Earthquake Terms
- Convection Current: very slow movement of rock within Earth's mantle caused by heating and cooling.
- Epicenter: the point on Earth's surface directly above the focus of an earthquake.
- Fault: a crack in rock or soil along which there has been movement caused by stress.
- Focus: the point inside Earth which is the source of the earthquake.
- Lithosphere: outer solid portion of Earth including the crust and uppermost mantle.
- Mantle: the zone inside Earth between the solid outer crust and the inner core.
- Seismograph: a device for measuring and recording vibrations from earthquakes.
- Tsunamis: large ocean waves generated by major earthquakes beneath the ocean floor. Tsunamis caused by nearby earthquakes may reach the coast within minutes. Tsunamis may also be generated by very large earthquakes far away in other areas of the Pacific Ocean. Waves caused by these earthquakes will reach California several hours after the earthquake.