Seismic sensors function as velocity sensors or accelerometers that sense the vibrations of the earth. Originally developed in the 1860s to detect earthquakes, these sensors are now also used for such purposes as resource exploration and security surveillance.
For security purposes, seismic sensors collect intelligence on what is happening in a designated area. They detect ground vibrations and process the information in real-time to alert operators of a security breach. Depending on the sophistication of the system, seismic sensors may be able to classify if the vibrations are being caused by people or vehicles, and where they are located.