Journal of Natural Disaster Science
Journal of Natural Disaster Science, Volume 2, Number 1, 1980, pp.1f.
SURFACE DISTURBANCES DUE TO A DISLOCATION SOURCE IN A MULTI-LAYERED MEDIUM −DISTURBANCES AT TOKYO DUE TO A HYPOTHETICAL TOKAI EARTHQUAKE−
(Received 27 July, 1980, and in revised form 1 October, 1980)
Abstract
Investigations into the surface disturbance associated with an earthquake have commonly based on the conception of body waves. New formulations are derived to seismograms inclusive of dispersive surface waves due to a dislocation source model in a multi-layered medium. It is known that high-frequency components are excluded from the theoretical seismograms. From the analysis of strong-motion accelerograms, empirical relations are established thereby estimate the maximum amplitudes for the case wherein short waves are included. Upon combining theoretical formulations with the empirical relations mentioned above, the maximums of surface displacements, velocities and accelerations at Tokyo metropolis are estimated. These magnitudes might probably be realized by us in a Tokai earthquake in the future. As an overall average, the maximums so predicted are 38 cm in displacement, 53 kine in velocity, and 280 gal in acceleration, which appear in the surface-wave portions of seismograms.