| A | B |
|---|
| secondary wave | seismic waves that move matter from side to side |
| epicenter | the earth's surface directly above the focus |
| surface wave | seismic waves that cause a rolling motion in the rock and soil |
| reverse fault | when rocks above the fault surface are pushed up over the rocks on the other side |
| seismograph | an instrument that measures and records seismic waves |
| normal fault | when rocks above the fault surface move down |
| strike-slip fault | when rocks on either side of the fault slice past each other |
| earthquake | the shaking of the ground caused by movement of rocks |
| shadow zone | a region where seismic waves are not received |
| seismic wave | a vibration produced by an earthquake |
| focus | the true location of an earthquake |
| primary wave | seismic waves that cause matter to stretch and compress |
| composite cone | a mountain made of layers of tephra and lava |
| volcano | an opening in the Earth's crust where magma comes out |
| shield cone | a volcanic mountain made of sheets of lava flow with a broad base and gently sloping sides |
| cinder cone | a volcanic mountain made of tephra |
| tephra | pieces of ash, cinder, and rock from a volcano |
| tsunami | a huge wave caused by underwater Earth movement |
| Richter scale | a numerical description of the size of the seismic waves of an earthquake |
