Whats the relationship motion on a seismograph, versus true motion of the ground where the seismograph is loca?
Aug 21, 2009
in
Earthquake Questions
(Earthquakes question). What is the relationship of the motion on a seismograph versus the true motion of the ground where the seismograph is located?
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3 comments
3.14159265358979323846 on August 21, 2009 at 9:09 am
it’s opposite
Ryan P on August 21, 2009 at 9:09 am
no
mission cat on August 21, 2009 at 9:09 am
The seismograph measures the ACCELERATION of the earth. Acceleration is how fast the velocity of the ground increases (or decreases).
To find out how far the ground actually moves in feet, you must double integrate the seismograph signal.
The first integration of the acceleration yields the velocity.
The second integration yields the translation or position movement.