sea level changes and landforms Flashcards
what is eustatic?
global change
what is isostatic
local change
what are the 3 types of sea level change?
eustatic
isostatic
tectonic
what are eustatic changes a result of?
global sea level changes
what happens during eustatic sea level fall?
during ice age there is less water in the ocean as much precipitation falls as snow and joins the ice on the land, therefore sea levels fall
what happens during eustatic sea level rise?
when ice melts volume of water in ocean increases so sea levels rise
global warming is increasing sea levels due to thermal expansion of the oceans and the melting of freshwater ice sheets
isostatic changes are a result of?
local sea level changes
which occurs faster isostaic change or eustatic change?
eustatic
what are isostatic changes a result of?
weight of the ice
when large ice sheets cover the land it weighs down the land and makes it sink so sea levels rise
when the ice melts the land rises as the weight has been removed this is isostatic reajustment - the land begins to rise and sea levels fall
what can tectonic activity result in?
eustatic sea level change over a much larger time scale by decreasing and increasing the size of ocean basins meaning there is a larger or smaller area to contain the given volume of the ocean
changes is base level affect coastal landscapes in what 2 ways?
a fall in base level causes the existing landform to be raised above current sea level and be subject to sub areal weathering
a rise in sea level submerges existing landforms with new ones forming at a higher sea level