A new expression for the earthquake interevent time distribution

The distribution of interevent times between two successive earthquakes is generally modelled as Gamma distribution. However, significant deviations from Gamma distribution have been observed at small interevent times. These deviations can be easily modelled through the introduction of a new parameter in the interevent time distribution. The log-likelihood estimations of the model parameters performed for the data from four earthquake catalogues reveal that the proposed model fits the data well. Finally, the new parameter is interpreted in terms of the c parameter of the Omori law.