On the Relation between the Predominant Period and the Maximum Amplitude of Earthquake-Motions

Abstract

The frequency distribution of the max. amplitude, α, and the max, acceleration, α, at a station is expressed by N(α)da=ka^-mda and N(α)dα=k′α^-m′dα, respectively. A relation, m′=(m-1/q+1), holds between m and m′, q being defined by the formula α=coast. α^q. The predominant period of earthquake motions T can be calculated according to the above mentioned relation, as we have α=(2π/T)²α, or T=const α^1-q/2. The observed values at Hongo, Tokyo are as follows,
m=1.74, m′=2.12, q=0.66, and T=const. α^0.17.