Costal landforms

Question 1

What is deposition

Answer 1

1.) when sea reaches shallow water it drops it begins to lose energy
2.) when it has no more energy it drops its load - deposited material is called sediment
3.) usually occurs in sheltered bays or mudflats. sheltered estuaries behind the spit where water can flow.

Question 2

Freeze thaw

Answer 2

1.) water seeps into a crack in the rock
2.) at night temp fall below 0 and water becomes ice - expands.
3.) in the day ice thaws and more water enters crack and the process repeats.

Question 3

Salt weathering

Answer 3

1.) sea water contains salt
2.) once salt evaporates salt crystals will form
3.) as crystallisation - and more water added - it will expand and break the rock

Question 4

Carbonation

Answer 4

1.) rain water absorbs CO2 becoming slightly acidic.
2.) When acid rain water touches rock (containing calcium carbonate e.g chalk) it can cause a chemical reaction which dissolves the rock.

Question 5

Sliding

Answer 5

Large blocks of rock slide down a cliff face as a landslide often triggered by heavy rainfall or earthquakes.

Question 6

Slumping

Answer 6

Collapse of saturated / weak rocks often along a curved surface. Happens on clay which becomes wet and collapses.

Question 7

Rock falls

Answer 7

Fragments of rock break away from cliff often due to freeze thaw and forms scree at the bottom.

Question 8

Amount of energy in waves depends on

Answer 8

Speed of wind
Fetch
How long the wind has been blowing

Question 9

How waves are formed

Answer 9

1.) out in sea eaves more in a circular motion
2.) when wave meets the sea bed it interrupts the circular motion. the bottom of the waves slows due to friction causing wave to become more elliptical.
3.) the crest of wave rises up and eventually topples over onto the beach.

Question 10

Destructive waves - characteristics

Answer 10

Tall / high energy
Strong backwash weak swash
Has a high frequency meaning short wave length (10 - 14 per min)
Waves are quite close

Question 11

Constructive waves - characteristics

Answer 11

Slow / low lying waves
weak backwash strong swash
has a low frequency meaning large wave length (6-8 per min)
Waves are quite far apart.

Question 12

Wave cut platform

Answer 12

1.) Waves attack place between HWM and LWM - this creates a notch
2.) The notch become larger and deeper causing an overhang to form. due to abrasion and hydraulic action
3.) The overhang collapses due to gravity. The cliff retreats leaving a layer of rock exposed at low tide and converted at hight tide.
4.) This process is repeated and the cliff retreats further back. - form a rock pool.

Question 13

Dunes

Answer 13

1.) embryo dunes around deposited obstacles such as wood or seaweed.
2.) These develop and stabilise forming yellow dunes. Marram grass is used to the harsh windy weather and has adapted and formed long roots that can find water. this helps hold the plant together.
3.) In Time rotten vegetation adds organic matter yo sand making it more fertile. More diverse plant can now colonise.
4.) wind can form depressions in the sand called dunes slacks where ponds may form.

Question 14

Spit

Answer 14

1.) Longshore drift transports sand along the coast.
2.) Coastline changes shape
3.) Spit grown out into sea
4.) A change in prevailing winds and wave direction can cause a recurved end.
5.) Salt marshes and mudflats form in the sheltered water behind the spit.