CHICHONAL: GEOLOGY, CHARACTERISTICS AND 1982 ERUPTION - GEOGRAPHY - 2025

El Chichonal , also called Chichón, is a volcano located in the state of Chiapas, in southern Mexico. According to experts, it is one of the most active in the country, dating back to its last eruption in 1982. It was one of the most destructive events of this type in the entire 20th century.

The volcano is of a stratified type, with a typical cone shape and of great height. Specifically, the Chichonal reached 1,260 meters before the great eruption of the early 1980s. Stratovolcanoes consist of several layers, formed by hardened lava and pyroclasts.

The 1982 eruption caused around 2,000 victims, in addition to completely destroying several nearby towns. Data collected by scientific stations in the United States indicate that the ash cloud formed was more than 3 kilometers thick.

This cloud settled at about 20,000 meters high and practically surrounded the entire planet. Studies have been underway for a few years to try to take advantage of its potential to generate geothermal energy.

Geological history

The Chichonal or Chichón volcano is located in the municipality of Chapultenango, in the Mexican state of Chiapas. It is one of the most active volcanoes in the entire country and even in the entire continent.

Its diameter reaches one kilometer, while the depth is 160 meters. Like most stratovolcanoes, its height is considerable, although it has undergone changes in recent years. Until the great explosion of 1982 it was 1,260 meters above sea level. After the eruption, its altitude dropped to 1060 meters.

The geologists in charge of their study calculate that the Chichonal was formed about 220,000 years ago, being the one that is less old than those that are located in its Arc.

characteristics

As previously mentioned, it is a stratovolcano, which is made up of different layers of lava, ash and other materials released by the eruptions that occur.

The geological zone in which it is found is called the Chiapanecan Volcanic Arc. This is located between the Trans-Mexican Volcanic Belt and the Central American Volcanic Arc.

Stratified volcanoes are considered the most dangerous when active. The reason is that they do not normally spew lava, but ash and potentially poisonous gases.

On the other hand, there is currently a lake inside the crater. The water accumulated during the second half of 1982, after the eruption. It stands out for its shallow depth, for the hot steam and for the acidity of the liquid.

Crater structure

The Chichonal crater measures about 2 kilometers in diameter and is known as Somma. The inner part has vertical walls, while the outer ones have a softer slope.

Exercise

By studying the different layers and the geological composition of the surroundings, a rough estimate of the eruptions that have taken place can be obtained.

It is noted that these have been at least 12, spread over the last 8000 years. This indicates that approximately every 300 years the volcano erupts.

Possible eruption in 1850

There is disparity about the possibility that the volcano erupted in 1850. The oral tradition of the inhabitants of the area affirms that it did happen on that date, but geologists do not find any evidence.

Scientific data indicate that the one before the one known in 1982 must have occurred about 1000 years ago

1982 eruption

The most recent eruption of the Chichonal took place on March 28, 1982. In reality, there were three different ones within the same event. The last explosion occurred on April 4.

The effects on nearby towns were devastating, with between 1,700 and 2,300 people killed and more than 20,000 locals losing everything. It also caused large economic losses, especially due to the death of livestock and the destruction of large agricultural areas.

This eruption was preceded by several weeks in which an increase in seismic activity was detected in the area. In the end, the violent outbreak of the volcano opened a crater 1 kilometer wide, in which today is a lake.

First eruption

Framed within the so-called Plinian events (in memory of Pliny the Elder, witness to the explosion of Mount Vesuvius in Italy), the first great explosion took place on March 28, 1982 at 9 pm.

The column produced by the eruption reached 20 kilometers high. For 6 hours, the volcano was throwing its destructive material.

Second eruption

With no time to recover, the volcano erupted again on April 3. It was accompanied by almost 30 earthquakes per hour during the morning of that day and one per minute during the afternoon.

At 7:35 p.m. the mountain erupted, causing large pyroclastic waves that reached up to 8 kilometers beyond the crater. Pyroclastic flow is a mixture of different very hot elements, such as gases, solid materials, and trapped air. It is always at ground level, destroying everything it encounters.

This second outbreak was three times greater than the one that occurred in Santa Helena 4 years earlier and affected the entire territory located within a 100 km radius. Chiapas, Tabasco, Campeche and part of Oaxaca and Veracruz were affected by the expelled ash.

The worst effects were suffered by the nearest towns, small municipalities that completely disappeared.

Third eruption

There would still be a third explosion, which took place on April 4. It was so powerful that the ash cloud came to surround the entire planet. The pyroclastic material reached 750º in temperature, with currents 8 kilometers long and 150 meters wide.

Other notes on the Chichonal

The legend of the burning woman

There was a curious legend related to the volcano in the area, a reflection of the fact that in the cultural memory of the settlers there was concern for inhabiting its surroundings.

It is said that a beautiful white woman with blond hair appeared one day in the neighboring towns, belonging to the Zoque tribe. The woman fell in love with the men, but a certain fear made no one agree to live with her.

Rejected and furious, she showed her true face and ran for the mountains. As he did so, he vowed revenge. It is she, known as Pyogba Chu'we, "the fiery woman", who the indigenous people blame for the eruptions.

Studies to obtain geothermal energy

The Chichonal volcano is currently being studied by the Federal Electricity Commission of Mexico. The objective is to try to take advantage of its qualities to produce geothermal energy.

The result of the first studies has been positive, so perhaps one day the volcano will become an energy source from which to extract electricity.

References

1. Volcano Discovery. El Chichón volcano. Retrieved from volcanodiscovery.com
2. Gutierrez, Oscar. They commemorate 35 years of the eruptions of the Chichonal volcano in Chiapas. Obtained from eluniversal.com.mx
3. Uriel Arellano Contreras and Esteban Jiménez Salgado. Geological-structural evaluation of the Chichonal volcanic complex, Chiapas, as an alternative source of energy. Recovered from 132.248.9.34
4. S. De la Cruz-Reyna, AL Martin Del Pozzo. The 1982 eruption of El Chichón volcano,

   Mexico: Eyewitness of the disaster. Recovered from researchgate.net

5. Klemetti, Eric. Looking back at the 1982 eruption of El Chichon in México. Retrieved from wired.com
6. Milesbeyond. Chichonal Volcano. Retrieved from milesbeyond.it
7. Backyardnature. Chichonal Erupts. Retrieved from backyardnature.net
8. Wendell A. Duffield, Robert I. Tilling, Rene, Canul. Geology of El Chichon volcano, Chiapas, Mexico. Retrieved from sciencedirect.com