How Does a Seismometer Work?

Novice Spanish

A seismograph is a device for measuring the movement of the earth, and consists of a ground-motion detection sensor, called a seismometer, coupled with a recording system. This fact sheet provides an overview of the basic components of a seismometer and physical science principles behind its operation.

 

Keypoints:

  • A seismograph is a device for measuring the movement of the earth, and consists of a ground- motion detection sensor, called a seismometer, coupled with a recording system.
  • Seismographs operate on the principle of inertia
  • Seismometers used in earthquake studies are highly sensitive to ground movements, so that movements as small as 1/10,000,000 centimeters (distances almost as small as atomic spacing) can be detected at very quiet sites.
  • Modern research seismometers are electronic, and detect and record motions in all directions. 

 

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Related Animations

Animation of the principles of a drum-style horizontal seismograph station that records back- and-forth (N-S, E-W) movement.

Animation Novice

Animation of the principles of a drum-style vertical seismograph station that records up-and-down movement.

Animation Novice

The "moment magnitude" scale has replaced the Richter scale for large earthquakes. Scientists have developed far-more sensitive seismometers that, with faster computers, have enabled them to record & interpret a broader spectrum of seismic signals than was possible in the 1930's, when the Richter magnitude was developed. Find out what scientists learn from seismograms.

Animation Novice

Related Software-Web-Apps

jAmaSeis is a free, java-based program that allows users to obtain and display seismic data in real-time from either a local instrument or from remote stations.

Software-Web-App Novice

Explore earthquakes near you or from around the globe using the new IRIS Station Monitor app! Select from hundreds of seismic stations throughout the world. View up-to-the-minute recorded ground motions or see recordings from previous days and past events. Get information about recent events and choose to annotate wave arrivals.

Software-Web-App Novice

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