What is a digital seismograph?
Just as a microphone and tape recorder are used to receive and save the acoustic waves produced by an orchestra, a seismograph is used for seismic waves. Of course, the human ear can hear the acoustic waves of music; and it can directly sense the passage of seismic waves if a large earthquake is nearby. However, to obtain an accurate permanent record of the ground motion, and to look at earthquakes occuring around the world, a more sensitive instrument is needed. A complete seismographic station is composed of: (1) a seismometer that continuously translates ground motion into an electrical output; (2) some method to permanently record this output, e.g., on a piece of paper for analog recording, or in a computer file for digital recording; and (3) time, the seismograph must keep accurate time. In addition, modern digital seismographs add a fourth component: display, “user-friendliness”, and rapid data transfer. MichSeis and OhioSeis seismographs emphasize “user-friendliness”. The Macint
