Detection Seismology: 1. Phase Reversal and Time Delay of Explosion-Generated Surface Waves. 2. Instrument Response of the Kongsberg VLP-System. 3. Unidentified Events Recorded by the Kongsberg VLP-System
Final scientific rept. 1 Apr 1972-31 Mar 1976
BERGEN UNIV (NORWAY) SEISMOLOGICAL OBSERVATORY
Pagination or Media Count:
A phase shift of 180 deg. has been found between the Rayleigh wave trains of two closely located Eastern Kazakh explosions. The Rayleigh waves from one of the explosions were delayed by about 4 sec relative to the Rayleigh waves from the other explosion. The event generating the delayed Rayleigh waves excited relatively strong Love waves, but these waves were not delayed. Various causes for the anomalies have been discussed - explosion-collapse pairs- depth differences and spallation. It seems that the Love waves of the anomalous event have been generated very near the source at the time of the detonation while the Rayleigh waves have been generated by a secondary event, -collapse - or by spall closure above the explosion.