Sea Level Change Flashcards
Eustatic Sea Level Change
Caused by a change in volume of water in the sea, or change in shape of the ocean basins.
The effects are always global and the main causes are:
Changes in climate -
An increase in temperature causes melting of the ice sheets, which increases sea level.
A decrease in temperature causes more precipitation to fall as snow. This increases the volume of water stored in glaciers and so reduces the volume of the sea and so decreases water.
Tectonic Movements -
Tectonic movements of the earth’s that alter the shape of ocean basins. E.g sea floor spreading increases the volume of the basin.
Isostatic Sea Level Change
Isostatic sea level change is caused by the vertical movements of the land relative to the sea.
Any downward movement of the land causes sea level to rise locally, while uplift of land causes sea level to fall.
The effects are always local and the main causes are:
Uplift or depression
Tectonic processes
Subsidence of land due to shrinking after the abstraction of groundwater
