Unit 1- Coastline

Question 1

How is a wave formed?

Answer 1

• Circular orbit
• Friction from rising seabed cuases eliptical orbit
• Top of wave breaks over

Question 2

What is a constructive wave?

Answer 2

-Less energy
-Larger swash —-> deposits material
-Low frequency ( >10 per min)
-Large wavelength + short

Question 3

Where are constructive waves found?

Answer 3

-Bays
-Lower depth
-More friction from ocean floor

Question 4

What is a destructive wave?

Answer 4

-High energy
-Larger backwash —->erodes
-High frequency (10-14 per min)
-Tall but short wavelength

Question 5

How are destructive waves formed?

Answer 5

• Long fetches (distance)
• Storms
• Deep sea (headlands)

Question 6

x3

Weathering?

Answer 6

• Mechanical
• Chemcial
• Biological

Question 7

What is mechanicle weathering + example?

Answer 7

-Physical erosion (by abiotic things)
-Freeze-thaw:
Day temp warmer, water gets in rock crack
Night temp colder, water freezes + expands
—–> crack increased + repeat on larger scale

Question 8

What is chemical weathering + example?

Answer 8

• Erosion by chemical changes
  -Carbonation:
  Acid rain erodes limestone

Question 9

What is biological weathering + example?

Answer 9

• Living organsims erode
  -Plants grow and expand in cracks of rock

Question 10

What is longshore drift?

Answer 10

• Prevailing wind at an angle to coast
• Waves income at an engle
• Waves deposite material and remove material at that incoming angle
• Backwash is 90 degrees
  -Cuases sediment movement in a zig zag motion

Cuases mass movement of sedimentation

Question 11

What are the two types of coastline?

Answer 11

-Concordant
-Disconcordant

Question 12

What is concordant coastline?

Answer 12

• Layers of hard and soft rock parallel to coast
  -coast against one type of rock

Question 13

What is disconcordant coastline?

Answer 13

• Layers of hard and soft rock perpendicular to coast
  -coast against two types of rock

Question 14

How is a bay and headlands formed?

Answer 14

• Normally disconcordant coastline
• water erodes soft rock, whilst hard rock on either side remain large

Question 15

Famouse bay on a concordant coastline?

where is it

Answer 15

Lulwoth cove
dorset

Question 16

How was lulworth cove formed?

Answer 16

-Water eroded narrow part of hard rock
- Quickly eroded soft rocks behind it
- Cuased almost circular bay

Question 17

How are caves formed?

Answer 17

Hydraulic action and abrasion eroded a dent in rock

Question 18

How are arches formed?

Answer 18

Cave in headland eroded all the way through

Question 19

How are stacks formed?

Answer 19

• Arch rock collapses without support

Question 20

How are stumps formed?

Answer 20

• Stack rock weathered down

Question 21

Famouse arch?

where

Answer 21

-Durdle door
-Dorset

Question 22

How is a wavecutt platoform formed?

Answer 22

• Water erodes rock at sea level
• Rock above collapses
• Land retreats

bedding planes how soft and hard rock layered in cliff

Question 23

What is a beach

Answer 23

Buffer between land and sea

Question 24

How is a spit formed?

Answer 24

-Narrow land of sand and shingle
-Deposited material behind headland (estuary)
-Secondary wind cuases light curve

-Longshore drift continues as coastline changes direction
-Shallow cuases lots of deposition

Question 25

What is a bar ?

Answer 25

- Bar connects too headlands - Cutts of a bay from sea - Deposited material

Question 26

What is a tombolo?

Answer 26

Spit connecting mainland and island

Question 27

How is a salt marsh formed?

Answer 27

- Sheltered area (behind spit or in estuary) - Vegitation colonises mudflats - Saline - Roots as anchors

Question 28

How are sand dunes formed?

Answer 28

Sand blown by wind is trapped