"Conventional exploration for oil and gas reservoirs utilizes active seismic surveys. In these surveys, a pulse of seismic energy is generated by either a dynamite explosion or a vibrator truck, and the reflections of the seismic waves from underground structures are sensed by an array of seismic sensors (conventional geophones or newer MEMS sensors). By contrast, passive seismic sensing1 uses only naturally occurring seismic signals – from earthquakes and microtremors, ocean waves, and similar sources – to image subsurface structures. While conventional active seismic surveying utilizes the frequency range from ~10 – 300 Hz, passive seismic monitors lower frequency waves, which can travel long distances through the earth’s crust without attenuation.In recent years, however, intense interest has developed in using passive seismic sensing for oil and gas exploration due to the recognition that the very low end of the seismic spectrum – under 10 Hz – contains valuable information about the location of hydrocarbon reservoirs." For more click here
"MTRS-614 is the ultra small and lightweight rate sensor assembly. The sensors are characterized by high sensitivity and very low intrinsic noise level. The sensor is available in two versions. The MTRS614B is optimized to achieve low self noise, while the MTRS614A has lower g-sensitivity and consequently can deliver better performance where vibration is a factor conditions." For more click here
