Intense seismic scattering near the core-mantle boundary beneath the Comoros hotspot, Geophys

Abstract. PKP phases observed in Japan show strong pre-cursors with clear onsets for earthquakes that occurred in south America. The onset times of the PKP precursors can all be explained by existence of seismic scatterers in the low-ermost 100 km of the mantle west of Mexico, within an area of 200 km 300 km. Forward modeling of PKP precursor amplitudes indicates that a P-wave velocity variation of at least 6 % is required to explain the large amplitudes of the observed PKP precursors, suggesting that the core-mantle boundary region beneath west of Mexico is a highly anoma-lous region characterized by strong seismic scatterers