Your Name _______________________Period ______ Date __________
Chapter 12 Earth Science Word Study – Earthquakes
Directions: Study the following words by reading and rereading them each
evening so you will be prepared for the word study test each week. You may use
one index card to write as many words and definitions on as possible to use for the
test. The card must written in ink, be in your handwriting, and have your name,
period, and chapter recorded in the top, right corner with no obvious erasures or
mark outs. If all the criteria are met, you may use your index card during the
test. It will then be stapled to your test.
1.) earthquake - a movement or trembling of the ground that is caused by a
sudden release of energy when rocks along a fault move
2.) elastic rebound - the sudden return of elastically deformed rock to its
undeformed shape
3.) focus - the location within Earth along a fault at which the first motion of
an earthquake occurs
4.) epicenter - the point on Earth's surface directly above an earthquake's
starting point, or focus
5.) seismic wave - vibrations that travel in all directions which are released as
rocks along a fault slip into new places
6.) body wave - in geology, a seismic wave that travels through the body of a
medium
7.) surface wave - in geology, a seismic wave that travels along the surface of
a medium and that has a stronger effect near the surface of the medium
than it has in the interior
8.) P wave - a primary wave, or compression wave or a seismic wave that
causes particles of rock to move in a back-and-forth direction parallel to
the direction in which the wave is traveling; P waves are the fastest
seismic waves and can travel through solids, liquids, and gases
9.) S wave - a secondary wave, or shear wave, or a seismic wave that causes
particles of rock to move in a side-to-side direction perpendicular to the
direction in which the wave is traveling; S waves are the second-fastest
seismic wave and can travel only through solids
10.) shadow zone - an area on Earth's surface where no direct seismic waves
from a particular earthquake can be detected
11.) fault zone - a region of numerous, closely spaced faults
12.) lithosphere - the solid, outer layer of Earth that consists of the crust and
the rigid upper part of the mantle
13.) asthenosphere - the solid, plastic layer of the mantle beneath the
lithosphere; made of mantle rock that flows very slowly, which allows
tectonic plates to move on top of it
14.) mesosphere - literally, the "middle sphere"; the strong, lower part of the
mantle between the asthenosphere and the outer core
15.) outer core - a dense liquid under the mesosphere
16.) inner core - a dense, rigid solid in the center of the Earth
17.) convergent oceanic environment - plates that move toward each other
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and collide with the denser plate subducting or sinking beneath the other
and it can occur between two oceanic plates or one oceanic plate and one
continental plate
divergent oceanic environment - plates move away from each other like in
mid-ocean ridges with earthquakes occurring because oceanic lithosphere
is pulling away from both sides of each ridge
continental environment - as continental plates collide, the rock
surrounding the boundaries to experience stress as mountains form
causing frequent earthquakes
seismograph - an instrument that records vibrations in the ground
seismogram - a tracing of earthquake motion that is recorded by a
seismograph
magnitude - a measure of the strength of an earthquake
moment magnitude - a measurement of earthquake strength based on the
size of the area of the fault that moves
Richter scale -measures the ground motion from an earthquake to find the
earthquake's strength and is gradually being phased out
intensity - in Earth science, the amount of damage caused by an
earthquake
Mercalli scale - expresses intensity in Roman numerals from 1-12 with the
most destructive earthquake is 12 or total destruction
tsunami - a giant ocean wave that forms after a volcanic eruption,
submarine earthquake, or landslide
seismic gap - an area along a fault where relatively few earthquakes are
known to have occurred in the past
foreshocks - little earthquakes that occur before a larger quake by a few
seconds or a few weeks