Column 1
Stress that pushes masses of rock in opposite directions, in a sideways movement
Shearing
A type of seismic wave that moves the ground up and down or side to side
Secondary (S) wave
The measure of an earthquake's strength based on seismic waves and movement along faults
Magnitude
A type of fault where the hanging wall slides upward, caused by compression in the crust
Reverse fault
Stress that squeezes rock until it folds or breaks
Compression
A device that records ground movements caused by seismic waves as they move through Earth
Seismograph
A force that acts on rock to change its shape or volume
Stress
The block of rock that forms the upper half of a fault
Hanging wall
A type of seismic wave that forms when P waves and S waves reach Earth's surface
Surface waves
The point on Earth's surface directly above an earthquake's focus
Epicenter
The shaking that results from the movement of rock beneath Earth's surface
Earthquake
A scale that rates earthquakes according to their intensity and how much damage they cause at a particular place
Mercalli scale
The point BENEATH Earth's surface where rock breaks under stress and causes an earthquake
Focus
A large area of flat land elevated high above sea level
Plateau
A block of rock that forms the lower half of a fault
Foot wall
The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud
Liquefaction
Stress that stretches rock so that it becomes thinner in the middle
Tension
A type of fault where the hanging wall slides downward. Caused by tension in the crust
Normal fault
A type of seismic wave that compresses and expands the ground
Primary (P) wave
The record of an earthquake's seismic waves produced by a seismograph
Seismogram
Type of fault in which rocks on either side move past each other sideways with little up or down motion
Strike slip fault
A scale that rates an earthquake's magnitude based on the size of its seismic waves
Richter scale
A large wave produced by an earthquake on the ocean floor
Tsunami
A scale that rates earthquakes by estimating the total energy released by an earthquake
Moment magnitude scale
An earthquake that occurs after a larger earthquake in the same area
Aftershock