- © 1996 by the Seismological Society of America
Stacking is a technique that combines large numbers of seismograms with different source-receiver geometries into a single composite image that typically has better signal-to-noise ratios than the individual records. This method has been routinely used by the oil industry for some time to image crustal structure from digital waveform data obtained using controlled source experiments. The increased availability of digital recordings of earthquakes from both local and global networks has made it possible to apply the stacking approach to studies of deep Earth structure. Walck and Clayton (1984) combined short-period vertical records from the Southern California Seismic Network to obtain upper-mantle velocity structure. Similarly, Vidale and Benz (1993) used vertical short-period records from seismic networks in the western United States to image upper-mantle discontinuities in the vicinity of deep earthquakes. Stacks of long-period Global Digital Seismograph Network seismograms have been used to image global body- and surface-wave phases (Shearer,...