| A | B |
|---|
| gap hypothesis | a major earthquake is more likely to occur along the part of an active fault where no earhtquakes have occurred fo a certain period of time |
| seismic gap | an area along a fault where relatively few earthquakes have occurred recently |
| volcano | a vent or fissure in the Earth's surface through which magna and gases are expelled |
| magma chamber | the body of molten rock that feeds a volcano |
| vent | an opening at the surface of the Earth through which vocanic material passes |
| crater | a funnel-shaped pit near the top of the central vent of a volcano |
| caldera | a large, semicircular depression taht froms when the magma chamber below a volcano partially empties and causes the ground above to sink |
| lava plateau | a wide, flat landform that results from repeated nonexplosive eruptions of lave that spread over a large area |
| rift zone | an area of deep creack that froms betwee two tectonic paltes that are pulling away from each other |
| hot spot | a volcanically active area of Earth's surface far from a tectonic plate boundary |
