Source parameters of the June 29, 1992 Little Skull Mountain Earthquake from complete regional waveforms at a single station

The June 29, 1992, m{sub b} = 5.5, Little Skull Mountain earthquake occurred 20 km southeast of Yucca Mountain within the boundaries of the Nevada Test Site. This event was recorded at a very broadband station located about 310 km to the east at Kanab, Utah. Both body and surface waves from this single station were used in a grid search technique for the best fitting double couple moment tensor. The technique minimizes the misfit between reflectivity generated complete synthetic seismograms and the three-component displacement data via a search over the strike, dip and rake of the source. In the passband of 50-15 s period, the grid search results in a well defined, nearly pure normal mechanism with a strike of 35{degrees}, a dip of 54{degrees}, a rake of {minus}87{degrees}, and a seismic moment of 4.1 x 10{sup 17} N-m. Applying the same technique to the large aftershock on July 5, 1992 the authors obtain a somewhat less well defined minimum with a strike of 358{degrees}, a dip of 36{degrees}, a rake of {minus}177{degrees}, and a moment of 4.3 x 10{sup 15} N-m. The minimum-compression axes of these mechanisms are consistent with northwest-southeast extension in the Basin and Range. 14more » refs., 7 figs.« less

[1]  G. Mueller,et al.  The reflectivity method; a tutorial , 1985 .

[2]  A. Dziewoński,et al.  Single station CMT; Application to the Michoacan, Mexico, Earthquake of September 19, 1985 , 1986 .

[3]  M. Cara,et al.  Focal mechanisms of moderate-size earthquakes from the analysis of single-station three-component surface-wave records , 1989 .

[4]  W. Rodi,et al.  Crustal structures inferred from Rayleigh-wave signatures of NTS explosions , 1978 .

[5]  Howard J. Patton,et al.  Q structure of the Basin and Range from surface waves , 1984 .

[6]  H. J. Patton,et al.  Seismic Moment tensors of western U.S. earthquakes and implications for the tectonic stress field , 1991 .

[7]  M. Wyss,et al.  Inversion of source parameters for subcrustal earthquakes in the Hellenic Arc , 1990 .

[8]  John H. Woodhouse,et al.  Determination of earthquake source parameters from waveform data for studies of global and regional seismicity , 1981 .

[9]  Howard J. Patton,et al.  Measurements of Rayleigh-wave phase velocities in Nevada: Implications for explosion sources and the Massachusetts Mountain earthquake , 1982 .

[10]  L. A. Wright.  Late Cenozoic fault patterns and stress fields in the Great Basin and westward displacement of the Sierra Nevada block , 1976 .

[11]  T. Wallace,et al.  The determination of source parameters for small earthquakes from a single, very broadband seismic station , 1991 .

[12]  H. Patton.  Source models of the Harzer explosion from regional observations of fundamental-mode and higher mode surface waves , 1988 .

[13]  Douglas S. Dreger,et al.  Source parameters of the Sierra Madre Earthquake from regional and local body waves , 1991 .