| A | B |
|---|
| earthquake | sudden movement or shaking of the Earth's crust. |
| volcano | place, usually a hill or mountain, through which hot liquid rock from deep inside the Earth bursts. |
| tsunami | giant sea wave caused by an earthquake. |
| vent | opening of a volcano from which lava erupts. |
| seismograph | instrument that measures and decets seismic waves. |
| focus | point beneath the surface of the Earth where the rocks break and move during an earthquake. |
| epicenter | area on the Earth's surface directly above the focus. |
| crater | funnel-shaped pit at the top of a volcanic cone. |
| lava | molten rock that has reached the Earth's surface. |
| magma | molten rock that is still underground. |
| seismologist | scientist who studies earthquakes. |
| dome | mountain or large hill formed by magma pushing up on the rock layers above it. |
| primary wave (P-wave) | a push-pull seismic wave, which can travel through solids, liquids and gasses; P-waves are the fastest type. |
| secondary wave (S-wave) | a side-to-side wave, which can travel through solids but not through liquids or gasses; S-waves are the second fastest wave. |
| surface wave (L-wave) | an up-and-down wave, L-waves are the slowest-moving seismic wave, but result in the most damage. |
| cinder cone | a volcano made mostly of cinders and other rock particles that have been blown into the air. |
| shield volcano | a volcano composed/created from quiet lava flows. Gently sloping, dome shaped volcano. (i.e. Mauna Loa in Hawaii.) |
| composite volcano | volcano built up of alternating layers of rock particles and lava. Begins with a violent eruption followed by quiet eruptions which produce lava flows which cover the particles. |
| caldera | a very large hole at the top of the volcano created by the collapse of the crater's walls. |
| Richter scale | a scale which measures the energy an earthquake releases by assigning the earthquake a number from 1 to 10. The more energy the higher the number, the stronger and more damaging the earthquake is. |
| Reverse or Thrust fault | A fault caused by the compression of the Earth. |
| isostasy | A balancing of the downward force of the crust and the upward force of the mantle. |
| Shearing | a stress that pulls the Earth's crust in opposite horizontal directions. |
| fault | a break in the rock |
| fold | a bend in the rocks |
| normal fault | a fault created by tension stress |
| lateral or strike-slip fault | a fault created by shearing stress |
| tension | a stress that pulls the Earth's crust apart |
| compression | a stress that pushes the Earth's crust together |
| dome | Mountain created by a mass of molten magma pushing up on the crust |
