A large crater caused by the violent explosion of a volcano that collapses into a depression
volcano that has low-silica magma with high levels of dissolved gas; produces "fire fountain" eruptions
A steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs piled up around a volcano's opening
A tall, cone-shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials.
Conduit or Pipe
The channel from the magma chamber to the vent to bring the magma to the surface.
A bowl-shaped area that forms around a volcano's central opening
The shaking that results from the movement of rock beneath Earth's surface.
The sudden return of elastically deformed rock to its undeformed shape.
The location on the surface directly above the focus
Point at the depth where the rocks ruptured to produce earthquakes; place where quake waves originate
Magma that reaches Earth's surface
Molten rock beneath the earth's surface.
Magma Plume or Chamber
large underground pool of molten rock sitting underneath the Earth's crust.
Modified Mercalli Scale
measurement system that describes the effects of the earthquake; uses Roman Numerals.
Moment Magnitude Scale
a more accurate scale used to express energy released by an earthquake based on size of the area of the fault that moves, average distance that the fault block moves, and rigidity of the rocks in the fault zone.
Primary or P Wave
A type of seismic wave which causes particles in the ground to move in a push-pull motion similar to a coiled spring
A logarithmic scale of 1 to 10 used to express the energy released by an earthquake based on ground motion.
Ring of Fire
A circle of volcanoes surrounding the Pacific Ocean.
Secondary or S wave
Seismic wave that moves rock particles at right angles to the direction of the wave
Waves of energy that travel through the Earth
A device that measures the strength of an earthquake.
A wide, gently sloping mountain made of layers of lava and formed by quiet eruptions
Seismic waves that travel along the Earth's surface
A huge destructive wave (especially one caused by an earthquake)
An opening in a volcano connecting the Magma to the surface.
A vent in Earth's crust through which molten rock flows