Investigation 2 Facts

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Investigation 2 Facts

• The Interior of the Earth

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Fault

• A break in Earths crust where rock on one side
  moves in relation to rock on the other side.

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Seismic wave

• A vibration in Earths crust, caused by the
  release of energy at a fault.

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Point of origins

• Focus
• The point inside Earth where a seismic wave
  begins.

• Epicenter
• The point of the Earth surface directly above the
  focus.

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Measuring Magnitude

• Richter Scale
• Charles Richter developed a scale that uses the
  size of waves to determine the magnitude of an
  earthquake.

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• Seismograph
• Any of various instruments for measuring and
  recording the vibrations of earthquakes.

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Seismologist

• Scientist that studies seismic waves.

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Tsunami

• An unusually large sea wave produced by a
  seaquake or undersea volcanic eruption.

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Types of Seismic Waves

• Body Waves
• Compressional Wave (P-Wave) Primary
• Shear Wave (S-Wave) Secondary

• Surface Waves
• Rayleigh Wave
• named for John William Strutt, Lord Rayleigh. He
  mathematically predicted this kind of wave in
  1885
• Love Wave
• named after A.E.H. Love, a British
  mathematician who discovered it in 1911.

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Investigation 2 Vocabulary

• Seismograph
• Shadow zone
• Physical model
• Conceptual model
• Mathematical model
• Numerical Model

• Average wave speed
• Compressional wave (p-wave)
• Shear wave (s-wave)
• Seismic wave
• Boundary
• Refraction
• Richter scale
• Magnitude

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Body Waves

• Compressional Wave
• Energy is compressed or squeezed together then
  released in a straight pathway.
• Able to flow through solids, liquids, and gases

• Shear Wave
• The second wave you feel in an earthquake.
• An S wave is slower than a P wave and can only
  move through solid rock.

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Surface Waves

• Rayleigh Wave
• A Rayleigh wave rolls along the ground just like
  a wave rolls across a lake or an ocean. Because
  it rolls, it moves the ground up and down, and
  side-to-side in the same direction that the wave
  is moving.

• Love Wave
• It's the fastest surface wave and moves the
  ground from side-to-side.

http//www.geo.mtu.edu/UPSeis/waves.html
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Refraction

• Wave refraction When a set of waves cross a
  boundary (change of material in the Earths
  surface) causing it to change speed and direction.

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Average Wave Speed

• The average speed a wave travels in a matter of
  seconds.
• Ave. wave speed distance (cm)
• time (s)

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Seismograph

• Records the magnitude of each wave as a passes a
  seismograph station.