people died from the tsunami than the quake.

of the trough.

• body wave: Type of seismic wave that travels through the body of a planet; body waves include primary waves and secondary waves.

• crest: Highest point of a wave.

• Love wave: Surface wave that has a side-to-side motion, much like a slithering snake.

• primary wave (P-wave): Fastest type of body wave, capable of traveling through solids, liquids, and gases.

• Rayleigh wave: Surface wave that has a rolling motion.

• secondary wave (S-wave): Slower moving, transverse body wave that can only travel through solids.

• surface wave: Seismic wave that travels around the ground surface; the two types are Love and Rayleigh waves.

• trough: Lowest point of a wave.

• wavelength: Horizontal distance between two waves, as measured from crest to crest or trough to trough.

• tsunami: Enormous wave generated by vertical movement of the ocean floor during an underwater earthquake; tsunamis can also be caused by volcanic eruptions, landslides, or meteorite impacts. A deadly set of waves can rise high on a beach and travel far inland.

• dip: Angle of a fault relative to horizontal.

• dip-slip fault: Fault in which the dip of the fault plane is inclined relative to the horizontal.

• fault: Fracture along which one side has moved relative to the other.

• fault zone: Group of faults.

• joint: Break in rock along which there is no movement.

• normal fault: Dip-slip fault in which the hanging wall drops down relative to the footwall.

• reverse fault: Dip-slip fault in which the hanging wall pushes up relative to the footwall.

• slip: Distance rocks move along a fault.

• strike-slip fault: Fault in which the dip of the fault plane is vertical.

• thrust fault: Reverse fault in which the dip of the fault plane is nearly horizontal