Earthquake seismograph development: A modern history—Part 1


  • Ben S. Melton


The years from 1948 through 1976 saw numerous changes in electrodynamic-type earthquake seismographs. During this period, these seismographs and their associated amplifiers, recorders, timing systems, and power supplies were adapted for worldwide service under many operating conditions. These developments required and led to a better understanding of the fundamental limitations on design, ultimately allowing small but adequately sensitive instruments to be built for installation in cased holes, thereby avoiding undesired local surface disturbances. The recording system developed within this period permits ready review and compact storage of seismological data.