Term | Definition |
Shield Volcano | A type of volcano usually built almost entirely of fluid lava flows. |
Cinder Cone | A steep conical hill of tephra (volcanic debris) that accumulates around and downwind from a volcanic vent. |
Composite Cone | A conical volcano built up by many layers (strata) of hardened lava, tephra, pumice, and volcanic ash. |
Scoria Cone | Cinder Cone |
Stratovolcano | Composite Cone |
Hot Spot | An area of volcanic activity, especially where this is isolated. |
Fissure | A long, narrow opening or line of breakage made by cracking or splitting, especially in rock or earth. |
Caldera | A large volcanic crater, typically one formed by a major eruption leading to the collapse of the mouth of the volcano. |
Pahoehoe Flow | Basaltic lava forming smooth undulating or ropy masses. |
Block Lava | Basaltic lava in the form of a chaotic assemblage of angular blocks. |
Pyroclastic Flow | High-density mixtures of hot, dry rock fragments and hot gases that move away from the vent that erupted them at high speeds. |
Bomb | A lump of lava thrown out by a volcano. |
Lahar | A destructive mudflow on the slopes of a volcano. |
Aa Flow | Basaltic lava having a rough surface. |
Viscosity | The state of being thick, sticky, and semifluid in consistency, due to internal friction. |
Volatiles | Chemical species that under normal conditions of pressure and temperature exist in the gaseous phase. |
Continental Volcanic Arc | South America |
Intraplate Volcanism | Hotspot |
Volcanic Island Arcs | Offshore volcanoes. |
Pacific Ring of Fire | An area where a large number of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean. |