sea level Flashcards
1
Q
What is the sea level?
A
Average height of the oceans surface between high and low tides
2
Q
What are three short term changes
A
- High and low tides
- Atmospheric air pressure
- Winds push water
3
Q
What are the two types of long term change?
A
Eustatic Change and Isostatic change
4
Q
What is eustatic change?
A
When the sea level itself rises or falls
5
Q
What is isostatic change?
A
When the land rise or falls, relative to the sea
6
Q
What happens to the sea levels during ice ages and glacial periods?
A
Sea levels are lower
7
Q
Sum up eustatic changes: formation/melting
A
- During ice ages, much of the worlds water is ice sheets which means sea level falls
- During the last ice age, there was no north sea, UK joined rest of Europe
- End of global period climate starts to warm up
- Sea levels risen to 120m since last ice age 10000 years ago
- Today antarctic is 4km deep, if it entirely melted sea levels can rise to 50m higher
8
Q
Thermal changes
A
The change in temperature of sea water also contributes to a change in sea levels as water expands in high temperatures
9
Q
Sum up Isostatic changes: post glacial adjustment
A
- Uplift~ removal of weight of ice sheets
- North and west of UK is still rising
- Mantle behaves like fluid
