How did you arrive at that number?
If both earthquakes (the one in 2017 and the one in 2022) are extraneous events, which is valid to assume because exactly 5 years passed between the previous tremor and the last one, then there is no influence of the first on the second date.
“It cannot be said that one event has induced the other, they are totally independent events in time”, explains Mateos.
In addition, they occurred in different areas of the country: the earthquake of September 19, 2017 had Puebla as its epicenter, south of the Valley of Mexico, while the epicenter of the earthquake of September 19, 2022 was on the coast of Michoacán.
“From the above we can conclude that there is no spatial correlation either,” says Mateos.
So, remembering that they are independent events, the laws of mathematics say that to know the probability of the coincidence happening, you must calculate the probability that one event occurs and then multiply by the probability that the other occurs.
“The probability of an earthquake occurring on a given date is 1/365, because the year has 365 days; and then by multiplying 1/365 by 1/365, the result is 1/133225, which is an estimate, under the assumption that there are earthquakes once a year, with an approximate magnitude of 7”, says Mateos.
That probability of 1/133225 is equivalent to winning the prize of a raffle where there are 133 thousand 225 tickets; in decimal terms, it is equal to 0.000751%, a number that has become viral on Twitter.
What are the chances that three earthquakes of more than 7 degrees will be registered in a country in three September 19? According to José Luis Mateos, @jlmateos, specialist in complex systems of the Institute of Physics of the UNAM, one for 133,225. Expressed another way, 0.000751%.
– Sergio Sarmiento (@SergioSarmiento)
September 19, 2022
To the question of what would be the probability that it would tremble again on September 19, 2023?, Mateos answers the following:
“It would be necessary to multiply that 1/133225 by 1/365 again. The result is 1/48,627,125, a very small number”, comments Mateos.
So it would be like winning the first prize in a lottery of 48 million 627 thousand 125 tickets. Which is very difficult, but not impossible.