Spectral analyses of high-frequency Pa Sn phases from very shallow focus earthquakes
Abstract
Hydrophone recordings from July 1979 through November 1980 have been examined for mantle-refracted P phases from underground nuclear explosions and from earthquakes at comparable distances. Explosion generated P phases are found to have a lack of energy relative to earthquake generated P phases for frequencies below about 1.3 Hz. Corner frequencies for explosion P's appear to be around 2 Hz while for earthquake P's these frequencies are lower than 1 Hz. Average amplitudes for explosion P's are higher than for earthquake P's for all recorded frequencies above 2 Hz, in spite of the fact that the average explosion magnitude is less than average earthquake magnitude. In the 2.5 to 2.9 Hz range explosion P's are at least 6 db higher than earthquake P's.
- Publication:
-
Interim Technical Report
- Pub Date:
- November 1980
- Bibcode:
- 1980uhi..rept.....W
- Keywords:
-
- Elastic Waves;
- Hydrophones;
- Ocean Bottom;
- Seismic Waves;
- Spectrum Analysis;
- Underground Explosions;
- Earthquakes;
- Nuclear Explosions;
- Pacific Ocean;
- Geophysics