EARTHQUAKES

Cage Dix and Marc Hall

2nd period Advanced Earth Science

Mrs. Hirtz

CHAPTER 8 VOCABULARY Seismology- is the study of earthquakes Fault- is a break in the earths crust along which

blocks of the crust slide relative to one another due to tectonic plates

Deformation- the change in the shape of rock in response to stress

Elastic Rebound- the sudden return of elastically deformed rock to its original shape

Seismic Waves- waves of energy that travel through the earth

P-Waves- the fastest type of seismic waves S-Waves- the 2nd fastest type of seismic waves

Chapter 8 Vocabulary(Cont.) Seismograph- a instrument located at or near the surface of the earth

that records seismic waves Seismogram- a tracing of earthquake motion created by a seismograph Epicenter- the point on the earth’s surface directly above an

earthquakes starting point Focus- the point inside the earth where an earthquake begins Gap Hypothesis-states that sections at active faults that have had

relatively few earthquakes are likely to have strong earthquakes in the future

Seismic Gap-an area along a fault where relatively few earthquakes have occurred

Moho-a place within the earth where the speed of seismic waves increases sharply

Shadow Zone- an area on the earths surface where no direct seismic waves from a particular earthquake can be detected

Section 1 Earthquakes take place on tectonic plates. Numerous features called fault exist in the

Earth’s Crust. Earthquakes differ in strength and in depth of

where they occur. Transform motion occurs where two plates slip

past each other. Convergent motion occurs where two plates

push together. Divergent motion occurs where two plates pull

away from each other.

Section 1(cont.)

There are two types of seismic waves:

1)P-Waves

2)S-Waves P-Waves travel through solids, liquids,

and gases(they are the fastest seismic waves)

S-Waves are the second fastest waves.

Section 2Modified Richter Scale

Magnitude Estimated Effects

2.0 Can be detected only by seismograph

3.0 Can be felt at the epicenter

4.0 Felt by most in area

5.0 Causes damage at epicenter

6.0 Causes widespread damage

7.0 Causes great, widespread damage

Section 3

The highest earthquake level is in California.

Earthquakes that are higher in strength usually occur less in a period of time.

People in California are used to earthquakes now.

Earthquakes shake the ground out from under building like a judo master kicks the feet out from under is opponent.

Section 3(cont.)

They have started to build building and bridges to with stand earthquakes.

Put heavier items on lower shelves incase of an earthquake.

If you are in school and an earthquake begins duck under your desk and cover your head

Being in an earthquake is a startling experience.

Section 4

When you put a end of a pencil in water it looks bent seismic waves do much the same.

The first and perhaps most successful seismic test on another cosmic body was Earth’s moon.

Quakes happen everywhere the moon has a moonquake and even the sun can have a sun quake.

Work Cited

Earth Science Book

Copyright © 2004 by Holt, Rinehart and Winston