Costal Sediment Sources

Question 1

What are the 3 sources of coastal sediment?

Answer 1

Terrestrial

Offshore

Human

Question 2

What is terrestrial sediment?

Answer 2

This is sediment that came from the land including fluvial deposition, weathering and mass movement, marine erosion, aeolian deposition and longshore drift

Question 3

What is fluvial Deposition?

Answer 3

This is deposition carried out by rivers

Rivers transport sediment obtained via erosion, mass movement and weathering

As the river meets the sea it has a reduction in forward energy as it is prevented which then causes energy to dissipate resulting in deposition

Question 4

What are 2 examples of mechanical weathering?

Answer 4

Freeze thaw- expands 9%

Salt crystallisation

Question 5

What is Van’t Hoff’s law?

Answer 5

10 degree increase in temperature = 2.5x increase in rate of chemical reactions

Question 6

What is marine erosion?

Answer 6

Using the energy of waves to shape the coastal landscape

Question 7

What is hydraulic action?

Answer 7

when water is forced into cracks & joints breaking the rock apart

Question 8

What is pounding?

Answer 8

The mass of breaking wave exerts pressure on the Rock, weakening it

Question 9

What is abrasion?

Answer 9

When the waves launch rocks within the wave at the rock, wearing away at it

Question 10

What is solution?

Answer 10

When the salts and acid in water dissolve minerals

Question 11

How does climate impact the rates of solution?

Answer 11

As the climate warms there is more CO2 and as a result more acid rain and therefore more solution

Question 12

What is attrition?

Answer 12

When rocks crash into each other and break into smaller pieces

Question 13

What are mass movements?

Answer 13

When forces acting on a slope (gravity) are greater than the forces keeping the sediment on the slope (friction)

Question 14

What are rock falls?

Answer 14

When rocks detached by weathering fall down the slope

Question 15

What are landslides?

Answer 15

Layers slide sue to saturation & undercutting

Question 16

How fast do winds have to be for Saltation and surface rolling?

Answer 16

40km/h

Question 17

How does the wind Carry sand?

Answer 17

The wind raley carries sand in suspension due to its weight

Sand abrasion only occurs in heights up to 1m

Question 18

What impact does sand abrasion have on rocky Coastlines?

Answer 18

The effects of sand abrasion scales with wind velocity

usually not much impact

Question 19

Explain the process of longshore drift?

Answer 19

The swash of the waves travels in the direction of the wind vertically up the beach

Backwash then comes straight down due to gravity

Attrition occurs along the process so sediment becomes smaller and more rounded as distance increases

Question 20

When does marine deposition occur?

Answer 20

Marine deposition occurs in low energy environments such as estuaries & lagoons

Question 21

What is beach nourishment?

Answer 21

The process of taking sad from the bottom of the ocean and pumping it on to the beach

the goal is to create a wide sandy beach that can absorb energy and prevent coastal erosion

Question 22

What is beach nourishment?

Answer 22

The process of taking sad from the bottom of the ocean and pumping it on to the beach

the goal is to create a wide sandy beach that can absorb energy and prevent coastal erosion

Question 23

What happens to beach nourishment?

Answer 23

As soon as the sand is pumped onto the beach it is subject to Longshore drift