Accession Number : ADA305459

Title :   Lg Excitation, Attenuation and Source Spectral Scaling In Central Asia and China.

Descriptive Note : Final rept. 1 Nov 93-31 Oct 95,

Corporate Author : SAINT LOUIS UNIV MO DEPT OF EARTH AND ATMOSPHERIC SCIENCES

Personal Author(s) : Xie, J. ; Cong, L. ; Mitchell, B. J.

PDF Url : ADA305459

Report Date : 05 JAN 1996

Pagination or Media Count : 34

Abstract : The nonlinear inverse method of Xie (1993) is applied to analyze Lg spectra from 21 underground nuclear explosions and 52 shallow (5-33 km) earthquakes in central Eurasia where, for numerous paths, Lg Q and Lg coda Q at 1 Hz are found to be very similar. The logarithm of Lg seismic moment (Mo) values correlate linearly with body wave magnitude (Mb), with slopes of slightly greater than 1.0. For the same Mo values, the Mb values for earthquakes tend to be systematically lower than those for explosions. For both explosions and earthquakes, Mo scale with fcaa, with fc being Lg corner frequency and a being closer to 4 than to 3. For explosions, the estimated Mo, fc values are dependent on whether the explosion or earthquake source model is used. At any given Mo level, the fc value estimated for an explosion with the earthquake source model tends to be higher than that for an earthquake. This tendency appears to be opposite to that observed at the NTS, and maybe used as an explosion discriminant for central Eurasia.

Descriptors :   *UNDERGROUND EXPLOSIONS, *NUCLEAR EXPLOSION DETECTION, *SEISMIC DISCRIMINATION, *EARTHQUAKES, NONLINEAR SYSTEMS, SCALING FACTOR, SEISMIC WAVES, ATTENUATION, INVERSION, EURASIA, ASIA.

Subject Categories : Seismology
      Seismic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE