| A | B |
|---|
| magma | the molten or partially molten rock material containing trapped gases produced under the Earth's surface |
| lava | magma that flows onto Earth's surface; the rock that forms when lava cools and solidifies |
| focus | the location within Earth along a fault at which the first motion of an earthquake occurs |
| epicenter | the point on Earth's surface directly above an earthquake's starting point, or focus |
| deformation | the bending, tilting, and breaking of Earth's crust; the change in the shape of rock in response to stress |
| folding | the bending of rock layers due to stress |
| fault | a break in a body of rock along whihc one block moves relative to another |
| volcano | a vent of fissure in Earth's surface through which magma and gases are expelled |
| hot spot | a volcanically active area of Earth's surface, commonly far from a tectonic plate boundary |
| earthquake | a movement or trembling of the ground that is caused by a sudden release of energy when rocks along a fault move |
| elastic rebound | the sudden return of elastically deformed rock to its undeformed shape |
| tectonic plate boundary | the edge between two or more plates classified as divergent, convergent, or transform by the movement taking place between the plates |
| shear stress | stress that occurs when forces act in parallel but opposite directions, pushing parts of a solid in opposite directions |
| tension | stress that occurs when forces act to stretch an object |
| compression | stress that occurs when forces act to squeeze an object |
| vent | an opening at the surface of the Earth through which volcanic material passes |
