Role Of Sea Level Change Flashcards
1
Q
What is isostatic change?
A
- The land rises or falls relative the sea
- localised change
2
Q
Process of isostatic sea level change?
A
- often a result of isostatic subsidence = ice thickness increases so the land is lowered
- tectonic activity (earthquakes + volcanic eruption) may cause land subsidence, therefore causing isostatic sea level chnage
3
Q
What is eustatic change?
A
- refers to global change in sea level
4
Q
Process of eustatic sea level change
A
- temperatures rise, ice melts through thermal expansion = sea level rises
- temperature decreases, glaciers + ice sheets advance = sea levels fall
5
Q
Sequence of sea level change
A
- Temperature decreases, glaciers + ice sheets advance = sea levels fall eustatically
- Ice thickness increases + land is lowered isostatically
- Temperature rise, ice melts + sea levels rise eustaticslly
- Continued melting releases pressure on the land + the land rises isostatically
6
Q
What are emerged coastlines?
A
- where the land has been raised in relation to the coastline
- landforms such as arches, stacks + stumps may be preserved
7
Q
Features of emerged coastlines
A
- raised beaches
- coastal plains
- relict cliffs
- raised mudflats
8
Q
What are submerged coastlines?
A
- occur when sea level rises or coastline sinks in relation to the sea
9
Q
Features of submerged platforms
A
- rias = flooded river valleys
- fjords = flooded glacial valleys
- Dalmatian coats = valleys parallel to the coast flooded creating a series of narrow, long islands
