Coastal Processes

Question 1

Wave types

Answer 1

Constructive and destructive

Question 2

What is a constructive wave

Answer 2

strong swash and weak backwash.
the strong swash brings sediments to build up the beach.
the backwash is not strong enough to remove the sediment.
the waves are low and further apart.

Question 3

Destructive wave features

Answer 3

weak swash and strong backwash.
the strong backwash removes sediment from the beach.
the waves are steep and close together.

Question 4

What is the ‘fetch’

Answer 4

How far a wave has travelled

Question 5

Types of mass movement

Answer 5

Rockfall
Mudflow
Landslide
Rotational slip

Question 6

What is rockfall

Answer 6

Bits of rock fall off the cliff face

Question 7

What is mudslide

Answer 7

Saturated soil (soil filled with water) flows down a slope

Question 8

What is a landslide

Answer 8

Large blocks of rock slide downhill

Question 9

What is rotational slip

Answer 9

Saturated soil slumps down a curved surface

Question 10

Types of erosion:

Answer 10

Hydraulic action
Abrasion
Attrition
Solution

Question 11

What is hydraulic action

Answer 11

The sheer power of the waves smashes against the cliff, air gets trapped into the cracks of the rocks and then the rocks break apart

Question 12

What is abrasion

Answer 12

When pebbles grind across the rock platform like sand paper and become smooth

Question 13

What is attrition

Answer 13

When rocks in the sea knock against each other, they break apart become smaller and more rounded

Question 14

What is solution

Answer 14

When the sea water that is slightly acidic dissolves certain tyoes of rocks like chalk and limestone cliffs

Question 15

What is Deposition

Answer 15

When the sea loses energy and it drops the material that it has been carrying

Question 16

Why does ‘deposition’ happen

Answer 16

Waves slow down and lose energy
Shallow water
Sheltered areas (bays)
Litte or no wind

Question 17

What is a wave cut platform

Answer 17

A wave-cut platform, shore platform, coastal bench, or wave-cut cliff is the narrow flat area often found at the base of a sea cliff or along the shoreline of a lake, bay, or sea that was created by erosion

Question 18

How are wave cut platforms formed

Answer 18

1) sea attacks base if the cliff
2) wave cut notch is formed by erosion (hydraulic action and abrasion)
3) as the notch increases in size the cliff becomes unstable and collapses
4) backwash carries away the eroded material, leaving a wave-cut platform
5) proccess repeats

Question 19

Crack ——-> Stump Formation

Answer 19

1) Cracks are widened in the headland by hydraulic action and abrasion
2) As the waves continue to slam against the cracks it begins to open up a cave
3) The cave becomes larger and eventually breaks through the headland to form an arch
4) the base of the arch continually becomes wider, until its roof collapses this leaves a stack
5) The stack is undercut at the base until it collapses to form a stump

Question 20

What are ‘spits’

Answer 20

A spit is an extended stretch of beach material that projects out to sea and is joined to the mainland at one end. Spits are formed where the prevailing wind blows at an angle to the coastline, resulting in longshore drift

Question 21

How are spits formed

Answer 21

1) Sediment is carried by longshore drift.
2) When there is a change in the shape of the coastline, deposition occurs. A long thin ridge of material is deposited. This is the spit.

3) A hooked end can form if there is a change in wind direction.

Waves cannot get past a spit, therefore the water behind a spit is very sheltered. Silts are deposited here to form salt marshes or mud flats.