Accession Number : AD0446223


Title :   A COMPARATIVE STUDY OF THE SHOAL EVENT,


Corporate Author : UNITED ELECTRODYNAMICS INC ALEXANDRIA VA


Personal Author(s) : Nostrand, Robert Van ; Helterbran, Wayne


Report Date : 29 Aug 1964


Pagination or Media Count : 1


Abstract : The SHOAL explosion was a part of Project SHADE of the VELA-UNIFORM program to determine characteristic differences between seismic signals recorded from nuclear explosions and earthquakes. The FALLON earthquake occured at moderate depth along the fault zone separating the Sand Springs and Stillwater Ranges from the Fairview and Dixie valleys. The SHOAL explosion was detonated in the granite outcrop area slightly over 40 kilometers southwest of the Fallon epicenter. This choice not only facilitated comparison with the nearby earthquake of comparable magnitude but also with the HARDHAT explosion, also of comparable magnitude, detonated in granite at NTS farther south. Summary descriptions of SHOAL, FALLON, and HARDHAT are given in Table 1. There are a number of characteristic differences previously observed for explosions and earthquakes at different locations recorded at relatively small distances. These same differences are quite apparent for the SHOAL and FALLON events occuring near the same location. In both cases, there is substantially more energy apparent in the compressional waves from SHOAL and in the shear waves from FALLON. Differences in separation of the phases Pn, Pg, and Lg for SHOAL occurring at the surface and FALLON occurring at a depth of a few kilometers are also apparent. (Author)


Descriptors :   *NUCLEAR EXPLOSIONS , *SEISMIC WAVES , EARTHQUAKES , FAULTS(GEOLOGY) , SIGNALS , GRANITE , SEISMOGRAPHS , WAVE PROPAGATION , TABLES(DATA) , MEASUREMENT , SEISMOLOGICAL STATIONS , INTENSITY


Distribution Statement : APPROVED FOR PUBLIC RELEASE