Geophone
Graphs of geophone data show peak ground vibration near the sensor. Sensor uses a geophone having a frequency response of 10 to 250 Hz at -3 dB, with a 300 Hz low pass filter, and a peak detector. Sources of ground vibration that may be recorded by the geophone include nearby earthquakes, thunder, wind in trees, and human or vehicle traffic. Rapid, catastrophic landslide movement would likely result in prolonged, strong ground shaking with high amplitude peaks in the data.
WARNING: Provisional data, subject to revision
NOTE - data available since March 22, 1997