Jim Guerre, age 9, of East Lansing, Michigan, for his question:

How deep is the ocean?

Along the beaches, the ocean water is only deep enough to wash your toes. It gets deeper out to sea, as the floor of the sea slopes gently down. Miles from the shore, the sea bed takes a sudden dip, straight down the sides of some very steep cliffs. This is the wall of the deep ocean basin. The bottom of the basin may be two miles or more than three miles below the waves. The depth depends upon which ocean it is.

You might expect the floor of the sea to be flat and level. Actually it has more ups and downs than the land. One deep sea valley dips down more than six miles. If all the bumps were smoothed out, the Pacific Ocean would be about three miles deep. This is called the average depth. The average depth of the Atlantic is about 2 1/2 miles. And if all the oceans in the world were smoothed to the same level, their average depth would be about 2 1/3 miles.