On the correlation between solar activity and large earthquakes worldwide

Large earthquakes occurring worldwide have long been recognised to be non Poisson distributed, so involving some large scale correlation mechanism, which could be internal or external to the Earth. Till now, no statistically significant correlation of the global seismicity with one of the possible mechanisms has been demonstrated yet. In this paper, we analyse 20 years of proton density and velocity data, as reported by the ISC-GEM catalogue. We found clear correlation between proton density and the occurrence of large earthquakes (M>5.8), with a time shift of one day. The significance of such correlation is very high, with probability to be wrong less than 10-5. The correlation increases with the magnitude threshold of the seismic catalogue. A tentative model explaining such a correlation is also proposed, in terms of the reverse piezoelectric effect induced by the applied electric field. This result opens new perspectives in seismological interpretations, as well as in earthquake forecast.