Earthquake

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Earthquake

• By Candy Olson

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• Fault lines relief of stress
• Subduction
• normal faulting
• reverse faulting
• strikeslip
• transform
• http//www.iris.edu/gifs/animations/faults.htm

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tsunami

• http/www.pbs.org/wnet/savageearth/animations/tsun
  ami/main.html
• Danger
• -Getting knocked about by debris
• -Being pulled out to sea

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Observed phenomena

• Gas clouds-can be irritating, fatal, eclipse the
  sky
• Lightning
• Haze before, during and after a quake
• Water/steam geiser
• Sand, coal or other mineral geiser
• Land splits, drops, or raises

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seismograph

• Measurements
• 1st in China_at_135 C.E.
• Han dynasty-invented by Chang Heng

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• 1st modern day seismograph in 1875 by Cecchi in
  Italy used a suspended pendulum
• Work was done in 1880s in Japan that continued
  to improve on Cecchis work
• http//earthquake.usgs.gov/learning/kids/kidsLearn
  ingLinks.php

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Types of measurement

• Richter scale measures movement of suspended
  pen (seismograph) during a quake
• Seismic moment measures how much and how far
  the Earths crust moves during a quake

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Types of earthquakes

• Benioff zone- focus is deep in subduction zone
• Surface- focus is at or near the surface of the
  Earths crust
• http//www.pbs.org/wnet/savageearth/animations/ear
  thquakes/index.html

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How do scientists know where the focus is?

• One station recording a quake gives a circle of
  possibilites.
• Two stations give two possibilities.
• Three stations finds the location of the
  epicenter.
• Four stations finds the depth/ focus.

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Scientific advancement from studying earthquakes

• Have learned that entire plates can shake in a
  great quake
• Are learning what the interior of the Earth is
  made of/how its arranged.
• Are learning the geological history of the
  Earth.

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Lab activity

• http//web.ics.purdue.edu/braile/edumod/slinky/sl
  inky.htm