Lesson 8-What are the erosional landforms at the coast?

Question 1

Concordant coastlines

Answer 1

• Lines of rock parallel with coastline; uniform erosion. Less dramatic, fewer features as the same band of rock will follow the shape of the coastline> Culworth Cove

Question 2

Discordant coastline

Answer 2

• Lines of rock perpandicular to coastlines, irregular erosion; formation of headlands and bays.

Question 3

How are headlands eroded?

Answer 3

• Wave refraction
  -Headlands have a shallow depth around them that make waves slow down due to friction with the sea bed
  -wave energy concentrates on the headland

Question 4

Erosional landforms?

Answer 4

• Blowhole
• Geos
• Stacks

Question 5

Erosional landforms-Blowhole

Answer 5

• Hole in the tpop of a cave created whren a sea cove grows inland and upwards through vertical erosion
• As air flows into the cove air is expelled through the pipe like joing casusing a blast of air
  -e.g Portland in Dorset

Question 6

Erosional landforms-Geos

Answer 6

• Is an inlet, a gully or a cliff
• Created by the erosion of cliffs along faults and bedding planes in the rock
  -geos are common on the coastline of the Scotland and Orkney Islands in Norway

Question 7

Erosional landforms-Stacks

Answer 7

1) Geological weakness
2) Formation of sea cove by erosion
3) Enlargementof cove to form and an arch to form a stack
4) Collapses to form a stack
5) Removal of stack to create a stump

Question 8

What are cliffs?

Answer 8

• Landforms shaped through a combination of erosion, weathering and mass movement

Question 9

Factors affecting cliffs

Answer 9

• Weathering
• Erosion from waves
• Mass movement

Question 10

Factors affecting cliffs-Weathering

Answer 10

• Biological weathering attacks the cliff top, can also weaken them

Question 11

Factors affecting cliffs-Erosion from waves

Answer 11

• Erosion aqttacks the foot, causing a wave-cut notch at the bottom particularly where waves break in a similar pattern
  -the tidal range

Question 12

Factors affecting cliffs-Mass movement

Answer 12

• Affects the shape of the cliff as more mass movement will create a steeper gradient

Question 13

Factors affecting cliff erosion?

Answer 13

• Geology
• No beach-
• Energy of environment
• Angle of rock layers- if vertical then its more steep

Question 14

Lithology of the coast

Answer 14

• Strata
• Bedding planes
• Joints
• Folds
• Faults
• Dip

Question 15

Strata

Answer 15

• Layers of rock

Question 16

Bedding planes

Answer 16

Horizontal natural breaks in the strata- caused by gaps in time changing periods of rock formation

Question 17

Joints

Answer 17

Vertical fractures caused either by contraction as sediments dry out or by earth movements causing uplift

Question 18

Faults

Answer 18

• Formed when the stress or pressure to which a rock is subjected to exceeds its internal strength
  -The faults then slip or move along fault planes

Question 19

Dip

Answer 19

• Refers to the angle at which rock strata lie (horizontally, vertically, dipping towards the sea or dipping inland)

Question 20

What are wave cut platforms?

Answer 20

• Marine erosion between the high tide and low tide mark by abrasion and hydraulic action forms a wave-cut notch along the length of the cliff base with a maximum width of 0.5km

-usually occurs when there is a low tidal range as it constantly eroding the same area and when waves break at the foot of the cliff

Question 21

Wave cut platforms a positive or negative feedback loop?

Answer 21

• Negative feedback loop as a wave will break earlier and its energy will be dissipated before it reaches the cliff, thus reducing the rate of erosion, limiting the further growth of the platform
  -at flamborough head there are wave-cut platforms

Question 22

Why is erosion the more dominant process rather than deposition at the Holderness ?

Answer 22

Due to geology>boulder clay
Due to weather>weathering leads to more mass movement
Due to waves>quite a large fetch from the North Sea