Question | Answer |
Stress | a force that acts on rock to change its shape or volume |
Tension | a stress force that pulls on the crust |
Compression | a stress force that squeezes rock until it folds or breaks |
Shearing | stress that pushes rock in two opposite directions |
Normal Fault | the fault is at an angle, the hanging wall is pushed up the footwall |
Hanging Wall | the block of rock that lies above the angle of the fault |
Footwall | the block of rock that lies below the angle of the fault |
Reverse Fault | the fault is at an angle, the hanging wall is pushed up the footwall |
Strike-Slip Fault | the rocks on either side of the fault slip past each other sideways |
Anticline | a fold in rock that bends upward into an arch |
Syncline | a fold in rock that bends downward to form a valley |
Plateau | a large area of flat land elevated high above sea level |
Earthquake | the shaking and trembling that results from the movement of rock beneath earth's surface |
Focus | the area beneath Earth's surface where rock under stress breaks, triggering an earthquake |
Epicenter | the point on the surface directly above the focus |
P wave | primary waves, seismic wave that compress and expand the ground |
S wave | secondary waves, seismic wave that vibrate from side to side as well as up and down |
Surface wave | seismic wave that forms when P and S waves reach the surface |
Richter Scale | a rating of an earthquake's magnitude based on the size of the earthquake's seismic waves |
Seismograph | an instrument that records and measures seismic waves |