Dorset Coast

Question 1

How was Durdle Door-an arch-formed?

Answer 1

1. Formed on hard limestone headland
2. Erosion by waves opened up a crack in it
3. Which became a cave
4. Was widened by erosion and became an arch
5. The arch is gradually being broken down by mechanical, chemical and biological weathering

Question 2

How was Lulworth Cove formed?

Answer 2

1. Small bay formed after a gap was eroded in a band of limestone
2. Behind the limestone is a band of clay
3. The clay is softer so it has been eroded and transported away
4. This formed the bay.

Question 3

How does wind impact the geomorphic processes?

Answer 3

1. The location means that its exposed to prevailing winds from the South West
2. Bring storms to the UK from the Atlantic Ocean
3. Storms bring high energy, destructive waves, increase erosion
4. Hydraulic action and erosion increase and erode the base
5. Makes them unstable and makes mass movement more likely.

Question 4

How does rainfall affect the geomorphic processes?

Answer 4

1. Low amounts of rainfall annually, but can experience very wet winter
2. Soils and rocks become more saturated
3. Makes them heavier and more prone to mass movement

Question 5

How does the geology impact geomorphic processes?

Answer 5

1. Coastline is made of hard and soft rock
2. They eroded at different rates
3. Soft rock like clay are easily eroded by HA & E
4. The harder chalk cliffs are weathered and eroded slower
5. They are exposed as headlands and are vulnerable to solution

Question 6

How do geology,weather and climate interact?

Answer 6

1. Lots of rain makes chalk and limestone vulnerable to carbonation weathering
2. This is because rain water is slightly acidic
3. Prolonged rain causes clay to become heavier, mass movement more likely

Question 7

How does quarrying shaping the landscape?

Answer 7

1. Lots of quarrying as limestone is a valuable building stone
2. Large number of quarrying in the Isle of Portland
3. Quarry exposes large areas of rock
4. Making them vulnerable to chemical weathering and erosion.

Question 8

How does tourism shape the landscape?

Answer 8

1. Attracts large number of tourists
2. Because of coastal footpaths, cliff tops are gradually worn down as people repeatedly walk on them
3. Vegetation is trampled and worn away
4. This can expose the underlying soil and rock to weathering and erosion by wind and rain

Question 9

How do sea walls help erosion?

Answer 9

1. There are concrete walls along most of Swanage beach
2. Reflect waves back to sea, stops erosion
3. But it creates strong backwash, removes sediment, can erode under the wall
4. Prevents cliffs being eroded, no new material to replenish the beach
5. Lower the level of the beach

Question 10

How does Beach Replenishment help erosion?

Answer 10

1. In winter 2005/2006, sand from Poole Harbour was added to upper parts of Swanage beach
2. Creates wider beaches
3. Slow waves and helps protects cliffs from erosion
4. Costs £5 million and needed to be repeated every 20 years.