Sea Level Change Flashcards
What is eustatic sea level change?
This where the sea level changes as a result of a change in the shape of an ocean basin or as a result of a change in the volume of water which causes global effects.
What causes a change in the volume of water in regards to eustatic change?
Thermal expansion.
Melting of icecaps.
When do eustatic changes occur?
During or after an ice age because freezing temperatures suspend the hydrological cycle.
What is frozen water stored as?
Glaciers.
Why do ocean basins change shape?
This is because of tectonic movement.
What will happen as the ocean basin gets bigger?
The sea level will fall.
Does eustatic change have global or local effects?
It has global effects.
What is isostatic change?
This is where the sea level changes because the height of the land changes.
What happens when the height of the land decreases?
The sea level rises.
What happens when the height of the land rises?
The sea level decreases.
Is isostatic change a global or local change?
Local.
When does compression occur?
This occurs during an ice age.
What is compression?
This is where ice builds up on land causing it to sink because of the weight leading to sea level rise.
What happens after an ice age in regards to isostatic sea level change?
Decompression occurs slowly, this is also known as isostatic rebound.
What is isostatic readjustment?
This is the movement of a land as a result of ice moving on or off it.
What is tectonic sea level change?
This is where tectonic plates affect the sea level by either creating mountains or widening the ocean basin. It involves uplift and depression along some plate boundaries.
When do emergent landforms appear?
They appear at the end of an ice age where isostatic readjustment is faster that eustatic rise as the lands height rises faster than that of the sea.
What are signs of emergent features?
Coastal erosional landforms that appear above the current sea level. This is because they developed when the sea was at that level.
What type of a landform is a raised beach?
This is an emergent feature.