SEISMIC SENSOR, EARTHQUAKE DETECTION METHOD, AND EARTHQUAKE DETECTION PROGRAM

A seismic sensor 10 comprises an acceleration acquisition unit 21, an earthquake determination unit 25, an offset adjustment unit 29, a convergence determination unit 29a, and an origin correction necessity determination unit 29b. After the detection of noise included in the vibration detected by the earthquake determination unit 25, the offset adjustment unit 29 adjusts the offset amount according to the magnitude of the vibration. The convergence determination unit 29a determines whether or not the vibrations have converged. The origin correction necessity determination unit 29b determines whether or not to perform the origin correction of acceleration according to whether or not the offset amount calculated according to the magnitude of the vibration after noise was detected is about the same as the previous offset amount, at the point when a specific period has elapsed since the time when the convergence determination unit 29a determined that the vibrations had converged.