Bayesian analysis of the local intensity attenuation

Abstract

We present a method that allows us to incorporate additional information from the historical earthquake felt reports in the probability estimation of local intensity attenuation. The approach is based on two ideas: a) standard intensity versus epicentral distance relationships constitute an unnecessary lter between observations and estimates; and b) the intensity decay process is a ected by many, scarcely known elements; hence intensity decay should be treated as a random variable as is the macroseismic intensity. The observations related to earthquakes with their epicenter outside the area concerned, but belonging to homogeneous zones, are used as prior knowledge of the phenomenon, while the data points of events inside the area are used to update the estimates through the posterior means of the quantities involved.