Volcanic Seismology pp 248-266
Nonlinear Inversion of S-Wave Polarization for Constraining the Source Mechanism of Small Earthquakes
- Cite this paper as:
- Zollo A., Bernard P. (1992) Nonlinear Inversion of S-Wave Polarization for Constraining the Source Mechanism of Small Earthquakes. In: Gasparini P., Scarpa R., Aki K. (eds) Volcanic Seismology. IAVCEI Proceedings in Volcanology, vol 3. Springer, Berlin, Heidelberg
An accurate estimate of micro-earthquake source mechanisms in volcanic areas may be obtained by using three-component S waveforms from near source records. S-wave polarizations recorded at the earth’s surface are here used to infer the parameters of a point-source double couple fault model (strike, dip and slip angles of the fault plane) for an earthquake. We define an error function associated to polarization misfits, and a related probability density function which is computed in the whole model space. Because of the small number of parameters, the probability density function can be represented on plane view projections. This gives a global image of the resolution pf model parameters by actual data. This method has been applied to estimate the source mechanism of an ML = 2 earthquake which occurred at the Campi Flegrei caldera during the recent seismic crisis of (1983–1984).
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