Submergent and emergent landforms

Question 1

How does the climate change naturally

Answer 1

Eliptical orbit every 400,000 years
Solar fluctuations
Volcanic eruptions
Earths tilt changing every 41000 years

Question 2

What happens to sea levels if global temperatures rise

Answer 2

More thermal expansion, more Ice melting means sea levels rise

Question 3

What is isostatic change

Answer 3

Isostatic change is localised changes in sea level this could include the rebounding of ground after ice has melted off the ground. This causes sea level to fall or Ice being formed on the ground and weighing it down causing the sea level to rise

Question 4

What is eustatic change

Answer 4

Eustatic change is when there are global changes in sea level. This could be change is sea basin sea ice melting or freezing or thermal expansion

Question 5

How much will global temperatures rise by the end of the century

Answer 5

2 degrees

Question 6

how are emergent landforms created

Answer 6

Landforms created when the sea levels were the highest and now the sea level has fell.

Question 7

Raised beaches marine terraces and abandoned cliffs

Answer 7

On the southern tip of portland near weymouth there is a distinct rasied beach 15 metres above present day sea level formed 125000 years ago. Portland limestone here was eroded by hydraulic action erosion rates as high as 1 metre per year back then. Still being influenced by tree root weathering as well as carbonation. Due to further warming of the globe

Question 8

How much does a 1 degree rise in global temperatures contribute to sea level rise

Answer 8

Rise of 2 metres

Question 9

How is a ria formed

Answer 9

When sea levels rise and flood an unglaciated valley eg.poole harbour depth 48 cm near river mouth gets shallower as going inshore

Question 10

How is a fjord formed

Answer 10

When sea levels rise and flood a previously glaciated valley. These often have deep valleys and have deep water parts Eg Lysefjord Norway depth 13 metres at sea then 400 metres inland

Question 11

How are shingle beaches formed

Answer 11

When sea levels fall and “new” land emerges sediment accumulates on this surface creating a beach one example is Chesil beach connecting to the island of Portland beach now contains 100 million tonnes of sediment