How do you calculate earthquake amplitude?
Jul 29, 2010
in
Earthquake Questions
What is the amplitude (in mm) registered on a standard seismograph (same as that used by Charles Richter) of a Magnitude 5 earthquake at 200km?
I don’t even know where to start with this problem D:
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2 comments
Jens H on July 29, 2010 at 10:48 pm
To calculate the magnitude you can use a Nomogram.
with it you can see that the Seismograph will have a amplitude of about 30mm
Check the source to see more
Jessica on July 29, 2010 at 10:48 pm
Yes. Jens is correct. The Richter scale is based on the recorded ground motion on a specific type of seismometer and the distance away from the earthquake. It’s an old scale that’s not really used anymore, but it’s instructive in helping people see how intensity of an earthquake can change over distance.
Given two of the three pieces of information (amplitude, distance, magnitude), you can find the third by fitting a line though the two pieces of information you do know on the nomograph that Jens provided the link to. Make a mark at magnitude 5, another mark at 200km, connect them in a line and see where that line goes through the amplitude line and there’s your amplitude.