Physical Processes Shaping Coastal Landscapes

Flashcards covering coastal physical processes including weathering, mass movement, wave types, and coastal erosion mechanisms.

What is weathering?

The breaking down or dissolving of rocks on the Earth's surface.

What is mechanical weathering?

The breaking down of rocks into smaller pieces without changing their chemical composition.

How does freeze-thaw weathering break down rock?

Water collects in cracks in the rock, freezes and expands at night to force the rock apart, and over time the repeated cycle causes rock fragments to break off as scree.

What is chemical weathering?

When rocks are broken down by changes in their chemical composition, such as when acidic rainwater containing $CO_2$ dissolves limestone.

What is mass movement?

The process by which cliffs collapse when large amounts of rocks or soil move all at once.

What is a rockfall?

A type of mass movement where fragments of rock broken down by mechanical weathering break off a cliff face.

What is a landslide?

A type of mass movement where blocks of rock slide along bedding planes.

What is slumping (rotational slip)?

A type of mass movement where heavy, saturated soil suddenly slips in a rotational movement.

What two factors determine the strength of a wave?

The strength of the wind and the fetch.

What is the fetch?

The distance over which the wind has blown.

What are the key characteristics of constructive waves?

They have a strong swash, weak backwash, are less frequent, deposit material (constructing the beach), and form long, gently sloping beaches.

What are the key characteristics of destructive waves?

They have a weak swash, strong backwash, are more frequent, crash downwards, erode material (destroying the beach), and form steep beaches.

What is coastal erosion?

The wearing away and removal of rocks on the coastline.

How does hydraulic power cause coastal erosion?

The force of the waves hits the cliff, compressing air into cracks in the cliff face and forcing it apart.

How does abrasion cause coastal erosion?

Waves throw sand, rocks, and pebbles at the cliff.

How does solution cause coastal erosion?

Slightly acidic seawater dissolves the cliff face.

What is attrition?

An erosion process where rocks within the water knock into each other, becoming smaller and rounder.

Why is attrition unique compared to other coastal erosion processes?

Attrition does not affect the cliff face or coastline; it only affects rocks in the water.

What two factors determine the speed of coastal erosion?

The strength of the waves and the geology (rock type) of the coastline.