Geography GCSE AQA A

Plus de détails

coast

par Erin Kimbrell

Making Decisons about Disruptive Behavior

par Morgan Anderson

External Geological Processes and Landscapes

par Josep Maria Rosell Hutagaol

SNC

par Fraser Zhang

Geography The Coastal Zone

Tombolo

Bar

Spits

Salt Marshes

Beaches

All Coastal Key Terms

Deposition

When the sea loses energy, it drops the sand, rock particles and pebbles it has been carrying. This Process happens when the swash is stronger than the backwash and is associated with constructive waves

Backwash

The water drains back down the beach

Swash

The water rushing up the beach

Fetch

The distance the wind blows over

Case Studies

Old Harry And Wife

Mappleton

Sea Defences

Soft Engineering

Bastions

Gabions

Beach Building

Hard Engineering

Revetement

Groynes

Offshore breakwater

Sea Wall

Rip Rap

Movement Of Material Along Coasts

Saltation

Load is bounced along the sea bed, eg small pieces of shingle or large sand grains. Currents cannot keep the larger and heavier sediment afloat for long periods.

Traction

Pebbles and larger sediment are rolled along the sea bed.

Solution

Minerals are dissolved in sea water and carried in solution. The load is not visible. Load can come from cliffs made from chalk or limestone, and calcium carbonate is carried along in solution.

Suspension

Small particles are carried in water, eg silts and clays, which can make the water look cloudy. Currents pick up large amounts of sediment in suspension during a storm, when strong winds generate high energy waves.

Lonshore Drift

The direction of prevailling wind causes the swash of the waves to carry material up the beach at an angle. The backwash then flows back to the sea in a straight line at 90°. Continual swash and backwash transports material sideways along the coast.

Erosion

Features

Cliffs

Stump

Stack

Arch

Cave

Cracks

Wave-Cut Platforms

Wave-Cut Notches

Bays

Headlands

Processes

Geology

Imperable

Permable

Subtopic

Sub-aerial Processes

Biological Weathering

Human Activity

Weathering

Freeze-thaw

Chemical Weathering

Marine Processes

Abrasion/Saltation

Bits of rock and sand in waves grind down cliff surfaces like sandpaper.

Corrosion/Solution

Acids contained in sea water will dissolve some types of rock such as chalk or limestone.

Attrition

Waves smash rocks and pebbles on the shore into each other, and they break and become smoother.

Hydraulic Action

Air may become trapped in joints and cracks on a cliff face. When a wave breaks, the trapped air is compressed which weakens the cliff and causes erosion.

Coastal geography covers several key processes and features, including the deposition of materials that form various coastal landscapes like spits, salt marshes, beaches, and tombolos.