Average P and PKP Codas for Earthquakes (118-180 degrees).
Abstract
The report presents results of analysis of 87 seismograms from small events (m sub b) = or < 5.8) recorded at 21 world-wide stations, 8 LRSM stations, and 3 observatories, and of 112 large-event ((m sub b), (M sub s), or secondary (m sub b) = or > 7.0) seismograms recorded at 34 world-wide stations, 10 LRSM stations, and one observatory. These results, together with other coda data previously reported, confirm previous conclusions that the greater the event magnitude, the higher is the relative amplitude level for elapsed times greater than about 20 seconds into the coda. The mean difference between large-event and small-event codas in the distance interval 42-180 degrees is 0.16 (m sub b) units. Because relative coda level at a given time after arrival onset is a function of magnitude, at least two sets of coda determinations are required, one each for large and small events in distance intervals specified between 118 and 180 degrees.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 28, 1974
- Accession Number
- ADA011361
Entities
People
- E. I. Sweetser
- T. J. Cohen