Things That Matter

Following Massive Earthquake Swarm, Scientists Fear A New Volcano Could Be Forming In Mexico

Mexico is no stranger to major earthquakes – or massive volcanoes. In fact, it was just in 2017 that a major quake devastated cities across the country (including the capital, Mexico City) on what was the 32nd anniversary of an even more devastating quake.

But scientists are paying special attention to a recent swarm of earthquakes taking place in the Mexican state of Michoacán, as there are fears that it could be the result of a new and rapidly forming volcano.

Scientists are watching as earthquakes swarm central Mexico.

Scientists in Mexico are considering – for the second time in less than two years – the possibility that there is potentially a new volcano forming in Michoacán in the wake of increased seismic activity. Just between May 1 and June 8 there were 236 low-magnitude earthquakes and six temblors with a magnitude above 4.0 in the area surrounding the city of Uruapan. There were also more than 300 micro-quakes in the same area in the first four months of the year.

Carlos Valdés González, a researcher at the Institute of Geophysics at the National Autonomous University (UNAM) and a former National Disaster Prevention Center chief, said it’s essential to monitor such earthquake swarms — the name for sequences of similar magnitude seismic events occurring in a local area in a relatively short period of time — because they could indeed foretell the creation of a new volcano.

He told the newspaper Milenio that for a volcanic eruption to occur and for a new volcano to form, there must be seismic activity.

“… Mexico is a volcanically active country, especially in that region [near Uruapan], where there are more than 1,200 small volcanoes in the so-called Michoacán-Guanajuato volcanic field,” Valdés said.

It wouldn’t be the first time that a volcano rapidly emerged in the area.

In 1943, the Paricutín volcano – which is located about 30 miles from Uruapan – suddenly emerged in a corn field following a series of minor earthquakes. Over the course of its nine year eruption, the volcano had grown to nearly 1,400 feet tall and had significantly damaged an area of more than 90 sq. miles with the ejection of stone, volcanic ash and lava. Three people were killed, two towns were completely evacuated and buried by lava, and three others were heavily affected. Hundreds of people had to permanently relocate, and two new towns were created to accommodate their migration. 

It’s with that devastating eruption in mind that scientists are keeping a watchful eye on potential development. Last year, a team of experts carried out similar studies after more than 3,000 low magnitude earthquakes were recorded in January and February, but it was ultimately determined that the increased seismic activity would not lead to the birth of a new volcano. Scientists concluded that most of the magma movements detected were horizontal rather than vertical and for that reason, the molten material would not ascend to the surface.

Denis Xavier Francois Legrand, another UNAM researcher, confirmed that while an earthquake swarm is an important marker of the development of a new volcano, it is not the only one. Experts are also looking for potential deformation in the Earth’s crust that allows a volcano to pierce through from below and the upward, rather than sideways, movement of magma.

“We assume that these [earthquake] swarms are associated with the movement of magma, but it doesn’t always reach the surface. These swarms [also] occurred in 1997, 1999 and 2006, but magma didn’t reach the surface [of the Earth]. Perhaps the same thing is happening now, but it’s very important to keep monitoring [the magma movements],” Francois told a virtual press conference Tuesday.

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