Home > Issues & Journals

ESTIMATION OF FOCAL PARAMETERS FOR UTTARKASHI EARTHQUAKE USING PEAK GROUND HORIZONTAL ACCELERATIONS

A. Paul, M. L. Sharma and V. N. Smgh .

Paper No.: 372

|

Vol.: 35

|

No.: 1-3

|

September, 1998

|

pp. 1-8

Abstract

 

The focal parameters of Uttarkashi earthquake of October 19, 1991 ( M, 7.00, mb 6.5) have been estimated using strong ground motion data. The fault plane parameters namely, dip, strike and slip angle are estimated using high frequency radiation in the form of peak ground accelerations at near distances. The observed radiation pattern is obtained using the peak ground accelerations in the azimuthal direction of the stations. The observed radiation pattern is then compared with the theoretically computed radiation pattern for S waves for different values of focal parameters. The focal parameters estimated by minimizing the error between observed and theoretically computed radiation patterns are: strike – N 315°, dip – 14°, and slip angle – 144°. The results obtained using strong ground motion data are compared with the fault plane solutions computed using comparatively long period waves reported by various agencies. The matching of results obtained in the near field and the far field show that the rupture over the fault plane may not have too much of scatter in different parts.
Keywords: Radiatton pattern, strong motion data., focal parameters, Uttarkashi earthquake

©2025. ISET. All Rights Reserved.