How is a seismograph similar to an X-ray?

Answer: Seismograph is an instrument that is used to measure the vibration of the earthquake. It is based on seismic waves. X ray is an electromagnetic energy wave that is used for CAT (computerized axial tomography) scan.

Hence, both seismic wave and X ray are energy waves.

The velocity of seismic waves is different in different media. Similarly, X ray loses its amplitude depending upon the dense layer of the tissue.