Three earthquakes greater than seven Richter degrees (1985 with a magnitude of 8.1; 32 years later -in 2017- with 7.1 and the most recent in 2022 with 7.4) have shaken the Mexico City and the collective consent of the people who question “This September 19, will it tremble again?”
The similarities of the phenomena have also caused scientists to be asked what is the probability that a tremor in the pacific shores or in the inland mexico resented the capital of the country.
However, there is no way to predict an earthquake; in accordance with George Aguirre, of UNAM Engineering Institute, mentions that “Earthquakes cannot be predicted, we cannot say when an earthquake is going to occur, but neither are we going to be able to ensure that earthquakes will not occur.”IT MAY INTEREST YOU: AMLO reports death after earthquake in Michoacán; fence fell in Colima shopping center
Although it is believed that September is the month with the greatest presence of earthquakes, due to the mark left by the tragedies of 1985 and 2017, this is not the case; Arturo Iglesias Mendoza, head of the National Seismological Service, has mentioned that “if we are guided by the history of major earthquakes, we will realize on a broader scale, that the month with the greatest frequency is December”.
Being Warriornot Mexico City, one of the areas of the country with the greatest potential for telluric movements and tsunamis. This due to the famous seismic gap.
Xyoili Perez, teacher of the National Autonomous University of Mexico Y Diego Melgar, assistant professor of Geophysics at the University of Oregon published an article in the journal Geophysical Research Letters where they explain what happened with the 2017 earthquake.
The tremor with epicenter in Puebla-Morelos was different from most earthquakes, which occur in front of the pacific shores where two tectonic plates collide.
That is, the earthquake of 2017 went below the Cocos continental plate, causing it to break apart and are called bending earthquakes.
While the subducted plate located below the central part of the country has the potential to create earthquakes from Michoacan to Oaxaca.
The study indicates that the bend zone closest to the CDMX is found with an orientation between 20 and 30 degrees, so they mention that Another earthquake similar to the one in 2017 could occur in Cuernavaca.
In accordance with Mogens Bladtresearcher at Department of Probability and Statistics of the National Autonomous University of Mexico (UNAM), who was consulted by the media The country in 2017 – and although he stated that earthquakes occur randomly – stated that the probability that they occur on the same date as a previous one is exactly the same.
Bladt’s explanation is as follows: if “p” is the probability that an earthquake occurs on any given day and we assume that it is the same for every day of any year is: q= 1-(1-p)^nwhere “n” is the number of years elapsed.
Pérez mentioned at the time, five years ago, that between January 1, 1985 and September 18, 2017 there had been five tremors greater than seven Richter degrees in Mexico City; however, in an investigation through the website of the National Seismological Service, we found that since September 19, 2017, four more movements have been registered.
Giving a total of 9 earthquakes greater than 7 degrees in the last 37 years. These are: September 19, 1985, September 20, 1985, June 15, 1999, March 10, 2012, April 18, 2014, September 19, 2017, February 16, 2018, June 23, 2020 and December 7, September 2021.
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So in 37 years they are 13 thousand 514 days (counting the leap years of 1988, 1992, 1996, 2000, 2004, 2008, 2012, 2016, and 2020), with 9 major earthquakes at seven degrees in CDMX the probability would be q= 1-(1-9/13514)^37= 0.0243= 2.43% (according to the same calculations made by El País).
In his time, Bladt clarified that “It is not such a small probability, perhaps much less than many would have expected.”
Meanwhile in Twitter It has also emerged that the probability of an earthquake on September 19 is 0.000751%, These calculations with UNAM physicist, José Luis Mateos, who explained that the possibility is 1 in 133 thousand 225 casesexpressed in the previous percentage.
That is, the probability that an earthquake will happen again September 19th is little, but never zero.