BEAM-STACK IMAGING USING A SMALL APERTURE ARRAY

We seek to gain a fuller understanding of seismic coda generation in the continental crust, by identifying secondary (scattering) sources illuminated by a distant primary source. We have developed a migration technique to scan seismic coda recorded by a small-aperture seismic array for phases generated locally by scattering from large heterogeneities, or topographic undulations. We use a widely distributed suite of seismic events to illuminate the local crustal volume from different directions and produce an image of the local crust. Stable apparent secondary seismic sources are observed, and interpreted as scatterers excited by the primary events.