POSSIBILITY TO MONITOR THE STATE OF SEISMOGENIC MEDIA USING p PARAMETER
V.I. Shcheglov
Institute of Petroleum Geology and Geophysics, Siberian Branch of the RAS,
3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
Keywords: Seismogenic medium, effect-response, source parameters, space-time variations, earthquake prediction
Pages: 789-799
Abstract
The paper presents an energy model of an earthquake source as a basis for estimating quantitative source parameters. Stress drop (Δσ), slip ( D ), and the source length ( L ) and width ( W ) are found using the integral source parameter p as
p = 2( 4 / π ) VS / CL ) 3 √ E c / M 0
where Esis the seismic energy, M0 is the seismic moment, f0 is the angular frequency, CL is the velocity of dislocation front in the source, VS is the shear wave velocity, Δ ε is the strain drop.
In terms of physics the parameter p is an integral parameter of a seismogenic medium which characterizes its response to propagating dislocation. Its true values, as well as the values of other dynamic parameters, are impossible to estimate, the solution of the inverse source problem being ambiguous. Yet, there is no need in true values as the necessary information comes from space-time variations of p and other source parameters. This approach may allow more efficient solutions to the problems of earthquake prediction and seismic zoning.
Results of mass measurements of the p arameter show that it varies in earthquakes of the same energy class as a function of energy flux to the source area (e.g., the water level rise of the Nurek water reservoir). Space-time variations in the p parameter can be used as diagnostic for the location and time of pending events.
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