Wednesday, February 8, 2012

Project: Icebergs and Sea Level

Do you think melting icebergs raise the sea level?  Do this experiment and find out.
You will need:  a glass bowl, water, ruler, ice cubes
1.  Pour water into the bowl until it is about half full.  Use the ruler to measure the height of the water.
2.  Add the ice cubes.  Measure the water level again.  How much did it rise?  Each ice cube is like a tiny iceberg.
3.  Set the bowl in a warm place until all the ice is melted.  Measure the water level again.  What happened?  (Remember that water increases in volume when it freezes.)

   When a large piece of ice breaks off the edge of a glacier and falls into the ocean, a process called calving, the chunks of floating ice are called icebergs.  In the northern hemisphere, most icebergs break off glaciers in Greenland into the North Atlantic.  Icebergs also form off the coast of Alaska in the Pacific.  In the southern hemisphere, an iceberg the size of Rhode Island recently broke off from Antarctica.  Icebergs drift in the ocen currents until they melt.
   In recent years, the average air temperature of Earth has been going up, and the polar ice sheets have begun to melt.  If melting ice causes sea level to go up by even a few feet, the chance of flooding for coastal cities could increase.  Which cities in the United States could be affected by a sea level rise?

   Read more about icebergs and find other projects in The Geography Book:  Activities for Exploring, Mapping, and Enjoying Your World.

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