MAGNITUDE STUDIES CONDUCTED UNDER PROJECTS VT/5054 AND VT/5055.
Abstract
Station magnitude corrections are developed and the possibility of azimuthal dependence of station correction is investigated by means of a statistical model for Blue Mountains Seismological Observatory, Cumberland Plateau Seismological Observatory, Tonto Forest Seismological Observatory, Uinta Basin Seismological Observatory, and Wichita Mountains Seismological Observatory. Azimuthal dependence of station correction is not established at any of the observatories. Refined distance-depth magnitude correction factors are developed for epicentral distances between 20 degrees and 90 degrees for depths between 50 kilometers and 200 kilometers and for distances between 0 degrees and 110 degrees for depths less than 50 kilometers. Existing distance-depth correction factors are found to be too large for distances less than 15 degrees and too small for distances greater than 100 degrees for depths less than 50 kilometers. Station magnitude corrections are also developed from magnitude frequency distributions and are found to agree within 0.06 magnitude unit with station corrections determined from the statistical model. The mean observatory magnitude, computed both as the arithmetic mean of observatory magnitudes and as the logarithm of the arithmetic mean of observatory normalized amplitudes, is compared to the USC+GS magnitude.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 20, 1966
- Accession Number
- AD0803337
Entities
People
- Jack G. Swanson
Organizations
- Geotech Instruments (United States)