Energy that travels as vibrations on and in Earth
Seismic waves
Cause particles in the ground to move up and down in a rolling motion
Surface waves
Mercalli Scale
area of earthquake and volcanic activity that surrounds the Pacific Ocean
Ring of Fire
a liquid's resistance to flow
viscosity
The vibrations in the ground that result from movement along breaks in Earth's lithosphere
Earthquakes
Cause particles in the ground to move in a push-pull motion similar to a coiled spring. First wave to be detected
Primary waves
A graphical illustration of seismic waves
Seismogram
molten rock that erupts onto Earth's surface
lava
small, steep-sided volcanoes that erupt gas-rich, lavas
cinder cone volcano
A break in Earth's lithosphere where one block of rock moves toward, away from, or past another.
Fault
Cause particles to move up and down at a right angles relative to the direction the wave travels
Secondary waves
Uses the amount of ground motion at a given distance from an earthquake to determine magnitude
Richter Scale
Volcanoes that are not associated with plate boundaries
hot spots
tiny particles of pulverized volcanic rock and glass
volcanic ash
The location inside Earth where waves originate and rocks first move along the fault
Focus
scientists that study earthquake
seismologist
a vent in Earth's crust through which melted - or molten - rock flows
volcano
common along divergent plate boundaries and oceanic hot spots; large with gentle slopes
shield volcano
large volcanic depression formed when a volcano's summit collapses or is blown away by explosive acitivity
caldera
The location on Earth's surface directly above the earthquake's focus.
Epicenter
measures and records ground motion and can be used to determine the distance seismic waves travel
seismometer
molten rock below Earth's surface
magma
large, steep-sided volcanoes that result from explosive eruptions of lava and ash along convergent plate boundaries
composite volcanoes
avalanches of hot gas, ash, and rock produced by explosive volcanoes
pyroclastic flow