What instrument is used to measure seismic waves?

The instrument used to measure seismic waves is a seismometer. This device detects and records the energy released during seismic events, such as earthquakes. Seismometers can provide valuable data on the magnitude, duration, and type of seismic waves generated by these events. They work by recording the motion of the ground as seismic waves pass through it, allowing scientists to analyze the movement and characteristics of these waves.

In contrast, a barometer measures atmospheric pressure, which is unrelated to seismic activity, and a thermometer is designed to measure temperature. An accelerometer measures acceleration forces and can be used in various applications, including detecting ground motion, but it is not specifically designed for the detailed analysis of seismic waves like a seismometer is. Therefore, the seismometer is the correct choice as it directly relates to the measurement and study of seismic waves generated by geological activity.