Adopting the moment and slip dimension, the stress drop of this event is estimated to be 7.6 Mpa. The slip distribution to the east of the epicenter roughly coincides with the location of the second subevent which was determined 12 s after the first subevent in the source process. Due to the trade-off between the subevent source parameters and structural noise the determination of the smaller subevents is not stable. The separation of the two events decreases in the waveforms recorded by stations at further distances to the west, which may offer a support for the second subevent to have occurred to the east of the epicenter. The source process determination for this event will benefit from a careful analysis of the inversion parameters, but also from better-constrained velocity models in different azimuths of ray path propagations.
Preliminary results are nevertheless consistent with other studies, and encouraging.
References Antolik, M., New results from studies of three outstanding problems in local, regional, and global seismology, Ph.D. Dissertation, Univ. Calif. Berkeley, 1996. Antolik, M., D. Dreger, and B. Romanowicz, Finite fault source study of the great 1994 Bolivia earthquake, Geophys. Kikuchi, M., and H. Kanamori, Inversion of complex body waves-III, Bull.