Martha Hansen, age 11, of Visalia California, or her question:

How can an earthquake make a tidal wave?

Shake a basin of water and watch what happens to the surface. The water heaves and tosses, breaks into raves and splashes all over. The ocean is really a mammoth basin of water. The seas rest on vast floors of solid rock. The surface is ruffled by the winds and by the ebbs and flows in the tides, These surface upsets do not disturb the deep ocean waters very much.

But an earthquake shakes the very floor of the ocean. The deep, still waters below are tossed this way and that. This deep water in turn upsets the surface waters. Instead of waves, the sea piles up into great mountains of water.

This is the ocean upheavel which very often follows an earthquake. These huge tidal waves can travel much further than the land area over which the earthquake is felt. They have been known to travel clear across the Pacific Ocean.