Estimation of earthquake source parameters of the May 4, 1972 event of the Hellenic arc by the inversion of waveform data


Average source parameters of the May 4, 1972 (Ms = 6.5) earthquake, southwest of Crete, are obtained by the inversion of body waves. A source depth of 40 km is determined, which places the source in the mantle. The source parameters of the major double-couple are: strike = 309 °; dip = 18 °; rake = 89 ° and seismic moment M0 = 2.62 × 1025 dyn cm. The source-time function is of ∼ 5 s duration with a long rise time. The mechanism obtained corresponds to a pure thrust with the P-axis almost perpendicular to the Hellenic arc. Although a point source is assumed, the resulting synthetics match satisfactorily the observed waveforms. © 1989.

Publication Title

Physics of the Earth and Planetary Interiors