Fiber optic sensors for seismic wave detection

This paper proposes a fiber optic multi-parameter seismic observation system based on fiber optic interferometric sensors for seismic wave detection. The multi-parameter fiber optic seismic probe, including a 3-componet fiber optic seismometer a 4-componet strainmeter and a fiber optic temperature sensor, is developed using the fiber optic Michelson interferometers. The interrogator, using phase generating carrier technology, has a high resolution of 10-5 rad/Hz^1/2. The probe is installed in a 60m deep borehole for long-term observation. The observation results show that all sensors can detect the seismic wave signals of the earthquakes, even teleseismic earthquakes from the coast of Taiwan. Moreover, the fiber optic strain sensors also can measure the earth tide. The fiber optic multi-parameter seismic observation system is expected to provide rich data for seismic wave detection in seismology and geophysics.