Earthquake Machine, part 2

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Earthquake Machine, part 2
Mechanical Modeling to Increase Student
Understanding of Complex Earth Systems
Developed by Michael Hubenthal - IRIS Consortium
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Objectives

• Describe global trends for Earthquake occurrence
  and magnitude
• Interpret a Gutenberg Richter plot (Frequency vs.
  Magnitude)
• Critically analyze an argument
• Describe the importance of sharing science
  results with peers in the science process

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Studying Earthquake Recurrence
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Developing arguments.
How many beads are in the box????
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Relationship of slip to magnitude
Seismic Moment Mo fault length x fault width
x displacement x rigidity
Moment Magnitude Mw log Mo/1.5 10.7
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Visualizing magnitude with the model
Seismic Moment Mo fault length x fault width x
displacement x rigidity
Moment Magnitude Mw log Mo/1.5 10.7 In
earthquake machine, this means magnitude is
directly related to fault displacement
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• There are long periods of quiet
• between earthquakes

Most earthquakes are huge, deadly and
destructive events
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There hasnt been an earthquake in a long time
therefore the next one must be huge.
Extra credit
Develop an argument either for or against one
statement based on your experimentation with the
earthquake machine.
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There are always long periods between
earthquakes.
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All earthquakes are huge, deadly, and
destructive events
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Time Predictable
Slip Predictable
Characteristic
Stress
Slip
Time
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Calaveras Fault Data
(Bufe et al., 1977)
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Seismicity of the EQ Machine - 67 Years
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Seismicity of the EQ Machine - 163 Years
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Summary

• There are many more small earthquakes than large
  earthquakes
• There are more short time periods between
  earthquakes than long time periods
• In the earthquake machine, the longer since the
  last earthquake, the larger the earthquake is
  likely to be
• This isnt usually true in the Earth