beach in the sheltered bay between the headlands (1).

An example of a Headland and bay is Swanage Bay (1)

https://timeforgeography.co.uk/videos_list/coasts/Large-scale-erosional-landforms/
1.16 minutes

2. Headlands & Bays