Articles | Volume 7, issue 3
13 Jun 2007
13 Jun 2007

A test for checking earthquake aperiodicity estimates from small samples

M. Mucciarelli

Abstract. In recent years, many new models for earthquake recurrence were proposed. Some are focusing on the clustering properties on a small time scale, while others try to model the long term behavior of large mainshocks. To this last purpose, there is a growing interest for models that take into account the aperiodicity aiming to a time-dependent hazard estimate. It is well known that a limited number of inter-event times (IETs) may lead to biased values of the distribution parameters. To overcome this problem different solutions were proposed. This paper focuses on two of them: Monte Carlo simulation of the process and aperiodicity estimated via a statistical proxy. The topics discussed are: 1) how many IETs are needed for a correct estimate, 2) to which extent a Poisson distribution is equally able to describe the process, 3) the influence of errors associated to paleoseismological IETs, and 4) the goodness of the success ratio from simulations. A simple test is proposed to discriminate real aperiodicity from apparent aperiodicity coming from undersampling.