coast

Question 1

name and describe the 2 types of wave

Answer 1

constructive

• long wave length = less that 10 per min
• build up the beach
• less than 1m in height
• big swash & small back wash
• sediment
• not a lot of energy

destructive

• short wave length = more than 10 per min
• take away from the beach
• more than 1m in height
• small swash and big backwash
• sand
• lots of energy

Question 2

define coast and fetch

Answer 2

coast = boundary between land and sea
dynamic region = constantly changing
waves cause change

fetch = distance the wind is blown over the sea

Question 3

define wave and what factors influence it

Answer 3

wave = a movement of energy

depends on

• fetch
• strength of wind
• time taken for wind to blow

Question 4

how is a wave formed

Answer 4

result of friction from wind blowing over sea

break as approach land

bottom of wave touches sand = friction & slow down

top of wave continues (higher and steeper) then topples over

Question 5

what is the difference between erosion and weathering?

Answer 5

erosion = wearing away of land and removal of beach or dune sediments

weathering = the breaking down of sediment due to natural causes either biological chemical or physical

Question 6

what are the 4 types of erosion

Answer 6

attrition = stones rubbing and becoming smaller / rounder

hydraulic action = waves eroding cliffs through pressure in air cracks

abrasion = rocks being throw and cliff and chipping

corrosion = dissolving of rocks

Question 7

what speeds up erosion

Answer 7

soft rock
big fetch
destructive waves
little sea defence

Question 8

effects of erosion of people

Answer 8

tax for sea defence
buildings destroyed
loss of land
smaller towns and beaches

Question 9

define physical chemical and biological weathering

Answer 9

physical
disintegration of rock into smaller pieces
caused by physical processes
no change to chemical composition of the rock

chemical
depositon of rock
caused by a chemical change wthun the rock

biological
action of plants and animals on land

Question 10

explain the types of weathering

Answer 10

physical : freeze thaw and salt crystal growth

salt crystal

• salty water enters cracks in cliffs
• water evaporates
• salt is left
• widens cracks and breaks cliff

freeze thaw

• water freezes in cracks
• solid = larger and expands crack
• rock breaks due to pressure

chemical

acid rain

• caused by pollution and sulphur
• gas in atmosphere mixes with rain
• rain becomes acidic
• kill fish, trees and coastline

biological

• tree roots
• animals burrow into ground

Question 11

describe 2 types of mass movement

Answer 11

rock fall
weakened rock falling

slumping
rain on rock increase mass
saturation
rock and land sliding down cliff

soil creep
heavy soil moves downward
gravity
long time frame

Question 12

what is LSD

Answer 12

movement of rock and down the beach from the prevailing wind. backwash is at 90 degree angel to wind

Question 13

describe is cliff recession

Answer 13

wearing away of rock due to waves
(durlston bay, Swindon)

-waves hit against bottom of cliff 
        (waves = acidic / destructive)
-gradually erode it
-wave cut notch is formed, 
-wave cut platform is and that isn't eroded
-cliff of top weakens 
-top falls into sea = attrition

Question 14

what are coastal erotional features

Answer 14

characteristics and formations of headleands bays caves etc

Question 15

describe the process from cliff to stump

Answer 15

• arosion wears away bottom of cliff that sticks out
• cracks occure by waves
• a cave is formed from hydraulic action
• turns into an arch
• then stack (old Harry)
• then stump

occurs in durdle door, dorset with Portland limestone

Question 16

what is a spit and describe the process of how its made

Answer 16

a long narrow strip of sand
from the land into sea
caused by LSD

• LSD transports sand and pebbles along beach
• change in coastline shape or wind direction
• sediment extends out forming a strip
• weak current = sand is deposited &builds up
• hooks are formed if wind direction changes

Question 17

what are bars and tombolos

Answer 17

bar = spit connecting two headlands 
tombolo = spit connecting to an island

Question 18

headlands

bays

Answer 18

land that stick out due to surrounding land being eroded

bays soft rock that has indented the land

Question 19

hard engineering examples

Answer 19

blackpool sea wall

• good at protecting
• expensive £5000-£10000 per linear M

Eastbourne groynes

• prevents sediment leaving beach
• quite cheap = £2000 per m of wood
• exposes other areas of coastline

Dawlish warren rip rip

• rocks absorb wave energy
• quite cheap = £1000 - £3000 per M

Question 20

soft engineering examples

Answer 20

doesn’t involve building, looks at tourism and nature of rocks

carlyton bay beach replenishment

• sand reduces waves energy
• maintains tourism
• cheap = £2000 per m2

managed retreat san mateo

• housing isn’t eroded
• copensatiion is expansive

cliff regarding Swanage bay

• reduces slippage
• doesn’t potect cliff foot

Question 21

how can furcating predict coastal flooding

Answer 21

• sea levels
• rain fall
• patterns
• geology

to prepare

Question 22

building design

Answer 22

• safe bag
• steps
• electronics us
• water storage
• hard floors

Question 23

example of a place suffering from coastal erosion

Answer 23

Norfolk overstrand

causes:
- not enough money to protect all coastline
- cliffs without property are given up
- strong waves, hydraulication&abrasion = wave cut notch
- LSD takes material at foot of cliff away no cliffs fall
- tourism = erosion

effects;

• loose non resistant rock = slumping
• hotel and houses fell into sea
• 1st Janruary 1994, 100m fell into sea
• sea defences need to be rebuild e.g. revetments

Question 24

coastal erosion management example

Answer 24

Norfolk overstrand

hard:
- £1.75m spent
- groynes
- sea wall
- rip rap
- gabions
- revetments

soft:

• cliff regarding
• bore pipes
• tree planting

Question 25

coastal flooding example

Answer 25

The Thames Barrier
completed in 1983
protects 400,000 properties
used 10-15 times a year (increasing)

• water levels rise = more risk of flood
• without it London would have flooded
• 31 January 1953 flood costs millions£ & death
• took 20-30 years to make, largest in world
• defences are not strong enough = to be rebuilt in 2030