Interpretation of Strong-Motion Earthquake Accelerograms: The Bear Valley Event of 1973
TEXAS INSTRUMENTS INC DALLAS EQUIPMENT GROUP
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The solutions to eight earthquakes have been obtained from near-field strong-motion accelerograms using Haskells moving dislocation source model. In particular, the solutions to the San Fernando main shock and three small aftershocks were re-examined using the corrected orientation of the Pacoima Dam instruments. A reasonable match to the observed waveforms for the main event could only be obtained by having a large strikeslip dislocation component on the deeper segments of the fault. Also, new locations and orientations were obtained for the three small aftershocks. Using both Haskells model and spectral analysis, the Bear Valley earthquake of June 22, 1973 was examined. Both approaches yielded substantially the same results a large dislocation on the order of 100 cm over a small fault area of less than 1.0 sq km, with a seismic moment Mo of 1.2 to 1.5 x 10 to the 25th power dyne-cm.
- Seismic Detection and Detectors