coasts eq2

Question 1

what are waves caused by?

Answer 1

friction between wind and water, with some energy being transferred into the water.

Question 2

Waves depend on a number of factors:

Answer 2

• the strength of the wind
• Water depth
• the duration the wind has been blowing
• the distance of sea it has travelled over (the fetch)

Question 3

Where in the UK do we experience the largest waves?

Answer 3

Cornwall because the prevailing wind is from the South west and the fetch from Florida to Cornwall is 4000 km.

Question 4

How do waves form?

Answer 4

by the wind blowing across the surface of the water. Initially, the blowing wind will create ripples and these will then turn into waves. As waves reach the coast the lower part of the wave will slow down due to friction. The upper part of the wave then falls forward and breaks onto the beach

Question 5

Why do waves break at the shoreline?

Answer 5

• the crest of the wave begins to move forward much faster than the wave trough.
• The trough experiences friction with the sediment on the sea bed and therefore slows even more.
• Eventually the crest outruns the trough and the waves topples.

Question 6

marine processes

Answer 6

those associated with the action of waves. This includes erosion, transportation and deposition.

Question 7

erosion

Answer 7

Erosion refers to the wearing away of the land surface and removal of materials by river and seawater, ice and wind. There are four main processes of erosion along the coast. These are hydraulic action, abrasion and attrition and solution ( Corrosion).

Question 8

What does geomorphic mean?

Answer 8

Relates to the formation and shaping of landforms and landscapes by natural processes such as weathering, mass movement transportation and erosion

Question 9

weathering

Answer 9

The breakdown or disintegration of
rock in situ ( its original place). As a process, weathering leads to the transfer (flow) of material.

Question 10

mass movement

Answer 10

The downhill movement of material under the influence of gravity.

Question 11

coastal sediment or littoral cell

Answer 11

system by which sediment is sourced, transported and deposited within a part of the coast.

They appear as a coastal system because sediments are derived from estuaries and coastal erosion, transported by longshore drift and deposited in the form of beaches, bars and spits etc.

Question 12

sources

Answer 12

places where sediment is generated.

Question 13

transfer zones

Answer 13

places where sediment is moving along the shore

Question 14

sinks

Answer 14

locations where the dominant process is deposition

Question 15

dynamic equilibrrium

Answer 15

Under natural conditions the systems operate in a state of dynamic equilibrium with sediment inputs balancing outputs to sinks.

Question 16

negative feedback

Answer 16

maintains balance e.g wave erosion causes rock falls which the protects the base from further erosion.

Question 17

positive feedback

Answer 17

changes the balance until a new equilibrium is reached e.g sand dunes are damage during a storms causing a “blowout” ( depression/hollow), allowing wind to move sand away, preventing marram grass from re-growing= more erosion!

Question 18

sub-aerial processes

Answer 18

land-based processes which alter the shape of the coastline. These are a combination of weathering and mass movement.

Question 19

storm berm

Answer 19

elivated ridge on sea

Question 20

constructive waves

Answer 20

• low and flat
• strong swash weak backwash
• 6-9 times per minute

Question 21

destructive waves

Answer 21

• weak swash strong backwash
• 10-15 times per minute
• erosion during storms

Question 22

wave cut notch

Answer 22

curved indention of about 1-2m high extending alom gthe base of a cliff

Question 23

wave cut platform

Answer 23

flat rock surface exposed at low tide extending out to sea from the base of a cliff