seismometer

1. (geology) A device used by seismologists to detect and measure seismic waves and therefore locate earthquakes etc; a seismograph.Examples: "Despite the Hebgen Lake quake and the other known risks, Yellowstone didn't get permanent seismometers until the 1970s."; "Researchers monitor the volcano through instruments and cables that extend from the coast. Among them are seismometers, which provide real-time data on the earthquakes occurring near the volcano, Chadwick said."