Recent Earthquakes in Mexico

By Bailey Andress

A collapsed building in Mexico City following the 1985 earthquake. Photo credit: Roberto Esquivel Sánchez. Courtesy of Wikimedia Commons.

On September 19, 1985, Mexico City was rocked by the deadliest recorded earthquake in the country’s history. Numerous residents awoke at 7:18 a.m. to a rumbling 8.1-magnitude earthquake that lasted three minutes. Several of Mexico City’s hotels, factories, and residences crumbled, and a handful of gas mains ruptured, igniting fires throughout the city. The disaster resulted in an estimated death toll of 10,000 citizens, as well as 30,000 injured and even more left without homes. Thirty-two years to the day after the infamous 1985 earthquake, the city trembled again as a result of another powerful quake, one of a series of three major seismic episodes which impacted Mexico last month.

Enrique Rebasen school collapse. Photo credit: Miguel Tovar/AP. Courtesy of ABC News.

This particular quake had a magnitude of  7.1 on the Richter Scale and sent seismic waves from its epicenter, located 31 miles below the ground’s surface in Ayutla, a town southeast of Mexico City. The earthquake was especially impactful due to its proximity to the ground’s surface and resulted in damage to the power grid, along with dozens of collapsed buildings. In the capital, part of an elementary school building shifted briefly before crumbling and trapping schoolchildren beneath rubble. Rescue groups have declared that at least six adults and 19 enrolled children perished in the earthquake, and a significant portion of the students are still missing. The United States Geological Survey confirmed that at least 340 people lost their lives in the earthquake, with 198 of the fatalities in Mexico City. Mexican president Enrique Peña Nieto addressed the natural disaster with a three-day period of national mourning, along with a Twitter announcement that emphasized the importance of searching for and rescuing trapped citizens. The Mexican military contributed to recovery efforts by dispatching 4,000 military members to Mexico City and affected areas nearby. Mexican authorities were already focused on relief, as a previous earthquake had occurred only 11 days earlier.

USGS Shakemap. Image credit: United States Geological Survey.

The earthquake on September 8 was even more powerful. Centered off the southern coast of Mexico, the whopping 8.1 magnitude quake could be felt as far away as Mexico City and Guatemala City. Of the 61 fatalities resulting from the earthquake, the majority of deaths and injuries occurred in the Chiapas and Oaxaca states of Southern Mexico. In Chiapas, officials reported that 400 houses had been completely destroyed and 1,700 others were damaged. The estimated economic losses were less than one percent of the Mexico’s GDP, but the afflicted regions already contained the country’s highest percentage of citizens living in poverty, making recovery efforts even more challenging.

Ixtaltepec bridge damage. Photo credit: Mexico News Daily.

The most recent major earthquake to strike Mexico occurred on September 23. The earthquake’s epicenter was located 9.1 km below the surface of Earth’s crust near Matias Romero in the state of Oaxaca . Unlike the two prior quakes, the magnitude was 6.1, which resulted in far less damage. The majority of structures that fell had been weakened by previous earthquakes, and the consequences were less severe. In a tweet, President Peña Nieto expressed that repairing these structures, along with a collapsed bridge in Ixtaltepec, was the primary focus of recovery efforts.

Tectonic plates below Mexico. Image credit: Mike Norton, courtesy of Wikimedia Commons.

Although the recent earthquakes in Mexico seemed sudden to both Mexican and global citizens, the major seismic activity comes as no surprise to experts in the field. In an interview with The New York Times, geophysicist Dr. Gavin Hayes of the U.S. Geological Survey stated that Mexico is prone to earthquakes due to its position above a “subduction zone,” or an area where building friction between tectonic plates results in an oceanic plate sliding beneath a neighboring continental plate. In Mexico’s case, powerful tremors are caused by the subduction of the Cocos oceanic plate below the North American continental plate. Citizens of Mexico City are at a certain disadvantage as they are more likely to experience particularly severe earthquakes. The dried lakebed below Mexico City intensifies ground shaking due to tremors. When seismic waves move below the city, the soft ground below shifts easily, in a manner that seismologist John Vidale compares to “Jell-O on a plate.”

Colegio Carol Baur. Photo credit: Collegiate School.

With news of the destruction in Mexico due to September’s earthquakes, many members of the Collegiate community sought updates on Colegio Carol Baur, Collegiate’s partner school in Mexico City. Director of Global Engagement and Inclusion Erica Coffey stated, “Carol Baur is like family to Collegiate, [so] many of our faculty and students were concerned when they heard about the earthquake.” Fortunately, Carol Baur’s students, facilities, and faculty all emerged from the earthquakes unscathed. Although classes were briefly cancelled after the 7.1 magnitude quake that severely impacted Mexico City, the Carol Baur community quickly resumed classes as normal and focused on recovery efforts, particularly distributing safe water to afflicted citizens. Thankfully, Carol Baur delegates participated as scheduled in the International Emerging Leaders Conference at Collegiate this week.

Featured image credit: United States Geological Survey.

About the author

Bailey Andress is a junior at Collegiate.