Accession Number : AD0693340

Title :   INVESTIGATION OF PKP SEISMIC WAVES.

Descriptive Note : Annual rept. 1 Feb 67-15 Mar 69,

Corporate Author : STANFORD RESEARCH INST MENLO PARK CALIF

Personal Author(s) : Isherwood,William F.

Report Date : 15 MAR 1969

Pagination or Media Count : 113

Abstract : A four-element seismic array was established at Byrd Station, Antarctica, for investigation of PKP seismic waves. This seismic station (BYA) has been operating continuously since January 18, 1968. Seismic data are recorded on magnetic tape at a level permitting playback at a system magnification of as high as 500,000. Background ground motion amplitudes at Byrd Station were found to be in the order of 10 millimicrons at the outlying seismometers and frequently of the order of 100 millimicrons at the center seismometer when heavy equipment was operating, nearby. About 2,700 compressional and shear arrivals were reported in the first 8 months of recording, with epicenters ranging over the entire earth. About 400 of these events have been confirmed as PKP arrivals. The epicentral distance for these arrivals ranged from 100 to 173 degrees, with the majority being from the Japanese and Kurile areas. Data from the first full year of operation are now being processed at SRI. The station was turned over to the USC+GS and is currently being operated by that agency. (Author)

Descriptors :   (*SEISMOLOGICAL STATIONS, ANTARCTIC REGIONS), (*EARTHQUAKES, DETECTION), SEISMOMETERS, PHASED ARRAYS, EPICENTERS, SEISMIC WAVES, INSTRUMENTATION, CALIBRATION, DATA PROCESSING, MAGNETIC TAPE

Subject Categories : Seismology
      Seismic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE