Passive Seismic Monitoring in Hydrothermal Field: Seismic Emission Tomography

Authors: Yu. Kugaenko, V. Saltykov, V. Sinitsyn, V. Chebrov
Keywords: Seismic emission, seismic array, hydrothermal field, seismic emission tomography, passive seismic monitoring, Mutnovsky hydrothermal field
Conference: World Geothermal Congress Session: 7. Geophysics
Year: 2005 Language: English
Geo Location:
Abstract: For last years seismic noise has been considered as highly informative field, containing the unique information about a crust structure. The volumes of the crust in which stress condition is differ from background regional stress, radiate seismic noise most heavily. These are zones of increased concentration of cracks, the fractures, the hydroterms and volcanic areas.
In present investigation we use the method of noise seismotomography for reconstruction of endogen microseismic emission field, which was observed by seismic array in hydrothermal area. For localization of seismic radiation sources the parameter Semblance was used. Semblance is the ratio of signal energy summed over all sensors of the array to the sum of energies of individual sensors calculated for each point of medium under the array.
The registration was held in the region of the Mutnovsky geothermal field (Southeast of Kamchatka, Russia). The areas with the high seismic noise activity were detected. They are related to the steam-hydrotermal production zone. The spatial distribution of the active sources is agree with the production zone configuration, the temperature field structure, the distribution of two-phase state and mono-phase state of the heat-transfer in the production zone. Also, sources of induced microseismic emission have been detected as the result of the passage of seismic waves from the teleseismic earthquake.
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