The Seismic monitoring system is used for the observation of natural earthquakes of magnitude 3 and under.
A natural earthquake of magnitude below 1 is termed “ultra-micro earthquake” for which one cannot feel the tremor. Of particular interests are earthquakes whose magnitude is a negative value and are referred to as a low frequency Acoustic Emission (AE).
Generally, the AE is the elastic wave radiated during the destruction or deformation of material and is observed in the high frequency KHz band. It is used for determining inner conditions of the material.
Recent high technology instruments for seismic monitoring have improved enough the resolution of observed data to be used as monitoring systems for observation of low frequency AE.
In addition to natural earthquake observation, the seismic monitoring system is also used as a monitoring tool, detecting cracking zones in rocks, caused by hydraulic fracturing for enhancing production of petroleum, natural gas and geothermal fluid. It also used to detect stress-induced cracks in rocks for maintenance and care of underground structures such as for petroleum storage.
JGI has developed and now marketing the following system.
MS-2000D catalogue(pdf)
