Homework Help.. Geology?

Question

Hi guys!! So I have this question for my geology class that I'm sort of stumped on... if anyone can help me I'd be so grateful! Here it goes.. "If all the glaciers and ice sheets on earth melted, how high would the sea level rise?" I have the old verson of the textbook which doesn't have the volume of all glaciers and ice sheets on earth. I know I have to take the surface area of the earth and somehow add that volume to it.. but how would I distribute that to the earth's surface area? If you can help me answer it, can you also provide the steps in which you got the answer? Thanks so much!!

Answer 1

According to the following data from the USGS, the total sea level rise from melting of all glaciers and ice caps would result in a total sea level rise of 80.5 meters.  From the Water Encyclopedia site, it is 75 meters.  This gives you an approximation, so you know whether your result is in the ball park.  

This wouldn't spread over the entire surface of the Earth, but would flood some areas around the edges of the continents and some islands.  

However, from the question, you only need the sea level rise, not spread over the entire surface area of the Earth.  

Hopefully, they don't expect you to calculate the % difference in ice volume melted to water volume.

When they do these calculations, they only include the surface area of the seas, not the land.  So you would need the volume of all the ice now contained in ice caps and glaciers (given below).  So, if you have the total surface area of the seas and the total volume of water released, you would only have to calculate the depth of that volume of water distributed over the total sea surface area.  I am thinking that if you have volume in cubic meters of water to spread over area in  square meters of sea surface, and are looking for depth in meters, you wouldn't need to worry about the shape of the area.  It seems that you would use:

    Volume cubic meters / Area sq meters = Depth meters

"Most of the current global land ice mass is located in the Antarctic and Greenland ice sheets (table 1). Complete melting of these ice sheets could lead to a sea-level rise of about 80 meters, whereas melting of all other glaciers could lead to a sea-level rise of only one-half meter."

"Glaciers and ice sheets both affect and are affected by changes in Earth's climate. They are frozen fresh-water reservoirs that change volume in response to changes in temperature and snowfall. Were the ice sheets in Greenland and Antarctica to melt entirely, global sea level would rise about 75 meters (250 feet).

The majority of the ice, 29 × 106 cubic kilometers (approximately 7 million cubic miles), is in Antarctica. The Greenland Ice Sheet holds 2.95 × 106 cubic kilometers (706,000 cubic miles) of ice, whereas glaciers and ice caps amount to about 0.18 × 106 cubic kilometers (43,000 cubic miles)."