2013 Volume 1 Issue 1 Pages 262-275
The instrumental seismic intensity of Japan Meteorological Agency (JMA) uses three types of filters which consist of high-cut, low-cut and period functions. An extended function of the low-cut filter is used to evaluate the effect of long-period range on seismic intensity in the paper. An asymptotic filter processing of acceleration in the extended function is proposed to express seismic intensities corresponding to velocity and displacement. The seismic intensity level using the running r.m.s. method is applied to clarify the effects of various frequency-weighted accelerations on seismic intensity. The seismic intensity levels corresponding to velocity and displacement are also discussed and compared with intensities of spectral characteristics.