February 24, 2024
The next big earthquake. A perilous wildfire season. California definitely has its share of potential disasters – but one you might not normally think of are volcanoes.

The next big earthquake. Wildfire perils. Steph Curry breaking both ankles simultaneously. California definitely has its share of potential disasters – but one you might not normally think of involves volcanoes.

Give Andy Calvert a few minutes, and maybe he can change that. Calvert is the scientist-in-charge at the California Volcano Observatory in Menlo Park and Moffett Field, a U.S. Geological Survey facility that studies local volcanoes. Yes, they exist: The early-1900s eruption of Lassen Peak devastated the surrounding region and spread ash all the way to Nevada. Eruptions around Mono Lake and Mammoth Mountain occurred relatively recently between 300 to 600 years ago, and Mount Shasta went off about 3,000 years ago and is very capable of a repeat.

“All of these volcanoes will erupt again. Whether it’s in our lifetimes or not is uncertain,” says Calvert. “It’s not something all Californians need to worry about, but it is important enough to fund scientists to keep an eye out. We’re keeping an eye on it, so you don’t have to, really.”

Calvert found time in between the things researchers do at the observatory – collecting samples, setting up ground instruments, torturing rocks with high heat and pressure at a magma-dynamics lab – to chat about the explosive forces lurking below our feet.

Q: How did you get into this field?

A: I grew up in a small town called Moscow, Idaho. We were hundreds of miles downwind of Mount St. Helens when it erupted in 1980. I was in seventh grade and an inch of ash fell on my front porch, and they canceled school for the rest of year. So I like to say, I’m paying the earth back for getting me out of seventh grade early.

Tthe first rock sample I ever collected was that ash from my front porch. I’ve still got it on my desk – it’s a really fine gray powder, like flour. That eruption was really what taught me the earth was a dynamic place, and it was interesting to study because it’s not just a static background.

Q: That eruption in Washington caused more than $1 billion in damages. Would the economic toll be similar for a California eruption today?

A: I think a billion dollars would be very conservative. Volcanoes, for the most part, are kind of where people aren’t. Like Mount Shasta, they’re scattered on the edges (of major civilization). But they are right next to freeways and some towns. And when they erupt they make a pretty big mess. Mount St. Helens produced about 1 cubic kilometer of material, and they’re actually still dealing with it.

Andy Calvert, Scientist-in-Charge of the California Volcano Observatory, holds a jar of ash from the Mount St. Helens eruption that he collected from his home in Idaho when he a teenager, in his office at the United States Geological Survey in Menlo Park, Calif., on Monday, Aug. 1, 2023. (Nhat V. Meyer/Bay Area News Group) 

Q: What are the hotspots for volcanic activity in California?

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A: Three are way up north – Mount Shasta, Medicine Lake Volcano and Lassen Peak. North of the Bay Area, there’s Clear Lake and (to the east) the Long Valley caldera with Mammoth Mountain and Mono Lake. To the south, there’s the Coso Volcanic Field near the Mojave, and then Salton Buttes next to the Mexican border. Those are the “eightish” ones we really actively monitor.

Q: How often does California get an eruption?

A: It’s not like clockwork. These are independent systems that work on their own time scales. But we’ve had about 10 significant eruptions in the last thousand years, so perhaps one on the order of every 100 years.

Q: And where will the next one be?

A: The next one? Oh, here we go. I think most likely it’d be one of two places: somewhere up near the Lassen volcanic field again or, more likely, near Mono Lake in that US 395 corridor. There are some very young, explosive Mono craters. That eruption very likely would go on between one and six months, with some explosive periods that would put a lot of ash into the air. We’d have to divert airliners around it.

Q: Would that affect many people on the ground?

A: Well, the town of Lee Vining is next to Mono Lake, and south there’s the town of Mammoth Lakes that has maybe 7,000 people year round – but there could be 25,000 people skiing on a busy day. In fact, in the 1980s, there was a lot of worry about an eruption in Long Valley next to Mammoth Lakes. There was enough ground deformation, people got pretty nervous and housing prices dropped. But nothing ever happened and the magma stayed in the ground – that’s what we like to call a “failed eruption.”

Q: If a volcano blows tomorrow, what immediate effects can we expect?

A: Say we pick Mount Shasta. If it actually blows tomorrow, it probably would’ve told us it was happening over the last two months or so. We would’ve been feeling earthquakes and seen ground deformation – we watch by satellite and have GPS instruments on the surface. We would’ve been in contact with CAL OES and the forest service and local sheriffs, and would’ve developed a plan to get people out of the way.

Q: That’s important, but not very sexy. Can we talk about the mayhem?

A: A typical eruption at Mount Shasta would probably start near the summit. The groundwater would be heated by rising magma, there’d be explosions of old rocks and then when the eruption came, we’d have a pretty big ash plume. There’s a lot of ice on Mount Shasta, so if lava got close to that, it’d melt catastrophically and create large mudflows to cause quite a mess with roads and railroads.

Q: Railroads?

A: Yeah, the railroads run right along the edge of Mount Shasta and a lot of freight moves through there. The lowlands would be inundated, and it would very likely take out the highway and the trestles the railroad goes over. There’s also a lot of hydroelectric power we use in California that comes down from Oregon and Washington. Those high-voltage lines over Mount Shasta and Medicine Lake. And then the natural gas pipelines – those go over our volcanoes in Northern California, too. So there is the real opportunity for a lot of our infrastructure being impacted.

Q: Why would we worry about electric lines?

A: When you put ash into humid air, it creates this rain that’s like mud falling out of the sky. That will stick to the insulators, and they can arc and short. We’ve actually seen this happen in other countries.

Q: What if California gets hit by a volcanic eruption and major earthquake at the same time – has anyone ever run scenarios for that?

A: Yeah, we do talk about cascading events.

Q: Really?

A: The chances of having a large volcanic eruption and a significant earthquake in the same place are pretty small. But it would be a tremendous challenge. The key is to listen to authorities and evacuate when you need to. Just like with earthquakes or floods, you want to have a plan, have some food and water to deal with natural disasters — because they’re going to happen.

Andy Calvert, Scientist-in-Charge of the California Volcano Observatory, sits on a rock from the eruption of Mount Saint Helens, May 18, 1980, outside of his office at the United States Geological Survey in Menlo Park, Calif., on Monday, Aug. 1, 2023. The rock is dedicated to David Johnston, a 30-year-old volcanologist with the USGS who died during the eruption of Mount St. Helens. (Nhat V. Meyer/Bay Area News Group) 

Andy Calvert

Age: 56
Position: Scientist-in-Charge at the California Volcano Observatory, U.S. Geological Survey
Education: Ph.D. UC Santa Barbara, M.S. and B.S. Stanford University
Residence: Belmont, Calif.
Family: Andy and his wife, Amy McLanahan, have two children

Five things about Andy

1. He enjoys hiking and skiing
2. He’s visited more than 50 volcanoes in the U.S., New Zealand, Italy, Saudi Arabia, Guatemala and elsewhere
3. Despite how fun it sounds, he’s never thrown anything into an erupting volcano: “I think that’s frowned on.”
4. His favorite disaster movie is “Dante’s Peak”
5. In regard to what position he’d like to be frozen in a la Pompeii: “It wouldn’t really matter to me, because I’d be dead.”

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