seismometer

/sɑɪzˈmɒmɪtər/

Other forms: seismometers

A seismometer is a scientific instrument used to detect earthquakes. When the ground shakes, a seismometer can measure exactly how much it's moving up and down.

Seismometer comes from the Greek roots seismos, "a shaking," and metron, "a measure." During the 2nd century, a Chinese astronomer invented a basic version of the seismometer that scientists still use today. A simple seismometer is made from a frame that is very sensitive to motion and a weight suspended from it by a spring. The measurement of earthquake activity comes from comparing the relative motion of the weight compared with the frame.

Definitions of seismometer

1. noun

   a measuring instrument for detecting and measuring the intensity and direction and duration of movements of the ground (as an earthquake)
   synonyms: seismograph

   type of:

   measuring device, measuring instrument, measuring system

   instrument that shows the extent or amount or quantity or degree of something