Earthquake-induced ground acceleration

Abstract

Earthquakes may be characterized after the event by several physical parameters, including the linear dimension of the fault, l, and the stress drop, p. Although the direct measurement of these parameters is often difficult, there are data on the frequency distribution of l and p for certain series of earthquakes (refs 1–11; C. Archambeau, unpublished data; personal communications from T. Mikumo, T. Utsu and R. I. Archuleta). For p there is evidence^12–14 that the frequency distribution N(p) is given by a relationship of the form log N (p) = c₁−(1−α) log p (1) where c₁ and α are constants (α lying between 0 and 1) and N (p) dp is the number of stress drop in the range p to p + dp and p₁<p<p₂(p₁>0, where p₂ is limited). We report here that a relationship of this type holds (with specific parameters c_l and α) for 15 different sets of earthquake occurring in Japan, California, Mexico, Nevada, Italy and the Aleutian arc. We also show that the frequency distribution N(p) provides some information about the frequency distribution of ground acceleration during earthquakes.