Coasts

Question 1

When backwash > swash = _____

Answer 1

Destructive wave

Question 2

When swash > backwash = _________

Answer 2

Constructive wave

Question 3

What is a destructive wave

Answer 3

Formed by strong winds, high energy levels. Erodes beach material

Question 4

What is a constructive wave

Answer 4

Calmer weather, less powerful, don’t break as violently.

More material carried up beach than down

Question 5

What causes a tidal bulge

Answer 5

When the sun and moons gravity pull on earths ocean waters

Question 6

Abrasion

Answer 6

Waves pick up material and hurl them at base of cliff

Question 7

Hydraulic action

Answer 7

Air trapped, compresses, pressure of water weakens rock and breaks

Question 8

Solution/ corrosion

Answer 8

Acids in sea dissolve rocks e.g. - chalk and limestone

Question 9

Attrition

Answer 9

Waves smash rocks and pebbles on shore into each other - they break and gradually get smaller

Question 10

Fetch

Answer 10

Length of water waves travel

Question 11

What are sub aerial processes

Answer 11

Land based which alter shape of coastline. Combo of weathering and mass movement

Question 12

Different types of weathering

Answer 12

Freeze thaw action
Exfoliation
Biological weathering
Chemical weathering

Question 13

Exfoliation.

Answer 13

Respected action of heating and cooling rocks causing them to shed off layers

Question 14

Biological weathering

Answer 14

Plant seeds get into cracks and begin growing, put pressure on rocks causing them to fracture

Question 15

Chemical weathering

Answer 15

Hydrolysis - splitting of materials due to reactivity with water
Oxidation - Rusting

Question 16

What are the different types of mass movement (5)

Answer 16

Rockfalls 
Soil creep 
Landslides
Rotational slumping 
Mudflow

Question 17

Rockfalls

Answer 17

FTW breaks rock into smaller pieces and this can free fall

Question 18

Soil creep

Answer 18

Damp soil moves slowly downhill due to increase in mass OR as a result of freezing and thawing

Question 19

Landslides

Answer 19

After being soaked with water, cliffs made from soft rock will start to slip due to rock being lubricated

Question 20

Rotational slumping

Answer 20

Heavy rainfall makes rock heavier due to absorbing water and lubrication

Question 21

Mudflow

Answer 21

Steep slopes, saturated soil and little vegetation - rapid movement of mud downhill

Question 22

Formation of a cave, arch, stack, needle and stump

Answer 22

Cave:
Weaknesses in the rock gets eroded by hydraulic action and abrasion
Arch:
More hydraulic action and abrasion also sub serial
Stack:
Arch collapses bc too heavy - detached stack
Needle:
Thinner stack
Stump:
Eroded needle

Question 23

Formation of wave cut platform

Answer 23

Starts as wave cut notch, waves erode notch by high water mark erosion (hydraulic action + abrasion) + sub aerial (FTW) + mass movement (rockfalls)

*Explain how hydraulic action, abrasion, FTW and rockfalls occur.

Cliff retreats, wave cut platform develops and build up in beach material - sand.

Question 24

What is a blow hole

Answer 24

Roof of cave collapses, incoming waves force air to rush vertically or water to spout intermittently

Question 25

What is a geo

Answer 25

Inlet in face of cliff - created by the wave driven erosion of cliffs along faults and bedding planes in rock

Question 26

Long shore drift

Answer 26

Sediment is carried up beach by awash and backwash

Question 27

Solution

Answer 27

Minerals dissolved in sea water

Question 28

Suspension

Answer 28

Small particles carried in water

Question 29

Saltation

Answer 29

Load bounced along sea bed - small pieces of shingle

Question 30

Traction

Answer 30

Pebbles/ larger sediments rolled along sea bed

Question 31

Formation of spit

Answer 31

Spit is stretch of land that joins the main beach at one end Long shore drift and direction of prevailing wind, sediments carried up beach by smash and backwash. Deposited above the high water mark and becomes short extension of beach material connected to main beach. Longer spit created, second most dominant wind creates hook. Fastest river current helps prevent spit from expanding to form a bar. Behind spit - mud flat forms. When conditions become possible for algae and vegetation to grow, salt marshes form. Salt marshes can act as a natural coastline defence, trapping sediments and creating shallows near coast - slow down and remove energy from storm waves.

Question 32

Coastal management (7)

Answer 32

Sea wall - Built along front of cliff to protect settlement Groynes - To help prevent longshore drift Offshore rock groynes - Change direction of waves and reduce longshoremen drift Rip rap/ rock armour - Big boulders Placed along base of cliff to absorb energy from waves Revetments - Wooden slatted barrier absorbs energy from waves Gabbions - Rocks and boulders invaded in wired mesh to absorb energy from waves Beach replenishment - Making beaches higher and wider by bringing sand in from somewhere else