what type of instrument measures seismic waves?
The released energy travels as shock waves, called seismic waves, which may be felt and measured. The study of seismic waves is known as seismology, a word derived from a Greek word meaning to shake.. Seismographs are the instruments which record earthquakes. Scientists use these instruments as their principal tool to study seismic waves. They are very sensitive instruments that can detect, measure and record ground vibrations and their intensities during an earthquake.