Isostatic and Eustatic change Flashcards Preview

Geography-- Coasts > Isostatic and Eustatic change > Flashcards

Flashcards in Isostatic and Eustatic change Deck (8)
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1
Q

eustatic change definition

A

a GLOBAL change in sea level resulting from a fall or rise in the level of the sea itself

2
Q

isostatic change definition

A

local changes in sea level resulting from the land rising and falling relative to the sea

3
Q

sea levels rise for two major factors … (explain them)

A
thermal expansion (where the volume of water increases as it gets warmer)
land ice melt (melting of glaciers and ice sheets)
4
Q

how can tectonics affect sea level rise

A

set amount of water on earth but depth depends on the volume it has to fill. larger oceans= lower levels. smaller= sea levels will be higher. all due to tectonic movement- opening and closing of the ocean basin.
also tsunamis- plate flips up- slightly alters the volume of water

5
Q

why is there a eustatic fall in glaciation periods

A

global temps=cool- so ice forms on land in form of glaciers and ice sheets.
accumulation on land means less in the sea- so there is a fall in sea level

6
Q

isostatic change in glaciation periods

A

ice forces land mass down in glaciation periods

7
Q

when does isostatic rebound occur

A

once the ice is fully removed (after glaciation period) isostatic rebound occurs

8
Q

what landforms can form during the prolonged rebound period

A

emergent features eg raised beaches which now sit below sea level
rising sea levels flood some coastlines and create submergent features - form fjords and rias