How can we help?

You can also find more resources in our Help Center.

20 terms

Ch8 iScience Vocab.

STUDY
PLAY
earthquake
shaking and vibration at the surface of the earth resulting from underground movement along a fault plane of from volcanic activity
fault
(geology) a crack in the earth's crust resulting from the displacement of one side with respect to the other
sesimic waves
energy from inside earth
focus
The point beneath Earth's surface where rock breaks under stress and causes an earthquake
epicenter
the point on the Earth's surface directly above the focus of an earthquake
primary waves
waves that travel outward from an Earthquake's focus and cause particles in rocks to move back and forth in the same direction the wave is moving
secondary waves
waves that travel outward from an earthquke's focus and move through Earth by causing particles in rocks to vibrate at right angles to the direction of the wave
surface waves
waves of energy that reaches Earth's surface during an earthquake, travel outward from the epicenter, and move rock particles up & down & side to side
seismologist
a scientist who studies earthquakes
seismometer
Instrument used to measure horizontal or vertical motion during an earthquake.
seismogram
the record of an earthquake's seismic waves produced by a seismograph
volcano
a fissure in the earth's crust (or in the surface of some other planet) through which molten lava and gases erupt
magma
molten rock in the earth's crust
lava
rock that in its molten form (as magma) issues from volcanos
hot spots
areas of volcanic activities that result from plumes of hot solid material that have risen from deep inside earths mantle
shield volcano
a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions
composite volcano
volcano built by alternating explosive and quiet eruptions that produce layers of tephra and lava; found mostly where Earth's plates come together and one plate sinks below the other
cinder cones
Form when lava is thick and stiff and has a cone-shape.
volcanic ash
sand-sized particles of igneous rock that form when a spray of liquid magma is blown from a volcanic vent by escaping gas
viscosity
resistance of a liquid to sheer forces (and hence to flow)