Journal of Natural Disaster Science
Journal of Natural Disaster Science, Volume 11, Number 2, 1989, pp.21f.
ESTIMATION OF SEISMIC INTENSITY OF GROUND MOTION DURING THE 21 AUGUST 1988 EARTHQUAKE IN THE NEPAL-INDIA BORDER REGION
(Received 10 October, 1989 and in revised form 20 December, 1989)
Abstract
No strong motion acceleroghaphs were available for areas 70 to 80 kilometers from the epicenter of the August 1988 Nepal-India earthquake. We therefore calculated the theoretical distribution of the maximum accelerations in the region near the earthquake source. A simplified analytical procedure with which to estimate the attenuation of peak ground motion was developed that takes into account the fault extent. Peak acceleration near the fault region is expressed as a function of the fault parameters and the relative collocation between the fault and the observation site. The peak acceleration at bed rock level first was estimated, then the damping effect of the path traveled and the amplification factor of the surface ground were introduced. The estimated distribution of ground motion intensity was com-pared with the data from a distribution questionnaire. In addition, the maximum accelerations at places where liquefaction occurred during the earthquake were estimated from the results of laboratory tests done on collected sand specimens.
Key words
Nepal-India border earthquake, ground motion intensity, source mechanism, liquefaction