Earthquake Three-Peat in Mexico

On Monday Sep. 19, the Mexican Seismic Alert System (Sistema de Alerta Sísmica Mexicano or SASMEX) team tested newly installed earthquake alarms throughout central and southern Mexico. SASMEX conducts tests of their alert system annually to ensure that individuals within the vicinity of the alarm can hear it in case of an actual earthquake. 

SASMEX planned to test the new alarms Monday afternoon and notified citizens so they would be prepared for the drill, but when the alarms sounded in the morning, the team knew something was wrong. 

The alarms sounded just before noon on Monday, prompting multiple citizens out of their homes. Moments after the alarm sounded, a 7.6 magnitude earthquake hit the city of Michoacan, right outside the city of Guadalajara in southwest Mexico. 

This is the third time Mexico has endured an earthquake on Sep. 19, the first being in 1985 which killed over 5,000 civilians, and the second in 2017 killing around 350. 

There were two reported deaths after Monday’s earthquake. According to NBC, a woman died after getting caught under falling structures near Manzanillo and there have been no details reported on the second death. There were also reports of damage to many buildings and cars due to the rumbling.

Due to the high magnitude of the earthquake and it hitting the coast of Mexico, tsunami warnings were issued and encouraged people to get to high ground. There have been no tsunami waves reported.

According to the LA Times there has been speculation by the citizens of Mexico deeming that day cursed in Mexican history. This incident has a lot of people wondering if there is any correlation between September 19th and earthquakes in Mexico, seeing that this is the third time it has happened in forty years.

Point Loma Nazarene University biology professor Walter Cho shared his perspective on the deemed “cursed” day.

“Earthquakes are basically a release of energy between tectonic plates that make up the surface of the earth, so the fact that you have three earthquakes in the same place on the same day across forty years is really just a coincidence,” Cho said.

Cho also touched on how it is possible that some individuals, especially those living in areas of frequent seismic activity, may have gotten a little too comfortable due to the lack of earthquakes in recent years. 

“It is possible that people may have become complacent, you know, everyone talks about the big one [earthquake] that’s supposed to come but, according to models, it’s overdue, there is this build up of energy that will probably be released at some point,” Cho said.

Although there is worry about that energy being released soon, Cho brought up the factor of geological time scales.

“One year, 10 years, 100 years, it’s all so small because it’s a really long time scale so it could really happen at any point and we don’t really know yet. We do have early warning systems that try to let us know which is built up by the US Geological Survey, and these systems try to get that information to us like the new alert system did in Mexico,” Cho said.

With San Diego being the city with the largest fault line in California, there are certain things citizens should be aware of in case an earthquake does occur.

“Where we live, because we are on the coast, the other associated threat that comes with earthquakes is tsunamis, which are massive waves formed by displacement in the ocean, often caused by quakes in which the best effort of finding safety would be to get away from the coast and to get up high,” Cho said.