Coasts Revision Flashcards
Define isostatic sea level change
When land rises and falls relative to the sea level. It is caused by the weight ice sheets put upon the land, creating ISOSTATIC SUBSIDENCE
When the ice melts, the land springs back causing areas not covered by ice to sink and areas previously covered to rise, this is known as ISOSTATIC RECOVERY
Define Eustatic sea level change
When sea levels rise and fall
This happens over a much shorter time period - an ice age
When water freezes forming ice, water doesn’t return to the sea causing a fall in sea level
When ice melts more water returns to the sea causing a rise in sea level
Thermal expansion also causes sea levels to rise as the atmosphere becomes warmer, the oceans absorb more, heat, expanding thus resulting in a rise of sea level
What is an emergent coastline and name the two types
Caused by isostatic change
- they are formed where land rises above sea level
Two types:
Raised beaches
Relic cliffs
What are submergent coastlines, name the three types
Eustatic change leads to submerge by coastlines
- they are formed where water level rises and floods land
3 types:
Rias = submerged river valleys
Dalmatian coasts = long narrow strips of islands running parallel to the coast
Fjords = long narrow deep body of water that reaches far inland
