Across
- 2. A spray of molten lava propelled a few tens to hundreds of feet (meters) into the air by rapid expansion of gas bubbles. They may erupt from vents or form in an active lava lake. Fire fountains most commonly occur in basaltic lavas erupted in Effusive (Hawaiian) eruptions. Also called a lava fountain.
- 4. An accumulation of highly molten bombs that landed while still molten and welded together to form solid rock, spatter cones, or sometimes feed lava flows. Spatter is formed from fire fountains. Spatter deposits are typically only formed near a vent.
- 6. The opening or place at Earth's surface through which magma, rock fragments, and/or volcanic gases are emitted.
- 8. A steep-sided mass of viscous, commonly blocky, lava extruded from a vent; typically has a rounded top and covers a roughly circular area; may be isolated or associated with lobes or flows of lava from the same vent; typically silicic (rhyolite or dacite) in composition.
- 11. A collective term used for all pyroclastic material, regardless of size, shape, or origin, ejected into the air during a volcanic eruption.
- 12. A colloquial term for a small nut-size to fist-size, or larger, piece of red or black highly vesicular lava that cooled in air during flight after eruption from a vent. The term is roughly synonymous with scoria.
- 13. An outpouring of molten rock from a vent onto Earth's surface during an effusive volcanic eruption; also the resulting solidified body of rock.
- 14. A collective term covering a wide variety of slope-movement landforms and processes that involve the downslope transport of soil and rock material en masse under the influence of gravity. On volcanoes, landslides may occur during or soon after volcanic eruptions or at other times.
- 15. A body of lava, consisting of one or more lava flows, that is the product of a single eruption.
- 16. The channel way or passage, which may be pipe-shaped, that brings magma from a reservoir or chamber to the vent at the surface where it is erupted.
- 18. A hazy mixture of sulfur dioxide (SO2) gas and aerosols of sulfuric acid and other sulfates created when volcanic gases interact with oxygen and moisture in the atmosphere and sunlight. Short for "volcanic smog."
- 19. A new area or region of a lava flow formed where lava from the molten interior of a previously-formed lobe breaks out through its sides or upper margin to create a distinct lava flow advance.
- 20. A white cloud of a mixture of condensed seawater steam, hydrochloric acid gas, and shards of volcanic glass produced when lava boils seawater to dryness. Short for "lava haze."
- 22. A vent or opening at the surface where volcanic gases and vapors are emitted.
Down
- 1. Molten rock beneath Earth's surface capable of intrusion and extrusion.
- 3. A hill made up of cinders that is a fragment of a cinder cone that was carried away by a lava flow erupted from a side vent near the base of the cone.
- 5. Pyroclastic flows are hot density currents of pumice, ash, blocks, and volcanic gas that rapidly move down the slopes of a volcano. They may be initiated by collapse of eruptive columns, by explosive eruptions that boil over, and by the collapse of lava domes.
- 7. A cloud of volcanic ash, tephra, and gases that forms downwind of an erupting volcano.
- 8. flow An outpouring of molten rock from a vent onto Earth's surface during an effusive volcanic eruption; also the resulting solidified body of rock.
- 9. Fine fragments (less than 2-4 mm in diameter) of volcanic rock formed by a volcanic explosion or ejected from a volcanic vent.
- 10. A pyroclast with a diameter greater than 64 mm (2.5 inches) with a rounded or ellipsoidal shape that indicates that it was wholly or partially molten during eruption and flight.
- 14. Conduit through which lava travels beneath the surface of a lava flow; also, a cavernous segment of the conduit that remains after the flow of lava ceases.
- 17. A vertical pillar of superheated volcanic ash, tephra, and gases ejected from a volcanic vent during an explosive eruption. Eruption columns usually spread laterally into eruption clouds higher in the atmosphere.
- 21. Molten rock beneath Earth's surface capable of intrusion and extrusion.