earthquake machine, part 2
DESCRIPTION
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) - PowerPoint PPT PresentationTRANSCRIPT
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
3
Studying Earthquake Recurrence
Developing arguments….
How many beads are in the box????
Seismic MomentMo = fault length x fault width xdisplacement xrigidity
Moment Magnitude = Mw = log Mo/1.5 – 10.7
Relationship of slip to magnitude
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Seismic MomentMo = fault length x fault width x displacement x rigidity
Visualizing magnitude with the model
B
Moment Magnitude = Mw = log Mo/1.5 – 10.7
In earthquake machine, this means magnitude is directly related to fault displacement
#1“There are long periods of quiet
between earthquakes”
Develop an argument either for or against one statement based on your experimentation with the earthquake machine.
“Most earthquakes are huge, deadly and destructive events”
Extra credit
#2“There hasn’t been an earthquake in a long time; therefore the next one must be huge.”
“There are always long periods between earthquakes.”
“All earthquakes are huge, deadly, and destructive events”
Characteristic Time Predictable
Slip Predictable
Str
ess
Sli
p
Time
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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