tsunami		An instrument for measuring and recording the vibrations of earthquakes.
epicenter		A point directly above the focus.
seismic waves		An intervening substance through which a force acts or an effect is produced
focus		Magma or igneous rocks consisting chiefly of feldspars, feldspathoids, quartz, and other light-colored minerals.
caldera		A vent in the earth's crust through which lava, steam, ashes, etc., are expelled.
magnitude		A movement of the ground that is caused by a sudden release of energy when rocks along a falut move
fault zone		A large sea wave produced by a seaquake or undersea volcanic eruption.
mafic		Magma or igneous rocks consisting of dark, ferromagnesian minerals
volcanism		The amount of damage caused by an earthquake.
body wave		A seismic wave that travels through the body of a medium.
fault		A seismic wave that travels along the earth's surface
volcano		A break in a body of rock along which one block slides relative to another
surface wave		A region of numerous, closely spaced faults.
intenstiy		The phenomena connected with volcanoes and volcanic activity.
magma		A large depression resulting from the explosion or collapse of the center of a volcano.
earthquake		Shock waves in solid rock generated by earthquakes or underground explosions.
felsic		A measure of the strength of an earthquake
medium		Liquid rock beneath or within the earth's crust, from which igneous rock is formed
shadow zone		The molten, fluid rock that issues from a volcano or volcanic vent.
seismograph		An area on Earth's surface where no direct seismic waves from a particular earthquake can be detected
lava		The point of origin of an earthquake.