Investigation of P Travel Time-Curve
Abstract
By using a large number of LRSM stations and a number of earthquakes from all azimuths and the well controlled nuclear explosions, a study of the 'P' travel-time curve reveals it to be nearly a series of straight-lines or legs throughout the total distance of about 105 degrees. Time as well as amplitude residuals were determined for the stations used and were found to be acceptably consistent. Analysis of the variance of the several modes of handling the data of each leg is shown which is significant in indicating the relative probability of each model as an explanation of the observed data. The 'F' statistic value, degrees of freedom, etc. are shown for each leg. The existence of real differences in 'P' travel-times and thus of mantle velocity structure are illustrated indicating that the velocity varies as a function of azimuth. The very close correlation between site geology and average noise level on signal amplitude is discussed as well as this effect on magnitude calculations. In addition, a computed 'B-factor' curve developed from this study is compared with Gutenberg's and one by Clawson of Geotech.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 29, 1969
- Accession Number
- AD0872607
Entities
People
- D. M. Clark
- J. F. Evernden
Organizations
- Teledyne Technologies