Seismometer

File:Kinemetrics seismograph.jpg

Strong motion seismometer.

Seismometer or seismograph is an instrument that measures motions of the ground, including those generated by earthquakes, nuclear explosions and other sources. Records of seismic waves called seismograms allow to map the interior of the Earth, and locate and measure the size of those different sources.

The word derives from the Greek word, seismós, a shaking or quake, from the verb σείω, seíō, to shake; and μέτρον, métron, measure.

Other websites

• The history of early seismometers
• A Java code applet demonstrating the operation of a damped-mass seismometer
• Keeping track