Patty Davis, of Wichita, Kan,., for her question:

Where is the Mindanao Trench?

The floors of the oceans are as bumpy as the dry land. There are hills and high mountain ranges, cliffs and deep canyons,. all hidden beneath the salty waves. The depth of the canyons is measured from the surface of the sea. Long, deep canyons are called ocean trenches. In these deep ditches there are often deeper pits. The pits which are deeper than 18,000 feet are called ocean deeps,

The Mindanao Trench lies east of the Philippines. It is a long ditch in the ocean floor more than six and a half miles below the surface of the sea. If Mount Everest were set in the bottom of the Mindanao Trench, its snowy crown would be a mile below the surface of the Pacific. New information about the ocean floor was gathered during the International Geophysical Year. Next Wednesday, Andy will have more to tell you about the deep trenches in the ocean floor.