| A | B |
|---|
| aa | a basaltic lava flow of rough, jagged chunks lava is high in silicon and or cooler than other lava |
| caldera | large, crater-shaped basin formed after the top of volcano collapses |
| cinder cone | cone-shaped volcano formed from lava fragments |
| composite volcano | volcano made of layers of hardened lava flows and pyroclastic materials |
| hot spot | area of volcanic activity distant from plate boundaries; in effect, a hole melted in the plate |
| lahar | a fast moving mudflow |
| lava | magma that reaches Earth's surface |
| lava plateau | plateau formed from basaltic lava |
| pahoehoe | a basaltic lava flow, having a smooth, ropelike surface and fluidity |
| pillow lava | lava that cools under water and has a pillow-like shape |
| pyroclastic flow | superheated cloud of gases and pyroclastic materials |
| pyroclastic material | solid rock fragments that are ejected during a volcanic eruption |
| shield volcano | volcano with a broad base and gently sloping sides |
| viscosity | a substance's resistance to flow |
| volcano | an opening in Earth's crust through which molten rock, gases, and ash erupt |
