Console, Rodolfo and Murru, Maura (2001) A simple and testable model for earthquake clustering. Journal of Geophysical Research, 106 (B5). pp. 8699-8711.
Full text not available from this repository.Abstract
Earthquakes are regarded as the realization of a point process modeled by a gener- alized Poisson distribution. We assume that the Gutenberg-Richter law describes the magni- tude distribution of all the earthquakes in a sample, with a constant b value. We model the oc- currence rate density of earthquakes in space and time as the sum of two terms, one repre- senting the independent, or spontaneous, activity and the other representing the activity in- duced by previous earthquakes. The first term depends only on space and is modeled by a continuous function of the geometrical coordinates, obtained by smoothing the discrete distri- bution of the past instrumental seismicity. The second term also depends on time, and it is factorized in two terms that depend on the space distance (according to an isotropic normal distribution) and on the time difference (according to the generalized Omori law), respec- tively, from the past earthquakes. Knowing the expected rate density, the likelihood of any re- alization of the process (actually represented by an earthquake catalog) can be computed straightforwardly. This algorithm was used in two ways: (1) during the learning phase, for the maximum likelihood estimate of the few free parameters of the model, and (2) for hypothesis testing. For the learning phase we used the catalog of Italian seismicity (M ≥ 3.5) from May 1976 to December 1998. The model was tested on a new and independent data set (January- December 1999). We demonstrated for this short time period that in the Italian region this time-dependent model has a significantly better performance than a stationary Poisson model, even if its likelihood is computed excluding the obvious component of main shock-aftershock interaction.
| Item Type: | Article |
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| Subjects: | Methodology > Method and procesing > Collective properties of seismicity > Clustering and migration |
| Project: | IS-EPOS project |