Coasts

Question 1

Types of weathering

Answer 1

• biological(plants grow in cracks)
• chemical(rocks dissolved by chemicals in water)
• mechanical(freeze-thaw)

Question 2

Weathering describes___

Answer 2

the breaking down of rocks where they are

Question 3

Mass movements describes___

Answer 3

when rocks and loose material shift down slopes

Question 4

Types of mass movement

Answer 4

• slides(down slope in a straight line)
• slumps(down a slope with rotation)
• rockfalls(material breaks apart and then rolls down slope)

Question 5

Erosion describes___

Answer 5

the wearing away of rocks using movement

Question 6

Types of erosion

Answer 6

• abrasion(rocks hit against coast)
• hydraulic action(waves breaks rocks apart)
• solution(seawater dissolves some rocks)
• attrition(rocks rub together and break into smaller pieces)

Question 7

Coastal deposition describes___

Answer 7

when material is dropped by seawater on the shore

Question 8

What causes deposition to occur at the coast

Answer 8

Constructive waves

Question 9

Longshore drift

Answer 9

transports material along coastlines

1. wind approaches the coast at an angle due to prevailing wind direction
2. the swash forces sediment up the beach at a 45 degree angle
3. the backwash falls at right angles to the coastline
4. this zig zag process continues

Question 10

Swash vs backwash

Answer 10

Swash carries material up the beach

Backwash carries material down the beach

Question 11

Types of water transportation

Answer 11

• solution(rocks dissolved in water)
• suspension(sand particles are carries along)
• saltation(small particles bounce along bed)
• traction(large rocks are rolled along bed)

Question 12

Destructive waves

Answer 12

• Weak swash, strong backwash
• Material is dragged into the sea, eroding the coast
• High energy

Question 13

Constructive waves

Answer 13

• Strong swash, weak backwash
• Material is carries onto the beach, building up the coast
• Lower energy

Question 14

Geological structure

-rock type

Answer 14

Hard rocks = resistant to erosion

Question 15

Geological structure

-joints and faults

Answer 15

Joints and faults are cracks in rocks

If rocks have joints or faults they are more vulnerable to erosion

Question 16

Geological structure

• concordant coats
• discordant coasts

Answer 16

Concordant coats are made of 1 rock type

Discordant coats are made of 2 or more rock types

Question 17

Impacts of climate on coastal erosion

Answer 17

• storm frequency
• prevailing winds
• seasonality

Question 18

Uk’s prevailing winds

Answer 18

Warm
South-westerlies
Bring Atlantic storms

Question 19

Erosional landforms

Answer 19

• headlands and bays
• caves, arches and stacks
• cliffs
• wave-cut platforms

Question 20

Erosional landform

-wave cut platform

Answer 20

1. waves erode the base of the cliff forming a wave-cut notch
2. erosion of the wave-cut notch causes the rock above it to collapse
3. waves wash away collapsed material and it starts over
4. over time events lead to the cliff retreating leaving behind a wave-cut platform

Question 21

Erosional landform

-headlands and bays

Answer 21

1. the sea hits both the hard and soft rock
2. the soft rock is eroded easier creating a bay
3. the less eroded hard rock juts out creating a headland

Question 22

Erosional landform

-caves, arches and stacks

Answer 22

Erosion at a headland
Caves
-when waves erode joints and faults in the rock
Arches
-when caves erode the way through
Stacks
-when an arch collapses

Question 23

Depositional landforms

Answer 23

• beaches
• spits
• bars

Question 24

Depositional landforms

-beaches

Answer 24

beaches are made by constructive waves depositing sand inland

Question 25

Depositional landforms | -spits

Answer 25

Spits are long fingers of sand that often have salt marshes behind them Where the river meets the sea LSD moves sediment. The river doesn't let LSD completely join to the coast

Question 26

Depositional landforms | -bars

Answer 26

Bars form when a spit grows across a bay | Lagoons often form behind bars

Question 27

Human activity effecting the coast

Answer 27

- agriculture - industry - coastal management - development(eg. settlement)

Question 28

Coastal defences | Hard engineering

Answer 28

- groynes - rock armour(rip-rap) - sea wall - gabions

Question 29

Coastal defences | -groynes

Answer 29

Wooden fences that stick out 90 degrees to the coast ADV -they stop material being transported by LSD DIS -don't stop erosion further down the coast

Question 30

Coastal defences | -rock armour(rip-rap)

Answer 30

A pile of boulders ADV - reduces erosion by absorbing wave energy - cheap

Question 31

Coastal defences | -sea walls

Answer 31

Made out of hard materials that reflect waves ADV -prevent coastal erosion and flooding DIS -expensive

Question 32

Coastal defences | -gabions

Answer 32

Are wired cages filled with rocks ADV - reduce erosion by absorbing wave energy - cheap

Question 33

Coastal defences | Soft engineering

Answer 33

- dune regeneration | - beach nourishment

Question 34

Coastal defences | -dune regeneration

Answer 34

Involves creating sand dunes ADV -reduces wave energy DIS -only small areas protected

Question 35

Coastal defences | -beach nourishment

Answer 35

Involves moving material to upper areas of the beach ADV - reduces wave energy - widens the beach DIS -threatens organisms

Question 36

Managed retreat

Answer 36

Coastal defences are removed and the sea i allowed to flood the coast which will turn to marshland which reduces erosion and flooding of land behind it ADV - cheap - no maintenance needed - provides habitats DIS -conflict about what areas are allowed to flood

Question 37

Case study

Answer 37

Dawlish Warren