Terms in this set (45)
Currently erupting or dormant, having erupted within the past 10,000 years and expected to erupt within the next 10,000 years
A dark volcanic rock with a silica content of about 60%. Andesite is the
second most abundant volcanic rock in the Earth's crust.
a layer of gases surrounding the earth
A dark volcanic rock with a silica content of 40 to 50%. Basalt makes upmost of the ocean floor and is the most abundant volcanic rock in the Earth's crust.
a large bowl shaped crater formed by explosive volcanic eruptions and/or by collapse of the volcano's surface material into the magma chamber.
Light fragments of lava, formed from lava ejected, cooled, and fragmented in the air, and falling back to earth. Also called "scoria".
A small, steep-sided volcano composed primarily of loose cinders or tephra.
A cone-shaped volcano built from alternating layers of pyroclastic material and viscous andesitic lava. (It is also called a Stratovolcano.)
A cone-shaped volcano built from alternation layers of pyroclastic material and viscous andesitic lava. (It is also called a Stratovolcano.)
Convective eruption column
A shaft of heat and airborne particles rising vertically from an erupting volcano.
Colliding, coming together.
Separating, breaking apart.
An active, but not currently erupting, volcano.
Vibrations induced in the Earth's crust by the abrupt rupture and rebound of rocks in which strain has been slowly accumulating.
The point on the Earth's surface directly above the origin of disturbance that creates an earthquake.
The ejection of molten rock, steam, gas, ash, and other pyroclastic material from a volcano or geyser.
Having ceased erupting; no longer active.
A fracture along which pieces of the Earth's crust move relative to one another.
The belowground point of origin of an earthquake. Also called a "hypocenter".
An upwelling of magma from beneath the Earth's crust, caused by a disturbance at the boundary between the solid mantle and the liquid outer core.
A massive flow of mud, pyroclastic material, and debris that descends from a volcano, typically along a river valley.
Magma or molten rock that erupts onto the Earth's surface.
Very hot molten rock, which is formed within the Earth by partial melting of the Earth's crust and mantle.
A cavity in the lithosphere where rising magma collects prior to an eruption.
Change from one polarity to the opposite polarity.
The portion of the Earth's interior between the crust and the core.
A theory in which the lithosphere is divided into a number of crustal plates, each of which moves on the plastic asthenosphere more or less independently to collide with, slide under, or move past adjacent plates.
Cinder with so many gas chambers, it can float on water.
A cloud of superheated gas, ash, and rock that erupts from a volcano and travels quickly down slope.
pyroclastic flow deposit
A layer of ash and rock deposited by a pyroclastic flow. These can be many meters thick.
A portion of the Earth's crust, bounded on at least two sides by faults, that has dropped downward in relation to adjacent crust; a "graben".
Waves of energy that travel through the Earth and cause the shaking experienced during earthquakes.
A low, broad, gently sloping, dome-shaped volcano that forms over time as repeated eruptions eject basaltic lava through one or more vents and the lava solidifies in approximately the same volume all around.
A cone-shaped volcano built from alternating layers of pyroclastic material and viscous andesitic lava. (It is also called a composite volcano.)
The process by which one tectonic plate is drawn down or overridden by another.
The region where one lithospheric plate descends beneath another plate and dives into the asthenosphere.
A section of the Earth's crust and lithosphere that moves above the asthenosphere.
Fragmented material of various sizes produced by a volcanic eruption. Tephra includes ash, cinders, and volcanic bombs or blocks.
Sliding past each other.
The lowest layer of the Earth's atmosphere.
A huge ocean wave generated by earthquakes or violent volcanic eruptions.
Having a relatively high resistance to flow; thick and sticky.
A cone formed above and around a vent as erupted volcanic materials, including ash, pumice, lava, and other volcanic debris, accumulate.
The scientific study of volcanoes.