MULTICOMPONENT STRAIN SEISMOGRAPH
Abstract
Use of an electromagnetic calibrator in place of the magnetostrictive calibrator on the vertical strain seismometer has eliminated phase discrepancies. Results show that all strain and inertial systems are matched within 4 degrees between 0.1 and 3 cps and within 10 degrees out to 10 cps. An analysis of coherency, phase, and spectra of seismic noise and signals computed by a fast transform BLACKY program shows that the instruments are operating according to theory. Comments relating to the character of the seismic noise are also given. The effects of temperature changes and wind on operation of the horizontal strain seismometers are discussed. Operation of a matched long-period horizontal strain-inertial combination for directional discrimination of long- period surface waves is also discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 18, 1967
- Accession Number
- AD0819611
Entities
People
- B. W. Girard
- J. R. Sherwin
- R. C. Shopland
- R. H. Kirkland
Organizations
- Geotech Instruments (United States)