SHORT PERIOD MICROSEISMIC STUDY AT SKULL CLIFF, ALASKA.

• Main Authors: Olson,James J., Mooney,Harold M.
• Other Authors: MINNESOTA UNIV MINNEAPOLIS
• Format: Text
• Language: English
• Published: 1964
• Subjects: (*MICROSEISMS; ALASKA); (*ALASKA; SEISMOLOGY); GEOPHYSICS; NOISE; BACKGROUND; FREQUENCY ANALYZERS; SEISMIC WAVES; Arctic; Alaska
• Online Access: http://www.dtic.mil/docs/citations/AD0600254; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0600254

Seismic background noise was measured at a location on the Arctic coast of Alaska. Continuous high-speed records were obtained with calibrated amplitudes. Frequency response extended from 1 to 100 cps (.01 to 1 second periods). The records were digitized in order to compute power spectra. The most striking result was the existence of a spectral peak at approximately 12 cps (.07 to .12 second period). Maximum amplitudes of ground vibration correlated well with ocean surf activity, as well as with barometric lows, maximum wave heights, and maximum wind velocities. Amplitudes differed by a factor of 10 between conditions of quiet and active surf, with peak-to-peak ground displacements of the order 0.01 and 0.1 microns, respectively. The shape of the power spectra and the position (on the frequency scale) of the spectral peak were largely independent of surf activity and the other factors noted above. (Author)