Earthquakes

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Earthquakes

• Chapter 19

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Focus vs. Epicenter
Focus

• _________ where the rock breaks and seismic
  waves begin can be at deep or shallow depths
• _________ point on the surface directly above
  the focus usually what is used to locate the
  position of an earthquake

Epicenter
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Seismic Waves
Primary

• _______ (P) Wave fastest, able to travel
  through liquids, energy travels in the same
  direction wave is traveling
• ________ (S) Wave slower, not able to travel
  through liquids, energy travels at right angles
  to direction wave is traveling
• ________ (L) Wave travels along the surface,
  responsible for most of the quakes damage

Secondary
Surface
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The interior structure of the earth is determined
by the pattern of seismic waves. The __________
is liquid so s-waves can not pass through.
outer core
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The difference in arrival times between p-waves
and s-waves is called __________.
lag time
The greater the lag time (shown here as the
distance between the two curves) the _________
the distance away from the earthquake.
greater
6
To locate the epicenter of an earthquake, a
minimum of ____ seismograph stations is needed.
The location is where all circles _______.
three
intersect
7
Faults Vocabulary
Fault Plane

• __________ surface along which rock layers move
• __________ rock layers above the fault plane
• __________ rock layers below the fault plane
• ________ angle with the surface the fault plane
  makes going down into the ground
• ________ direction along the surface the fault
  plane creates

Hanging Wall
Footwall
Dip
Strike
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Faults
Normal

• _______ Hanging wall moves down formed from
  tensional forces
• _______ Hanging wall moves up formed from
  compressional forces
• ________ Hanging wall and Footwall move
  horizontally past each other formed from shear
  forces

Reverse
Strike-Slip
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Normal Fault
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Reverse Fault
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Strike-Slip Fault
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Folds
Anticline

• __________ A-shaped or hump-shaped fold with
  older rock layers in the center formed from
  compressional forces
• __________ U-shaped fold with younger rock
  layers in the center formed from compressional
  forces
• Anticlines and Synclines usually occur together
  and can be large or small scale

Syncline
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Anticlines and Synclines
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Other Vocabulary
seismograph

• ____________ instrument used to measure seismic
  waves
• __________ difference in arrival times of p-
  and s-waves
• ___________ rates earthquake by magnitude
  (amount of energy released)
• __________________ rates earthquake by amount
  and type of damage
• ______________ area of great vertical offset
  along strike of fault
• __________ large ocean wave caused by vertical
  movement of ocean floor due to an earthquake

lag time
Richter scale
modified Mercalli scale
fault scarp
tsunami
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Earthquake Review

• The fastest seismic wave which can travel through
  liquids is a ___________.
• The Richter scale measures an earthquakes
  ____________.
• A U-shaped fold with the rock layers are
  _________ in the center is a(n) __________.
• A _________ fault is formed when the hanging wall
  moves up due to __________ forces.

P-wave
magnitude
younger
syncline
reverse
compressional