Discrimination Using Pn and Pg
Abstract
Two regional discriminants are being developed and tested on western U.S. data bases. The first is based on the observation that the onset of the Pn waveform is stable in character and typically much different than most earthquake Pn waveforms. The results were reasonably consistent between stations. The average waveform at a fixed station is exceptionally consistent between the Pahute Mesa and Yucca test sites indicating that average Pn waveform is a stable function of time. Synthetics were computed both on the assumption that high frequency Pn is a turning ray in a smooth positive gradient in the lid and also that it is a true head wave. Effective pP is later than elastic time as is usually observed. This simple reflection and probably involves-spall. A set of earthquake Pn waveforms from the digital stations was collected. Earthquakes could be discriminated from explosions on the basis of the correlation of the Pn waveform with the average explosion Pn. The second discriminant is being developed around the Pg waveform. A suite of explosion Pg's was averaged to find which of its characteristics are most stable. Seismic Discrimination.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 1988
- Accession Number
- ADA202018
Entities
People
- C. K. Saikia
- L. J. Burdick
- N. F. Smith