Sea level changes Flashcards
How much are the sea levels forecast to rise by?
2mm a year and this is set to rise to 4mm or 5mm a year by 2100.
What will a rise in sea levels cause?
An increase in the frequency and severity of flooding in low lying coastal areas.
What is Eustatic sea level change?
It is a change in the volume of water in the sea.
What are the main causes of eustatic change?
Tectonic movements of the earths crust which alter the shape& volume of ocean basins
Change in climate- an increase in temperature causes an increase in sea levels as water expands.
What is isostatic sea level change?
It is the vertical movements of land relative to the sea.
What are the main causes of isostatic change?
Tectonic uplift or depression which occurs at plate boundaries.
Compression or decompression of the earths crust due to a change in ice sheets. This can cause glacial rebound
Subsidence of land due to shrinkage after abstraction of ground water.
What are the impacts of sea level rise?
More frequent or more severe coastal flooding, submergence of low lying island, changes in the coastline.
Name 3 landforms of submergence?
Rias, fjords, dalmatian coastline
How are rias formed?
They are formed where river valleys are partially submerged. Eg Milford Haven in South Wales. Rias have a gentle long and cross profile. They’re wide and deep at their mouth, they become narrower and shallower further inland.
How are Fjords formed?
They are drowned glacial valleys. They are relatively straight and narrow with straight sides. They have a shallow mouth caused by a raised bit off ground formed by deposition of material by the glacier. Further inland they’re very deep.
How are Dalmatian coastlines formed?
When valleys are flooded islands are left parallel to the coastline.
Name a landform of emergence?
Raised beaches
How are raised beaches formed?
They are formed when the fall in sea level exposes wave-cut platforms and their beaches. Over time , beach sediment becomes vegetated and develops into soil.
How are Relict cliffs formed?
They are the cliffs above the raised beaches which are no longer eroded overtime. They are slowly covered by vegetation.
