posted on Aug, 27 2009 @ 09:32 PM
reply to post by Maddogkull
The amount of water existing as ice on the land masses will have some effect on ocean levels. During an ice age, when glaciers form in large
quantities over the land, there is less water in the oceans and therefore a lower sea level. During warmer periods, there is less ice existing as
land-based glaciers and therefore the sea level is higher.
Most of the large differences, however, can be attributed to tectonic activity. That is, massive plates that make up the earth's surface can move
slowly against each other. Sometimes they are thrust upward from the pressure of two advancing plates; sometimes one plate is buried beneath another.
Differences in pressures under the crust due to this movement can also cause areas of land to rise and fall without being on the junction of two
I hope that cleared things up for you.