As seismologists gained more experience from earthquake records, it became obvious that the problem could not be reduced to a single peak acceleration. In fact, a full frequency of vibrations occurs.
-- Charles Francis Richter
   
Charles Francis Richter   Name:
Charles Francis Richter
Type:
Scientist
Nationality:
American
Birth:
April 26, 1900
Death:
April 20, 1985
https://www.nutquote.com/quote/Charles_Francis_Richter