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A Volcanic Eruption In The Southwest US Could Surprise Us Soon

Lava-driven eruptions have made headlines in recent months in Iceland, Italy and Guatemala. The US Geological Survey (USGS) says that while the southwestern United States isn’t commonly thought of as a hotbed of volcanic activity, it’s arguably the next place in the nation to blow its top.

A few hours west of Albuquerque, New Mexico tourists can drive through a relatively young lava flow in El Malpais National Monument; the Sunset Crater Volcano National Monument lies within an active volcanic field near Flagstaff, Arizona and even looking out my window near the Colorado-New Mexico border I see a landscape dotted by old volcanic mounds and mountains.

“There are thousands of volcanic features distributed throughout the southwest United States, which are grouped together in volcanic fields,” explains USGS volcanologist Wendy Stovall in a recent blog post.

And yet, in the United States, when we think about volcanoes we turn our attention – and dedicate our research resources – first to the Yellowstone region and the volcanoes of the Cascade Range in the northwest.

It’s easy to understand why: one of those volcanoes has had a major eruption within living memory (Mount St. Helens in 1980) and the Cascades loom over some major population centers along the Pacific coast.

“This means we know relatively little about eruption timing for the majority of U.S. volcanic fields,” Stovall adds. “Even so, the sparse geologic evidence we do know suggests one cinder-cone and lava-flow type eruption every 700 years in a typical volcanic field, meaning that it is more likely there will be an eruption from one of these fields (in the southwest) during the next decades than an eruption from most Cascade volcanoes (with the exception of Mount St. Helens—the most active volcano in the Cascade Range by far).”

And if there were to be an eruption in the southwest this century, it might look like the high-profile volcanic activity we’ve seen so far in 2021 from Mt. Etna in Italy, Geldingadalur volcano in Iceland or Pacaya in Guatemala. The types of erupting magma seen at these sites are similar to what we would expect from volcanoes in the southwest US.

“Eruptions in volcanic fields, like those of the southwest, can last for days to years,” Stovall writes. “The 1943 eruption of Paricutin, in Mexico, which lasted for 9 years, is a good example of what could occur in the U.S.”

Impacts to life in adjacent communities and broader effects on air travel, water storage, transportation and communications could be expected in the case of such an eruption. Residents living near Hawaii’s Kilauea volcano during its eruption in 2018 can attest to the experience. It could also be something like living near a burning wildfire, but one that lasts for months or years.

“Ashfall can be cleaned up, but even small amounts can damage wastewater systems, air conditioning and heating systems, and agriculture and livestock. These eruptions emit tonnes of sulfur dioxide and would degrade downwind air quality,” Stovall says.

Many dire predictions for the southwestern US call for dry landscapes under the grip of droughts fueled by climate change. But that apocalyptic scenario could also play out with a few lava fountains in the background as well.