Sea level change

Question 1

What are the ways sea level changes?

Answer 1

1. Eustatic change
2. Isostatic change
3. Tectonic change

Question 2

What is eustatic change?

Answer 2

This is when the amount of water in the oceans changes on a global scale.

Question 3

What is isostatic change?

Answer 3

Height of the land changes due to increased weight/ pressure so the sea level changes on a local scale.
Occurs during an ice age.

Question 4

What is tectonic change?

Answer 4

Height of the land changes due to changes by tectonic plates, so sea level changes on a local scale.

Question 5

What is a Fjord?

Answer 5

A flooded glacial valley which results in a rise in sea level change at the end of an ice age.

Songe fjord, Norway

Question 6

How is a Fjord formed?

Answer 6

Continual inputs of snow and ice provides the energy to move the glacier and starts the process of erosion, deepens and widens v-shaped valley. At the end of the ice age water floods the now u-shaped valley.

Question 7

What is a Ria?

Answer 7

Its a drowned river valley which is caused by sea level rise.

Kingsbridge estuary, Devon

Question 8

How is a Ria formed?

Answer 8

Rising sea level causes the lower part of the river valley to be flooded where the land is low lying.

Question 9

What is a Dalmatian coast?

Answer 9

A dalmatian coast occurs when an area of higher land runs parallel to the coast, this is then flooded by sea level rise so becomes islands.

Croatian coastline, Adriatic

Question 10

What is a raised beach/ relic cliffs?

Answer 10

Formed when the sea level falls which causes them to be isolated from the sea.

East Prawle, Devon

Question 11

How much are sea levels predicted to rise?

Answer 11

From 1-3m by 2100, although many different scientists and experts have different opinions on this figure.

Question 12

Typical sea level changes during an ice age:

Answer 12

1. Colder climate means water is stored as snow and ice so less in the sea. Sea level drops, eustatic change.
2. Weight of the snow and ice on land causes it to sink. Sea level rises, isostatic change.
3. Climate increases as ice age ends, stored water returns to ocean. Sea levels rise, eustatic change and submerging landforms created.
4. As weight is removed on land it slowly rebounds. Sea level falls, isostatic re-adjustment and emergent landforms formed.