- Ground-motion model is (note that there is a typographical error in Kamiyama et al. (1992); Kamiyama (1995)
because r
_{t}has been replaced by r_{c}in equations):_{i}= 1 for i station, S_{0}= 0 otherwise, a_{max}is in cm∕s2, b_{1}= -1.164, b_{2}= 0.358, c_{a}= 2.91, r_{c}= 5.3km and σ = 0.247 (A_{i}given in publications but not reported here due to lack of space). - Instrument correct records and filter with pass band between 0.24 and 11Hz.
- Model individual soil conditions at each site as amplification factors, AMP
_{i}, as described by Kamiyama and Yanagisawa (1986). - Most records are from hypocentral distances between 30 and 200km.
- Focal depths between 0 and 130km.
- Models peak ground accelerations independent of magnitude and distance in a fault zone, r
_{t}, where r_{t}= r_{c}10^{(b1+b2M)∕1.64}. - Constrain decay with distance in far field to -1.64 using results from other studies to avoid problems due
to correlation between M and log
_{10}r. - Use trial and error method to find r
_{c}so that resulting values of r_{t}are consistent with empirical estimates of fault length from past studies. - Also give expression using shortest distance to fault plane (rupture distance), R, by replacing the expression
for r ≤ r
_{c}and r > r_{c}by one expression given by replacing r, hypocentral distance, by R+r_{c}in expression for r > r_{c}. This gives PGA independent of magnitude at distance R = 0km. - Note that use of r
_{hypo}is not necessarily best choice but use it due to simplicity. - Check residual plots; find no trends so conclude adequate from statistical point of view.