Why are there so many earthquakes in Mexico?

According to the National Seismological Service, five tectonic plates interact in Mexico: North America, Cocos, Pacific, Rivera and the Plate of the Caribbean

This Friday, another earthquake, of magnitude 5.2, hit Mexico. While the authorities reported that there were no injuries and that there was no need for a tsunami warning, many in the country are on edge due to the seismic events this week.

So far, the SSN (National Seismological Service) reported that there have been 1,650 aftershocks of the magnitude 7.7 earthquake that occurred on 19 September, the largest of which occured at dawn on 22 September. And now, this Friday’s earthquake has been added to the list.

The SSC-CDMX (Secretariat of Citizen Security of Mexico City) reported that, after the activation of the seismic alert in the country’s capital, a woman lost her life when she hit her head falling down stairs at her home, located in the Doctores neighborhood, in the Cuauhtémoc district. A man suffered a fatal heart attack upon hearing the earthquake alarm, according to local authorities.

Why are there so many earthquakes in Mexico right now?

According to the SSN, five tectonic plates interact in the Mexican Republic: the North American, Cocos, Pacific, Rivera and Caribbean plates. This caused, at least in 2017 after the earthquake of September 19 of that year, a total of 15,400 telluric movements.

SSN experts have reported that when two tectonic plates meet, they release a large amount of stress that can deform the earth’s crust and, for their evaluation, require the use of suitable instruments to measure their impact.

The magnitude 7.1 earthquake that occurred on September 19, 2017, which left 370 dead and 7,289 injured, was caused because the Cocos plate settled below the North American and, when the material of that plate generated sudden movements on the surface, experts say.

Each tectonic plate has its own movement and is constant. While in the northern part of Mexico, they move at a rate of three centimetres per year, in the south, this speed can reach seven centimetres per year. That would explain the high seismicity in states like Chiapas and Oaxaca.

According to SSN estimates, from January 1990 to September 2017, more than 86,000 earthquakes have been recorded in Mexico. Per day, 15 telluric movements of less than two degrees of magnitude are recorded.

Measurement systems have achieved greater precision in measuring these phenomena. Although 796 earthquakes were recorded in 1990 and 15,281 in 2016, this is mostly nothing to worry about, experts say.