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This screenshot of a night eruption in bright moonlight is from one of the webcams that are part of round-the-clock monitoring at Mexico’s iconic Popocatépetl — pronounced “popo-ka-TEH-petal” rather than “po-po-CAT-eh-petal” — the second tallest active volcano in North America, after dormant Pico de Orizaba, a/k/a Citlaltépetl.
Both fire mountains, along with the country’s most populous states, its national capital, major industrial centers, and some gorgeous scenery, are part of the Trans-Mexican Volcanic Belt.
This is in a tectonic collision zone where, many miles underground, an oceanic plate or plates are moving down into the mantle under the leading edge of North America’s continental plate — and melting a lot of rock in the process.
Surrounded by more than 20 million people, Popocatépetl woke up in December 1994 after a seven-decade nap and still rumbles on today, mostly with low-level lava dome building and relatively mild but spectacular explosive dome destruction.
What is Popocatépetl?
In order to really see this volcano, we need to keep both eyes open.
Intuition
The intuitive eye has a direct line to our hearts. It’s how local small-town folks see Popocatépetl in this 2002 ClioTV documentary, El volcán que escucha, “The volcano that listens.”
In it, according to the YouTube autotranslation, anthropologist Julio Glockner says:
City people have an exclusively visual relationship with volcanoes, unlike country people, who have a physical relationship, no, a tactile relationship, no, the volcano, they breathe it, they work on its slopes; from it they get water, firewood, stone for construction; in short, there is a body-to-body relationship, let’s say, with the mountain.
Some of these people live in Santiago Xalitzintla, less than eight miles from Popocatépetl’s summit, and they go willingly into harm’s way on certain occasions, a few of which are explored in a companion video to “The volcano that listens.”
According to more recent English-language media, the faithful in Xalitzintla reportedly said in 2023 that the volcano became more troublesome (which it did, temporarily, with increased exposiveness) because they had not been allowed to go up onto the summit to perform ritual observances on March 12th, the volcano’s birthday.
These rituals probably have their basis in both longstanding pre-Hispanic practices and centuries of local Catholic tradition (a UNESCO World Heritage site of sixteen monasteries from the early 1500s is located on Popocatépetl’s periphery).
The volcano is Don Gregorio Chino Popocatépetl, or Don Goyo, and, according to the faithful, it occasionally takes the form of an old man who appears to individuals — particularly those who have been struck by lightning — and tells them that, from now on, they are specially chosen to lead religious rites and to control the weather in various ways.
March 12th is the traditional feast day for the Catholic saint Gregory the Great (although this has been moved to September 3 in some denominations).
In 2024, the faithful from Xalitzintla went up into the 12-km exclusion zone of this active volcano, accompanied by media.
This year, things are a little different.
The town of San Nicolas de los Ranchos, which is also quite close to the fire-filled summit, is holding the first “Don Goyo Fest” on March 11 and March 12, 2025. It is in a safe place, outside the exclusion zone and near a shelter, just in case. Outsiders and foreigners, as well as locals, are welcome
There are no shelters up in the high places, inside the exclusion zone, where the traditional ritual celebration will be held (at last report, without word on whether that would be open to the public).
Science
We also need to use our objective eye on Popocatépetl, which is how official decision-makers, volcanologists, and the millions of residents in Mexico City, Puebla, and other urban centers just tens of miles from the volcano see it.
Popocatépetl erupts frequently but has been this mellow (mostly VEI 1 and 2 eruptions, per the Smithsonian’s Global Volcanism Program) throughout most of recorded history, which goes back to the 1300s AD in these parts, with a European perspective since the 1500s.
That doesn’t fool the scientists.
They take the long view of this ~23,000-year-old volcano and have found plenty of evidence, recent, as well as in the distant past — of Popocatépetl’s:
- Enormous mudflows (or lahars, an Indonesian word that volcanologists worldwide have adopted for slurries of volcanic ash and water)
- Multiple Plinian eruptions (VEI 4+) that have buried whole Mesoamerican towns under ash and also, as the last ice age was winding down, tossed “Tutti Frutti” rocks — orange pumice containing gray, pale green, and bright green minerals and other bedrock fragments — into what’s now downtown Mexico City.
That is not mellow at all!
- There is also evidence of a few extensive lava flows from flank vents, the largest of which is the Pedregal de Nealtican, an 11-mile-long silicic flow that oozed down the ravines and out over flat land a few months to years after the Tutti Frutti Eruption’s explosive phase had ended (Ramirez-Uribe et al.).
- Finally, geoscientists have identified at least three sector collapses — Mount St. Helens type landslides where both summit and flank gave way.
Yes, there were lateral blasts, too, according to Siebe and Macias, as the hydrothermal system exploded. Then the volcano went plinian, just as Mount St. Helens did in May 1980.
Apart from ritual, some folk memory of this bad boy’s past tantrums still exists in town and place names.
Siebe and Macias note that “Cholula,” the name of a very old city in Puebla State east of Popocatépetl, can be translated as “place of those who fled” or “water that falls on place of those who fled.”
They say that Cholula was temporarily abandoned in the 800s AD and that Popocatépetl’s last Plinian eruption also was in the 800s.
Although a definite link between those two events had yet to be established at the time of that study, massive lahar deposits running all the way to the first steps of Cholula’s famous pyramid do suggest that it was cause and effect.
Today the area is so densely populated that a repeat event would be catastrophic.
Here’s another example.
“Xalitzintla” means “ash-stream,” in Nahuatl (Siebe and Macias), the same native language that named this volcano popocatépetl: “smoking mountain.”
As mentioned, the town of Santiago Xalitzintla is less than eight miles from Popocatépetl’s summit (which rises almost 18,000 feet above sea level). Xalitzintla also is located near one of the deep ravines that lead off the volcano’s steep, ash-strewn slopes.
A haze of ash did fall on the hill towns in 2023, when the volcano became more explosive than usual, but another kind of “ash-stream” has brought down the rocks and boulders of dark gray andesite that now litter Xalitzintla and are used as building material: a lahar or lahars caused by rain or, back when Popo had a glacier, glacial meltwater.
Since 1994, that ice has almost disappeared. Pyroclastic flows probably melted it, causing small lahars that reached the edges of Santiago Xalitzintla in 1997 and 2001. (Siebe and Macias)
The much larger mudflow that left boulders in town was prehistoric, but it is not ancient.
Ash is still accumulating on this erupting volcano, rains can be heavy, and another lahar like it will happen again some day.
Popocatépetl and people
Faithful tiemperos and their followers aren’t the only ones who ignore the 12-km exclusion zone around Popocatépetl’s summit.
With much less reason, mountaineers have gone up there, and some have been killed up there in explosions. Adolescents visit the summit crater on quiet days. Tourists have been there, too, and some have been killed or injured by dome blasts.
The volcano is easily accessible, close to the well-traveled Paso de Cortes, between Mexico City, on the western side of the Sierra Nevada volcanic range, and the city/state that is Puebla to the east.
How would you protect tens of millions of human beings from Popocatépetl?
Next, in this two-part series, we’ll look at the initial years of this eruption, from December 21, 1994, to the first decade of the twenty-first century, and see how the present monitoring network and civil protection agencies have grown to meet this challenging task.
Sources:
- De la Cruz-Reyna, S., and Carrasco-Núñez, G. 2002. Probabilistic hazard analysis of Citlaltepetl (Pico de Orizaba) volcano, eastern Mexican volcanic belt. Journal of Volcanology and Geothermal Research, 113(1-2), 307-318.
- De la Cruz-Reyna, S.; Tilling, R. I.; and Valdés-González, C. 2018. Challenges in responding to a sustained, continuing volcanic crisis: the case of Popocatepétl volcano, Mexico, 1994-present. Observing the Volcano World: Volcano Crisis Communication, 235-252. https://link.springer.com/chapter/10.1007/11157_2016_37
- El Sol de Puebla. 2025. Llega “Don Goyo Fest” para festejar el cumple del Popocatépetl. Last accessed March 10, 2025. https://oem.com.mx/elsoldepuebla/local/llega-don-goyo-fest-para-festejar-el-cumple-del-popocatepetl-22079028
- Fitzgerald, R. H.; Kennedy, B. M.; Wilson, T. M.; Leonard, G. S.; and others. 2018. The communication and risk management of volcanic ballistic hazards. Observing the volcano world: Volcano crisis communication, 121-147. https://link.springer.com/chapter/10.1007/11157_2016_35
- Global Volcanism Program. 2025. Popocatepetl. https://volcano.si.edu/volcano.cfm?vn=341090
- Moriano Tello, D. E.; Paredes Ruiz, P. A.; Córdoba Guerrero, G.; and Delgado Granados, H. 2017. Evaluación de la vulnerabilidad de edificaciones ante la génesis de lahares: Caso de estudio en la población de Santiago Xalitzintla, en el flanco NE del volcán Popocatépetl (México). Boletín de la Sociedad Geológica Mexicana, 69(1), 223-241.
- Plunket, P., and Uruñuela, G. 1998. Preclassic household patterns preserved under volcanic ash at Tetimpa, Puebla, Mexico. Latin American Antiquity, 9(4), 287-309.
- Ramírez-Uribe, I.; Siebe, C.; Chevrel, M. O.; Ferres, D.; and Salinas, S. 2022. The late Holocene Nealtican lava-flow field, Popocatépetl volcano, central Mexico: Emplacement dynamics and future hazards. GSA Bulletin, 134(11-12), 2745-2766.
- Siebe, C.; Abrams, M.; Luis Macías, J.; and Obenholzner, J. 1996. Repeated volcanic disasters in Prehispanic time at Popocatépetl, central Mexico: Past key to the future?. Geology, 24(5), 399-402. (Abstract only)
- Siebe, C., and Macías, J. L. 2004. Volcanic hazards in the Mexico City metropolitan area from eruptions at Popocatépetl, Nevado de Toluca, and Jocotitlán stratovolcanoes and monogenetic scoria cones in the Sierra Chichinautzin Volcanic Field.
- Sosa-Ceballos, G.; Gardner, J. E.; Siebe, C.; and Macías, J. L. 2012. A caldera-forming eruption~ 14,100 14C yr BP at Popocatépetl volcano, México: Insights from eruption dynamics and magma mixing. Journal of Volcanology and Geothermal Research, 213, 27-40.
- Tribune Noticias. 2025. Popocatépetl: ¿Quienes eran Don Goyo y los tiemperos que controlan el clima? https://tribunanoticias.mx/popocatepetl-quienes-eran-don-goyo-y-los-tiemperos-que-controlan-el-clima/ Last accessed March 10, 2025.
- Wikipedia. 2025. Demographics of Mexico. Last accessed March 2, 2025. https://en.m.wikipedia.org/wiki/Demographics_of_Mexico
- ___. 2025. Monasteries on the slopes of Popocatépetl. Last accessed March 2, 2025. https://en.m.wikipedia.org/wiki/Monasteries_on_the_slopes_of_Popocat%C3%A9petl
- Verza, M. 2023. Threatening 22 million people, Mexico’s Popocatepetl is a very closely watched volcano. https://apnews.com/article/mexico-volcano-popocatepetl-scientists-baad6e912809ffa4d9586015209e0d2d
Flight To Wonder 