A major eruption of Mexico volcano would impact U.S.
Other volcanoes in Hawaii, Alaskan islands currently erupting
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For weeks, the 17,802-foot Popocatepetl volcano 50 miles southeast of Mexico City has shaken nearby homes and buildings, and deposited a thin layer of ash upon fields and towns.
On May 21, officials in Puebla, a city of 1.7 million people 30 miles east of the volcano, announced that school classes and state parks would close in areas closest to Popocatepetl. Some airports have briefly shut down due to ash on runways. Troops have been called in to prepare for the worst.
The activity at Popocatépetl intensified recently. On May 17, tremors lasted more than ten hours, and there were some 168 steam, gas, and ash emissions and minor-to-moderate explosions. By May 23, tremors lasted more than 20 hours with “ongoing” steam, gas, and ash emissions, according to a report by the Global Volcanism Program run by the Smithsonian Institution and U.S. Geological Survey. Ash plumes rose as high as 2.3 miles above the summit.
While officials aren’t yet recommending evacuations, they advised residents near Mexico’s second-highest mountain to “familiarize yourself with evacuation routes and provisional lists of temporary shelters.” In June 2022, a climber was killed there after being hit by hot volcanic rocks.
It’s a scene reminiscent of developments in the weeks before the worst volcanic eruption in U.S. history occurred in southwestern Washington state 43 years ago. The Mount St. Helens disaster resulted in the deaths of 57 people, mostly due to asphyxiation by inhaling the fiery ash. Lava, mud slides, ash, and other effects caused an estimated $1 billion in damage, including to 187 miles of roadways.
The eruption reached an estimated height of 80,000 feet and deposited tons of ash and other debris across 11 states and several Canadian provinces. Light ash fell as far as Oklahoma City some 1,900 miles away. Heavier ash fell closer to the blast.
Other volcanoes erupting in Hawaii, Alaska, elsewhere
Popocatepetl is one of several active volcanoes in North America. The 4,091-foot Kilauea in Hawaii has erupted this year and is on a heightened watch. In 1790, that volcano blasted the island well before it became a U.S. territory and state, killing more than 400 people. The roughly 4,000-square-mile island of Hawaii now has about 200,000 residents.
The 5,710-foot Great Sitkin and 4,006-foot Semisopochnoi Island volcano in Alaska’s Aleutian Islands, as well as the submerged Ahyi Seamount in the Northern Mariana Islands, are among others seeing current eruptions. The 69 Aleutian Islands have a combined population of about 8,000, while the 14 Northern Mariana Islands have some 56,000 residents.
Indonesia has more volcanoes currently erupting than any other country with nine, according to the Global Volcanism Program. The U.S. and its territories have four, while Japan, Russia, Ecuador, and Papau New Guinea are seeing activity in three apiece. Other North American countries with activity are El Salvador, Costa Rica, Guatemala, and Nicaragua.
Mexico volcano much taller than St. Helens
Popocatepetl is almost twice as high as St. Helens and more threatening. San Antonio is about 870 miles north of the volcano. A major eruption there would impact Texas and other states, as well as potentially destabilizing the country bordering those states.
One advantage these days is scientists have better technology and instruments to predict major eruptions and thus warn people to evacuate. In 1980, volcanologists like USGS scientist David A. Johnston had to rely on fairly primitive equipment to warn people. Johnston’s research focused on developing better warning processes, such as through sampling gases that emitted. He and other USGS scientists successfully convinced officials to evacuate people weeks before the major eruption, as smaller eruptions intensified. They also resisted pressure to reopen the region, thus saving many lives, officials said.
“The volcano-monitoring effort of which [Johnston] was part helped persuade the authorities first to limit access to the area around the volcano, and then to resist heavy pressure to reopen it, thereby holding the May 18 death toll to a few tens instead of hundreds or thousands,” USGS scientists Peter W. Lipman and Donal Ray Mullineaux wrote in a 1981 report, The 1980 eruptions of Mount St. Helens, Washington.
“Thousands could have perished if not for the persistence of [Johnston and] a team of scientists and law enforcement and emergency officials,” wrote Melanie Holmes, author of A Hero on Mount St. Helens.
At the time St. Helens erupted on May 18, 1980, Johnston was stationed about five miles away from the summit, monitoring the volcano at a makeshift observation post. About 8:30 a.m., a substantial earthquake centered below the north slope resulted in a volcanic blast that could be heard hundreds of miles away. The largest landslide in modern history immediately made much of the summit’s north face vanish.
“Vancouver! Vancouver! This is it! This is it!” Johnston screamed into a radio with a final warning directed towards that nearby Washington city where his USGS unit was based. Then he perished in the blast of hot, molten rock and other materials that traveled more than 220 miles per hour.
His body has never been recovered. In 1993, state highway workers found remnants of his trailer.
Advances in predicting eruptions
Harry Glicken, a USGS volcanologist who was mentored by Johnston, is the only other U.S. volcanic scientist to die in an eruption. He passed away in 1991 while monitoring a blast at Mount Unzen in Japan. Glicken took the last photo of Johnston at the St. Helens post after the older man relieved him.
Today, the area around Mount St. Helens has regrown in many areas, though patches are still bare. Many aquatic creatures, insects, and animals sleeping underground during the blast benefited from the ash. Trees and plants, with some species new to the region, sprouted up. Life continues, but it’s not exactly how it was before the natural explosion.
At a visitors center about 52 miles west of the volcano, an employee noted that St. Helens has gone through lengthy periods of dormancy, with the previous major eruption before 1980 in 1857. Smaller blasts occurred as recent as 2008. It wasn’t “too bad” to live near a volcano, she said. “You just have to be able to run fast.”
Other volcanoes in the region could be due. Mount Rainier last erupted in 1894, Mount Hood in 1866, and Mount Adams in 950. In Hawaii, Kilauea erupted last January. On May 22, the Hawaiian Volcano Observatory reported that magma was accumulating underneath the surface, that Kilauea was showing signs of “heightened unrest.”
Barb, a St. Helens volunteer originally from Delaware, heard the 1980 blast while living in Seattle 160 miles away. “It’s a beautiful area,” she said, while hiking along a trail outside the visitors center. “I remember hiking closer to the summit in 2004 when there was a mini-eruption. There weren’t any signs warning people to stay away. But for a moment, I thought, ‘Okay, this is it’.”
At the Johnston Ridge Observatory, which opened in 1997 at the site where Johnston perished, visitors learned about the stories that day through exhibits and a film. But the main draw was the eerie summit that loomed a few miles away, its craters hiding secrets of the dead and the living and an enormous, mysterious power of nature.
Most threatening volcanoes in the U.S.
While Popocatepetl is certainly the most threatening volcano right now in North America, Kilauea is another being closely monitored by volcanologists. The USGS scores volcanoes in the U.S. and its territories according to their potential threat of major eruptions, giving Kilauea the highest score of 263 in its last survey.
St. Helens is the second most threatening volcano in the U.S., with a smaller eruption as recently as 2008. Rainier is third, followed by Mount Redoubt in Alaska, Mount Shasta in northern California, and Mount Hood in Oregon.
Among the least threatening volcanoes not in the far western Pacific states are Dotsero in Colorado [49 score], Craters of the Moon in Idaho [14], and Carrizozo in New Mexico [6].
Most threatening volcanoes in U.S.
Name/ State…Threat score.. Last eruption
1. Kilauea, Hi… 263… 2023
2. Mount St. Helens, Wa… 235… 2008
3. Mount Rainier, Wa… 203… 1894
4. Mount Redoubt, Ak… 201… 2009
5. Mount Shasta, Ca… 178… 1250
5. Mount Hood, Or… 178… 1866
7. Three Sisters, Or… 165… 440
8. Mount Akutan, Ak… 161… 1996
8. Mount Makushin, Ak… 161… 1995
10. Mount Spurr, Ak… 160… 1992
11. Mount Lassen, Ca… 153… 1917
12. Mount Augustine, Ak… 151… 2006
13. Newberry Volcano, Or… 146… 690
14. Mount Baker, Wa… 139… 1880
15. Glacier Peak, Wa… 135… 1700
16. Mauna Loa, Hi… 131… 2022
17. Crater Lake, Or…129… 2800 B.C.
17. Long Valley Caldera, Ca…129…98000 B.C.
21. Yellowstone Caldera, Wy…115…68000 B.C.
34. Mount Adams, Wa…92…950
44. Mount Pagan, NMI…79…2021
46. Great Sitkin, Ak… 76 …2023
55. Semisopochnoi, Ak...70…2023
Source: U.S. Geological Survey
Kevin Shay is a journalist and author of several books, including the travelogue-memoir, It’s a Mad, Mad, Mad, Mad Trip.
