Tsunamis: large ocean waves that rush over land
Context Clues: "set of ocean waves" and "rush over land"
Earthquake: a sudden shaking of the ground caused by movement of rocks
Context Clues: "undersea earthquake" and "causes the ocean floor to move and shake"
Extend: to reach a certain point or distance
Context Clues: "They extend, or reach, deep down into the ocean."
Shore: the land along the edge of an ocean, lake, or river
Context Clues: "The waves head for shore" and "the land along the ocean."
Damage: harm or injury to something or someone
Context Clues: "Tsunamis cause lots of damage and harm."