A total of 570 earthquakes were recorded in the State of Jalisco between January 1 to September 15 of this year, a statistic that is within the normal range for the state, according to the Seismological System National.
As for the magnitude, the highest that has been recorded this year was 5.8, during the earthquake of May 31 at noon with epicenter in Cihuatlán, 8 kilometers deep, which did not cause infrastructure damage. Those that followed have been substantially smaller, with a magnitude of 4.6, and also in Cihuatlán.
Of the 570 telluric movements that have occurred so far this year, 301 were generated in the territory of Cihuatlán in the South Coast, that is, 52.8 percent of the total tremors in Jalisco, of which the majority are of low intensity. This area is followed by the North Coast, with 15 percent of the events reported in the area of Puerto Vallarta.
According to the geological configuration of the region, Mexico is at the confluence of five tectonic plates and one of them, Rivera, is in subduction between Jalisco and Colima, that is, it is submerged under both territories, which causes the recurring earthquakes, although of low magnitude.
Because in the country there are only measurements of the telluric movements of 225 years to date, the National Seismological System does not have enough information to determine how often larger events occur in the area, nor what magnitude they can reach.
Throughout the subduction zone, there is a record of an earthquake that reached a magnitude of 8.2. This occurred in 1932 and covered the coasts of Jalisco and Colima, with a length of 230 kilometers. The next largest earthquake was that of 1985, on the coast of Michoacán, which had a magnitude of 8.1.
The large earthquake in Japan during 2011 is believed to happen around every thousand years based on statistics from that country. So if we take into account the 225 years of seismic history that we know for Mexico, the magnitude would be limited to 8.6, but we do not know if there was something much longer prior to record-keeping, so studies of paleosismology and coupling between plates are needed to have better estimates, not predictions, about future events.