[ v o l c a n o e s : g l o s s a r y ]
Below are definitions of important volcano terms.
- active volcano: a volcano erupting or liable to erupt
- caldera: a large, more or less circular, more-than-a-mile-in-diameter depression formed either by collapse or by explosion, usually at the summit of a volcano
- continental drift: the breakup of the earth’s original single landmass into continents that then separated; they are still drifting apart today
- cinders: nut-sized pieces of red or black lava containing bubble-like cavities known as vesicles
- crust: the outside solid part of the earth’s surface
- dormant: when a volcano remains inactive for a long time
- eruption: the sudden emergence of hot material from the earth’s interior
- extinct volcano: volcanoes no longer liable to erupt
- fire fountain: a jet of magma spouting from a narrow volcanic vent
- fissure volcano: a long crack in the Earth’s crust through which magma erupts
- lahars: volcanic mudflows and debris flows
- lava: liquid, molten rock
- magma: hot molten rock created by the partial melting of the crust and mantle at high temperatures far below the ground
- magma chamber: a cavity beneath a volcano where magma collects
- plug: a tower of hard rock left by a volcano
- pyroclastics: volcanic solids like rock, cooled lava, etc.
- scoria: bubble-filled stones ejected from a volcano
- subduction zones: areas where the crustal layer descends into the mantle
- tectonic plates: 70-mile-thick blocks of the earth’s crust on which the continents ride
- tephra: fragments thrown into the air by a volcanic eruption
- vent: the single hole from which magma erupts
- volcanic cone: a conical mountain built up by volcanic eruptions
- volcanic crater: a steep-walled depression at the top or on the flank of a volcanic cone, out of which the volcanic materials are ejected
- volcanic sunset: a colorful sunset following a volcanic eruption
- volcano: a gap in the earth’s crust where molten rock and other materials escape onto the Earth’s surface
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Forces of Nature: ThinkQuest 2000 (Team #C003603)
http://library.thinkquest.org/C003603/english/volcanoes/glossary.shtml