Investigation of the Dynamical Process in Earthquake Foci by Analyzing the Pulse Shape of Body Waves.

The shape of recorded teleseismic P-wave pulses is used to describe earthqakes in terms of propagating dislocations. The disturbing influences of seismograph system and wave propagation through the earths mantle and crust on the pulses are taken into account as far as possible or necessary. Model computations of synthetic body-wave pulses radiated from various types of propagating sources serve as a mean to interpret observed pulses. The analysis is carried out to some extent in the time domain and partially in the frequency domain. The method is applied to 17 deep-focus earthqakes from three seismic regions at the Kurile-Islands, the Fiji-Islands, and in Western-Brazil. The released total moment, faulted area, average dislocation and stress drop has been determined. Author