Chad Bender, age 8, of East Petersburg, Penn., for his question:

WHAT CAUSES OCEAN WAVES?

The ocean's waters never stop moving. Waves are set into motion by the gravitational pull of the moon and the sun and also by winds and earthquakes.

In an ocean wave, the water moves up and down. There is no forward motion of the water as the wave goes through the water. When the ocean wave reaches land, however, it starts to drag on the bottom. Then the water also moves.

When the moon is directly over any point in the ocean, it pulls the water toward it. The water on the opposite side of the earth alsopiles up. This action results from the spinning of the earth, which tends to make the water fly off the earth's surface. Tides are not high in mid ocean, but may rise six to eight feet near shore. Waves are part of the tide system.