The main-shock (Mw, 6.3) and the aftershocks of the 'Les Saintes' earthquake sequence (French Indies) were analyzed to quantify highfrequency directivity effects. A correction method was applied to isolate source spectra within a large frequency range (0.5 to 25 Hz). Most of the aftershocks source spectra are fully consistent with a Brune spectrum pointsource shape and do not show any azimuthal dependence. The main-shock (Mw, 6.3) and the two largest aftershocks (Mw, 5.8, 5.3) show, however, a clear azimuthal dependence that indicates significant directivity effect. The discrepancy of the radiated spectral energy and the change in the corner frequencies introduced by directivity effects show that such an effect is significant at high frequency (from 1 to 25 Hz). Our data suggest that the amplitudes in the main-shock Fourier spectrum at directive sites are around a factor of 2.5 higher with respect to anti-directive sites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.