coasts

Question 1

Fetch

Answer 1

the length of time and distance over open water that the wind has blown to create a wave.

Question 2

Hydraulic action:

Answer 2

Waves hit cliffs and force air into cracks.

Question 3

Abrasion:

Answer 3

Waves pick up pebbles and hurl them against the cliff.

Question 4

Solution (corrosion):

Answer 4

The dissolving of CaCO3 rocks (e.g. limestone or chalk) by the sea.

Question 5

Attrition:

Answer 5

Pebbles carried by the waves collide with each other and become smaller and more rounded over time.

Question 6

Deposition:

Answer 6

Occurs when waves lose energy/ material carried is too large to transport with the amount of energy the wave has.

Question 7

Longshore drift:

Answer 7

Wave swash approaches the beach at a 45-degree angle (the same as the prevailing wind direction). This is in conditions where wave refraction is not complete.
Backwash is at a 90-degree angle, due to gravity.
Process repeats, moving sediment along the beach.
Smaller material is transported further as it requires less energy.

Question 8

Mechanical weathering

Answer 8

Mechanical weathering breaks down rocks by processes such as freeze-thaw, salt crystal growth, and wetting and drying of clay rich rocks.

Question 9

Biological weathering

Answer 9

Biological weathering is when rocks are broken down by plant roots, burrowing animals and nesting birds.

Question 10

Chemical weathering

Answer 10

Chemical weathering is when rocks are broken down by carbonation, oxidation, and acid rain. Usually impacts CaCO3 rock.

Question 11

Mass movement:
Slumping -

Answer 11

• waves erode the cliff base and cause instability. Rainwater permeates through the rock, saturating it, until it becomes unstable and slumps along bedding planes. Leads to a stepped appearance to the cliff.

Question 12

Mass movement:
Sliding -

Answer 12

• weathering loosens rock, which slides down off bedding planes. Leads to landslides and mudslides.

Question 12

Concordant geology:

Answer 12

Rock outcrops are parallel to the sea. Creates straighter coastlines, though can create coves, like Lulworth Cove, Dorset.

Question 12

Discordant geology:

Answer 12

Rock outcrops are at 90 degrees to the sea (on the right-hand side of the diagram). Leads to headlands and bays where there are bands of soft and hard rock interspersed with each other.

Question 12

Vegetation influences the coast by:

Answer 12

Biological weathering.
Can create sand dunes via encouraging deposition, and then stabilise them.
Can protect and preserve coastal landforms by buffering and reducing wave energy (e.g. mangroves).

Question 12

Sea level influences the coast by:

Answer 12

Flooding - a huge issue associated with rising sea level, especially considering many urban areas are situated on the coast.
Saltwater incursion
Creation of landforms (different dependent on whether sea levels are rising or falling - remember this is different in different parts of the world).

Question 13

Thermal expansion:

Answer 13

As water gets warmer it expands, so as seas warm due to climate change it will expand and cause sea levels to rise.

Question 13

Isostatic readjustment:

Answer 13

Land level rises or falls relative to the sea, so it appears that sea level is falling or rising.
Leads to relict (old) landforms.
Emergent landforms (falling sea level) = raised beaches and cliffs
Submergent landforms (rising sea level) = rias (drowned river valleys) and fjords (drowned glaciated valleys)

Question 13

Eustatic change:

Answer 13

Ice on land e.g. Greenland ice sheet or Antarctic ice sheet melts and adds water to the oceans, leading to actual sea level rise.

Question 14

People influence the coast by:

Answer 14

Settlements
Fishing
Trade
Tourism