OCEANS. By: Seymour Simon. Tides. The rise and fall of the water in the ocean. High tide and low tide each happen two times a day. Tides are caused by gravity from the sun and the moon. There are different types of tides. Spring Tides.
A tsunami is caused by an underwater earthquake. The earthquake causes a gigantic movement of water. This water moves through the ocean until it hits land.
Click here to see an animation of the waves from the December 2004 tsunami in Asia.