@article{epos1367,
          volume = {112},
          number = {B2},
           month = {February},
          author = {Anna Maria Lombardi and Warner Marzocchi},
           title = {Evidence of clustering and nonstationarity in the time distribution of large worldwide earthquakes},
       publisher = {American Geophysical Union},
            year = {2007},
         journal = {Journal of Geophysical Research},
           pages = {313--320},
             url = {https://episodesplatform.eu/eprints/1367/},
        abstract = {The purpose of this paper is to characterize the statistical distribution of worldwide
largest earthquakes. We analyze the distribution of worldwide shallow events with
M s 7.0+ since 1900, by following the Occam?s razor philosophy; we start from the
simplest possible model (stationary Poisson process), and we inspect more complicated
models only if the data show significant departures from the simplest one. The results
show two important characteristics; first, worldwide M s 7.0+ earthquakes tend to cluster in
time and space, with features similar to smaller events. Second, for some seismic
regions there is evidence in favor of long-term fluctuations of the earthquake rate. These
results support the hypothesis of universality, suggesting that an ETAS model with a
background varying with time can be considered reliable to describe the seismicity
distribution over a wide space-time-magnitude window. From a practical point of view,
our findings suggest that the paradigm that seismic zones are stationary systems, implicitly
assumed in seismic hazard assessment, should be regarded with caution.}
}