Earthquakes on September 19 are just coincidence: US

José Díaz Briseño / Reforma Agency

Monday, September 19, 2022 | 20:12

Washington.- The fact that three major earthquakes in Mexico occurred on September 19 in different years -including this Monday- is just a coincidence and does not indicate that the country is more prone to these phenomena this month, said the Geological Service of United States (USGS).

According to a preliminary analysis of today’s event, the USGS pointed out that the earthquake is consistent with the effect produced by the collision of the Cocos tectonic plate with the North American tectonic plate in the area known as the zone of Mesoamerican subduction.

“Earthquakes are a common occurrence along the Mesoamerican Subduction Zone,” the USGS said.

“Both the 8.0 event of 1985 as well as the 7.1 earthquake near Matzaco (Puebla), in 2017, occurred on the date of September 19. Despite the coincidence, there is no specific date or time of year in which Mexico is statistically more prone to seismic activity.”

In its preliminary analysis, the USGS stressed that the area of ​​the Mexican Pacific where the epicenter of Monday’s earthquake is located is prone to earthquakes and recalled that since 1972 another 13 large earthquakes had had their epicenter within a radius of 250 kilometers around of said area.

“In the previous 50 years, 13 other earthquakes of magnitude 6.5 or greater have occurred within 250 kilometers of (today’s) event. This includes the 1995 magnitude 8 event approximately 125 kilometers to the northwest, as well as the 8 degrees 1985 approximately 80 kilometers to the southeast”

Although its final analysis has yet to be published, the USGS said it could say that Monday’s event was triggered by the sliding of the boundary zone of the Cocos tectonic plate under the North American tectonic plate after the two collided in the Mesoamerican subduction zone.

“The 7.6-magnitude earthquake of September 19, 2022 near the Pacific Coast of Mexico occurred as a result of surface thrust between faults. The location, depth, and mechanism of the event are broadly consistent with slippage at or near the boundary interface between the sinking oceanic Cocos plate and the North American plate,” he said.

“The tectonic movements of the Pacific coast of Mexico are largely controlled by the northeastward sinking of the Cocos plate under the North American plate at a rate of about 70 millimeters per year.”

Dependent on the US Department of the Interior, the USGS is in charge of the National Earthquake Information Center (NEIC) whose headquarters are located in the State of Colorado and from where it monitors earthquakes that they consider to be of a notable nature. 24 hours a day.

According to the USGS itself, the NEIC produces around 20,000 reports of notable earthquakes in US territory that have a minimum intensity of 3 degrees on the Richter scale; the NEIC also monitors earthquakes of at least magnitude 5 in other parts of the world or that have caused significant damage.

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