Sea level change Flashcards
How is sea level change measured?
Sea level change is measured relative to the land
What are the two ways sea level can change?
Eustatic sea-level change and Isostatic sea-level change
What is Eustatic sea-level change?
The sea rises or falls relative to the land, It is always global
What is Isostatic sea-level change?
The land rises or falls relative to the sea, it is always local
What type of sea-level change took place in the last glacial period?
More water was stored on land as ice so less water in the oceans leading to rapid global fall of the ocean, meaning its eustatic sea-level fall, however there was also isostatic sea-level rise as the land lowered due to the weight of the ice
What is a ria?
Where sea-level rise has flooded a river valley
Where is an example of a ria?
The Fal Estuary in Cornwall
What is a fjord?
Where sea level rise has flooded a glacial valley
Where is an example of a fjord?
Milford Sound in New Zealand
What causes isostatic sea-level change?
It is due to isostatic subsidence and isostatic rebound
Where is an example of an emergent landscape due to isostatic rebound?
Pladda, an island off the Isle of Arran
Where is an example of fossil cliffs and a raised beach?
Seljalandsfoss in Iceland
How is the UK showing the see-saw effect?
Scotland is raising by 2mm/y showing isostatic rebound and Cornwall is lowering by 1.4mm/y showing isostatic subsidence and no change in the middle
Where is an example of tectonic isostatic sea level change?
The New Zealand EQ of 2016 raised 120km of coastline by 1-8 metres putting previously at risk infrastructure out of harms way from sea erosion
What is thermal expansion?
Global warming is resulting in warmer oceans, meaning sea water expands resulting in a greater volume
