Mid mantle scatterers near the Mariana slab detected with a double array method

We use a cluster of deep earthquakes, the fore- and aftershocks of the 23-A UG-1995 Mw=7.1 (18.8N, 145.33, h=595 km) event in the Mariana subduction zo ne as source array to locate where waves scatter near the deep slab. In ord er to obtain the high-precision location needed in this context, we first r elocate the events with a modified master event technique. Using the double beam method on the relocated events and data from the Warramunga array in Australia, we identified two non-standard S-to-P conversions arriving about 20.5 and 24 s after the P-wave. The corresponding scatterers are approxima tely located at a depth of 790 km (720 km) and a distance of 0.9 degrees to the southeast (2.3 degrees to the southwest) of the main shock. The scatte rers positions correspond to the location of lithosphere subducted below th e 660 km discontinuity.