| A | B |
|---|
| magma | liquid rock, underground |
| volcanism | movement of magma towards surface |
| lava | liquid rock, surface |
| volcano | vent or fissure through which gases and magma come out |
| Ring of Fire | volcano zone around Pacific Ocean |
| subduction zone | one tectonic plate moves under another |
| trench | deep v-shape forms along subduction zones |
| island arc | string of volcanic islands |
| fissure | crack in Earth |
| hot spot | volcanically active area of Earth's surface |
| pluton | igneous rock formation |
| mafic | magma rich in Magnesium and Iron, dark colored |
| felsic | magma rich in feldspar and silica, light colored |
| pahoehoe | runny lava, forms ropey looking rock |
| aa | thick lava, forms chunks |
| viscosity | resistance to flow, how "thick and gooey" |
| pyroclastic material | fragments of rock that form during a volcanic eruption |
| ash | < 2 mm |
| dust | < 2.5 mm |
| lapilli | < 64 mm |
| bombs | spindle-shaped pyroclastic material |
| crater | funnel-shaped pit at top of volcano |
| caldera | huge opening created when a volcano top collapses into magma chamber |
