Decade Volcano: Santa Maria

Watch out for the quiet ones.

They always get overlooked until internal pressures reach the breaking point and there is an explosion.

Santa Maria

For instance, everyone in 1902 Guatemala knew that Santa Maria, seventy miles west of the nation’s capital, was a volcano. Its tall, pointy shape showed that.

But Santa Maria slept through the conquistador era and probably had been dormant for many centuries before that.

Eric Menjivar, CC BY 2.0

Life around it was pretty good as the 20th century dawned.

  • Local natives climbed more than 12,000 feet to conduct Mayan ceremonies at the summit.
  • Small farms and plantations of coffee, cardamom, and other specialty crops thrived on Santa Maria’s fertile, undisturbed slopes.
  • Sleepy little villages were scattered around the volcano’s feet, while beautiful colonial-era architecture lined the streets of Quetzaltenango — the departmental capital — just seven miles north of the volcano.

Guatemalans have always lived with more active volcanoes than most people do. (Johrendt) They had other fire mountains to worry about.

And earthquakes were a big concern, too, that year. A series of major sismos, affecting all of western Guatemala, had started in January, 1902.

A street in Quetzaltenango. (Image: Tomas Zanotti via Wikimedia, public domain)

The worst one, on April 19th, was centered underneath Santa Maria. (Williams and Self)

Hundreds of people died when this M7.5 shock hit at around 8:30 that evening, collapsing many buildings and causing other structural damage in Quetzaltenango and other departments.

By autumn, more than forty quakes were happening each month. (Photovolcanica)

But nobody connected these troubles with the volcano.

Then, at around 5 p.m. on Friday, October 24th, while misty weather shrouded Santa Maria, villagers in San Felipe heard what sounded to them like a huge waterfall or an exploding industrial boiler. Farther north, residents of Quetzaltenango saw dark clouds and thought a storm was upon them until sandy pumice and ash began to fall from the sky.

By 8 p.m., the mist was gone, and Santa Maria’s lightning-studded eruption column was visible, rising above its southern flank.

This was bad enough, but the eruption then intensified overnight. Williams and Self report that the volcano was in plinian mode for 18 to 20 hours.

A ship captain off the nearby Pacific coast measured Santa Maria’s column at some point during this phase and found it to be over 17 miles high!

White steam clouds mixed with ash as the eruption slowed down. (Image: Wikimedia)

The worst was over by Sunday evening, October 26, though Santa Maria continued to rumble and sputter until mid-November.

It turned out to be the 20th century’s second largest eruption, a VEI 6 blast surpassed only by Novarupta/Katmai in 1912.

But Novarupta and Katmai rampaged over the Alaskan wilderness, inconveniencing modern society only with heavy ashfall on Kodiak Island.

Santa Maria erupted in a densely populated region.

It’s impossible to get consistent death toll figures. Thousands perished, certainly. The only documentation I can find lists either 2,455 direct deaths/2,000 from disease (Brown et al.) or 2,000-3,000 directly/5,000 to 10,000 from disease (Oppenheimer).

If correct, Oppenheimer’s totals make this the tenth most deadly eruption on record.

But this 1902 eruption isn’t the only reason why Santa Maria is on the Decade Volcano list.

The volcano had another surprise in store.

Spoiler: Santa Maria started filling in the gigantic scar left by the 1902 eruption. (Image: Fernando Reyes Palencia, CC BY-SA 2.0)


While the devastated region slowly recovered, Santa Maria had low-level eruptions between 1903 and 1913.

These occurred on the east end of the half-mile-wide, thousand-foot-deep hole that the 1902 eruption had blasted out of the southwest flank.

Then, on June 22, 1922, the southwest flank opened up again and a lava dome started piling up, then another, yet another, and finally the most recent one: Caliente, which is about 700 feet wide today and topped with a slow-moving lava flow. Its summit is about 8,200 feet above sea level.

Be very sure of your footing up here and move carefully. I think that’s Caliente on the left.
(Image: worldroadtrip/Shutterstock)

The whole complex is called Santiaguito or the Santiaguito Volcano, though it is still a part of Santa Maria. Indeed, petrology shows that this lava is almost identical to what Santa Maria erupted with great force in 1902.

Each dome can have more than one vent, and the youngest older domes are to the east. From 1972 to 1986, there was also activity at the dome just west east of Caliente, but now Caliente is on its own, without any sign of slowing down.

In two years, this ongoing eruption will be a century old!

Volcanologists as well as tourists love the fact that you can look down on Caliente’s vent from the summit of Santa Maria, about 4,000 feet higher.

This change in activity and extended period of activity also makes Santa Maria a Decade Volcano, as do the variety of hazards here and need for close monitoring.

And Santiaguito, like its parent, is a threat to many people.

The sort of lava that can build domes is also the type to suddenly break off in chunks that quickly turn into a pyroclastic flow.

As the video up above shows, these happen at Santiaguito. So do lava flows, lahars (volcanic mud flows), explosions with their accompanying hazards, and toxic gas emissions.

The most deadly pyroclastic flow here happened in 1929, when the dome partially collapsed while thousands of people were on the mountain, attending a religious festival. Again the toll is uncertain, but it appears that at least 3,000 people died that day. (Ball, 2010)

Volcan Santa Maria does not mess around.

Mariano Valverde, from Quetzaltenango, was Guatemala’s “waltz king” and had a successful US recording career during the early 20th century. This waltz — “Moon Night Among Ruins” — has special meaning for Guatemalans. Valverde’s mom died in the April 19, 1902, earthquake; some say he wrote this waltz for that, while others point to another quake in 1917. It’s included here because I hear in it the capacity for great sorrow, hope, and courage that is required of those who live near Santa Maria.


14.757° N, 91.552° W, in Quetzaltenango Department, southwest Guatemala. The GVP Volcano Number is 342030.

Nearby Population:

Per the Global Volcanism Program:

  • Within 5 km (3 miles): 8,675
  • Within 10 km (6 miles): 119,462
  • Within 30 km (19 miles): 1,259,600
  • Within 100 km (62 miles): 6,197,420

Current Status:

I could not find an alert level or aviation code. Here is the July 9th bulletin.


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