Finite fault source study of the Great 1994 Deep Bolivia Earthquake

We apply an empirical Green's function method to recordings of teleseismic body waves from the June 9, 1994 deep‐focus Bolivia earthquake. The far‐field source time functions reveal that rupture occurred on a sub‐horizontal fault plane. The main rupture began some 25 km to the east of the hypocenter, consists of three large subevents, and covers a total area of about 60×40 km ². The static stress drop is quite large, more than 150 MPa, and the obtained rupture velocity is less than 2 km/sec. While the total dimensions of the earthquake are large compared to estimates of the width of a metastable olivine wedge at this depth, the moment release is confined largely to a narrow band along an EW axis, and may be compatible with phase transitions within a thickened slab core.