A scientist who studies volcanoes and volcanic phenomena.
What is a volcanologist
100
A small (less than 400 meters high), cone-shaped volcano made of broken rocks or blobs of hardened lava, called “cinders,” that accumulate around the volcanic vent
What is a cinder cone
100
A zone of intense earthquake and volcanic activity that encircles the Pacific Ocean basin; also called the Circum-Pacific Belt.
What is the ring of fire
100
A solid earth material that forms when magma or lava cools and crystallizes on or below the earth’s surface
What is an igneous rock
100
Mudflow that occurs when rain falls through clouds of ash or when rivers become choked with falling volcanic debris
What is a lahar
200
A large, steep-sided, circular or oval volcanic depression that forms when magma retreats or erupts from a shallow underground magma chamber; with no magma to support the ground above it, the overlying rock collapses
What is a caldera
200
A zone of intense earth- quake and volcanic activity that runs down the middle of the Atlantic Ocean floor.
What is the Mid-Atlantic Ridge
200
A landform, usually cone-shaped, pro- duced by a collection of erupted material around a vent, or opening, in the surface of the earth and through which gas and erupted mate- rial pass.
What is a volcano
200
A solid earth material made of various minerals. Igneous, metamorphic, and sedimen- tary are three types of rock.
What is rock
200
Fragmented volcanic material with parti- cles that measure less than 2 mm in diameter.
What is ash fall
300
The tendency to resist flow; a prop- erty of liquids.
What is viscosity
300
A wide, broadly sloping volcano that forms from runny lava. It is the largest of volcanoes.
What is a sheild volcano
300
The ejection of volcanic materials into the atmosphere and the settling of these materi- als over a wide area of the surface of the earth
What is ash fall
300
A solid earth material com- posed of compacted and cemented sediments or of particles of various sizes
What is sedimentary rock
300
Lava that flows quickly over the sur- face of the earth and covers a wide area.
What is a lava flow
400
A localized zone of melting in the mantle that is fixed under a plate.
What is a hot spot
400
A volcano that forms from alternating eruptions of viscous lava and broken rock. It is steep near the summit and flat toward the base.
What is a composite volcano
400
A small, bowl-shaped hole that forms when rock explodes from a volcano during an eruption.
What is a crater
400
A solid earth material that forms when any rock type is changed by the earth’s high temperature and pressure.
What is a metamorphic rock
400
A powerful “river” of mud that forms when debris, such as from a volcanic eruption, moves into a stream or river.
What is a mudflow
500
Balloonlike mounds that form when lava erupts under water or empties into the ocean.
What is pillow lava
500
A naturally formed, inorganic solid composed of one or more elements.
What is a mineral
500
A bulbous, steep-sided dome that forms at the top of a volcano when thick, rela- tively “cold” magma emerges from the volcanic opening.
What is a lava dome
500
The process by which earth materi- als transform from one rock type into another.
What is the rock cycle
500
A huge sea wave caused by under- water earthquakes or, more rarely, by volcanoes.