Isostatic and Eustatic change

Question 1

eustatic change definition

Answer 1

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

Question 2

isostatic change definition

Answer 2

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

Question 3

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

Answer 3

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

Question 4

how can tectonics affect sea level rise

Answer 4

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

Question 5

why is there a eustatic fall in glaciation periods

Answer 5

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

Question 6

isostatic change in glaciation periods

Answer 6

ice forces land mass down in glaciation periods

Question 7

when does isostatic rebound occur

Answer 7

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

Question 8

what landforms can form during the prolonged rebound period

Answer 8

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