What is the main source of energy at the coast?
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What is the main source of energy at the coast?
The main source of energy at the coast is waves.
True or False?
A high tidal range concentrates wave energy on a small part of the cliff for longer.
False.
A low tidal range concentrates wave energy on a small part of the cliff for longer.
Define the term fetch.
Fetch is the distance over which wind blows to generate waves.
What are rip currents?
Rip currents are localised channels of powerful, fast-moving water that cut through breaking waves.
What are constructive waves?
Constructive waves are waves with a strong swash and weak backwash that build up the beach with a gentle profile.
What is wave refraction?
Wave refraction is the process where wave energy concentrates at headlands, increasing the rate of erosion.
How many sediment cells are there around the UK coastline?
There are 11 sediment cells around the UK coastline.
What is a sediment budget?
A sediment budget is the balance between the inputs and outputs of sediment in the coastal system.
Define the term high tidal range.
A high tidal range such as in the Bristol Channel, means that waves only reach a particular part of the cliff for a small amount of time, and less energy is focussed on that spot.
What is a low energy coast environment?
Low energy coast environments are those where the waves are less powerful and the coast is more sheltered.
Define the term weathering.
Weathering is the breakdown of rock in its place of origin (in-situ).
True or False?
Mechanical weathering is when rocks break up with no chemical changes.
True.
Mechanical weathering is when rocks break up with no chemical changes.
What is freeze-thaw weathering?
Freeze-thaw weathering is a process where water in rock cracks freezes and expands, the water then thaws. This process is repeated causing the rock to break apart.
Define salt crystallisation.
Salt crystallisation is a weathering process where salt crystals left when water evaporates exert pressure on rocks, causing them to break down.
What is exfoliation?
Exfoliation is a weathering process where thin pieces of rock flake off due to repeated expansion and contraction from temperature changes.
True or False?
Carbonation only affects igneous rocks.
False.
Carbonation affects carbonate rocks like limestone.
Define the term mass movement.
Mass movement is the downhill movement of material under the influence of gravity.
Which type of slow mass movement occurs when soil moves less than 1 cm per year due to repeated expansion and contraction?
Soil creep is a slow mass movement process where soil moves less than 1 cm per year due to repeated expansion and contraction.
What is a slump?
A slump is a form of mass movement where a large area of land moves down a slope in one piece, leaving behind a curved indented surface.
True or False?
Throughflow and runoff make cliffs unstable and increase the likelihood of mass movement.
True.
Throughflow and runoff make cliffs unstable and increase the likelihood of mass movement.
What is hydraulic action?
Hydraulic action is a group of erosion processes that occur due to the power of waves, with no involvement of rocks. Sea water forces air into cracks and joints in the rocks, which causes them to expand. This occurs repeatedly and breaks the rocks apart.
True or False?
Cavitation is an erosion process where high-pressure air bubbles in waves get trapped in the small cracks in the rock.
True.
Cavitation is an erosion process where high-pressure air bubbles in waves get trapped in the small cracks in the rock. They then implode , generating shock waves. The shockwaves weaken the rock.
Define abrasion.
Abrasion is an erosion process where breaking waves carrying sediment which scrapes against the rock surface.
Which erosion process involves sediment held in the waves rubbing together?
Attrition is the erosion process involves sediment held in the waves rubbing together. Over time this reduces the size of the sediment particles.
Define the term longshore drift.
Longshore drift (littoral movement) is the process by which large amounts of sediment are moved along the coast. The direction of longshore drift is influenced by the prevailing wind and moves the material in a zig-zag pattern.
Name the four ways material is moved in water?
The four ways material is transported in water are:
Traction
Saltation
Suspension
Solution
When does deposition occur?
Deposition occurs when the wave energy decreases.
Define high energy coastlines.
High energy coastlines are areas where waves maintain enough energy to carry larger rocks and shingle, resulting in rocky beaches.
True or False?
Waves lose energy when the wind increases.
False.
Waves lose energy when the wind slows or changes direction.