Moho reflectivity and seismic signal penetration

Abstract

Analysis of amplitude decay and frequency change is applied to determine limits of seismic signal penetration on deep seismic reflection data collected by LITHOPROBE and the Consortium for Continental Reflection Profiling (COCORP). Changes in spectral frequency content are efficiently monitored with averaged instantaneous frequency and bandwidth. Results from Montana show pronounced increases in average frequency and slight drops in amplitude associated with a die-out of reflections at the Moho. Results from Quebec show amplitude and frequency change occurring through the Moho on lines with and without Moho reflections. These contrasting observations confirm both adequate signal penetration and that the differences in Moho reflectivity are representative of geologic differences.