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Earthquake Machine, part 2
Mechanical Modeling to
Increase Student
Understanding of Complex
Earth Systems
Developed by Michael Hubenthal - IRIS Consortium
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
Studying Earthquake
Recurrence
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Developing arguments….
How many
beads are in the
box????
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
Visualizing magnitude with the
model
B
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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#1
#2
Extra credit
“There are long periods of quiet
between earthquakes”
“Most earthquakes are huge,
deadly and destructive events”
“There hasn’t been an earthquake
in a long time; therefore the next
one must be huge.”
Develop an argument either for or against one
statement based on your experimentation with the
earthquake machine.
“There are always long periods between
earthquakes.”
“All earthquakes are huge, deadly, and
destructive events”
Time
Predictable
Stress
Characteristic
Time
Slip
Predictable
Calaveras Fault Data
(Bufe et al., 1977)
Seismicity of the EQ Machine - 67 “Years”
Seismicity of the EQ Machine - 163 “Years”
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 isn’t usually true in the Earth
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