ISSN:
1420-9136
Keywords:
P-wave interference
;
Seismic array techniques
;
Velocity heterogeneities
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract The arrival at the Yellowknife Array (YKA) of closely-spaced P-waves having slightly different values ofdT/dΔ, azimuth, and amplitude has been simulated using synthetic 1 Hz wavelets. Adaptive-processing determinations of apparent slowness and azimuth show a remarkable pattern of fluctuations with time for varying separations of the interfering pulses. In the critical separation range 0.30 to 0.55 s, these fluctuations greatly exceed the differences in arrival vectors of the primary wavelets themselves. Observation of characteristic interference patterns on real array seismograms might permit the identification of triplications associated with radial velocity anomalies in the lower mantle. Processed YKA seismograms for three events at distances close to 90° are presented, which, despite apparently simple P onsets illustrate the pattern of drift indT/dΔ expected for such a triplication.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00876133
