Volcano Researchers Take to the Field in Lassen Volcanic National Park

MIDDLEBURY, Vt. – Lassen Volcanic National Park’s Cinder Cone looks like a kid’s science project volcano gone large, a perfectly conical pile of volcanic rubble rising 750 feet high.

“Cinder Cone is amazing because it’s perfect,” said Middlebury volcanologist and assistant professor of geology Kristina Walowski. “It looks like it hasn’t been touched since it erupted in 1666. And a big part of that is just the climate in the region. It’s very arid. If the exact same cinder cone, for example, was in Costa Rica it would just be a pile of mud covered in a jungle.”

Walowski began her summer field research in the Lassen region by hiking her crew up to Cinder Cone’s double-rimmed summit to get them seeing volcanoes with new eyes.

“When you look out from Cinder Cone,” said Walowski, “every peak, every little bump in every direction is a volcano. All the topography you see is volcanoes that have erupted over the past 20,000 to 50,000 years. And you really get the sense for what a volcanic landscape is like.”

Looking out from Cinder Cone, there’s almost no vegetation as far as the eye can see—save for the Jeffrey pines poking up here and there amidst scrubby banks of manzanita. To the east the aptly named Fantastic Lava Beds spill out almost three miles in an arc between two lakes, the pathways of the once molten lava now etched in stone. Ten miles off in the distance rises Lassen Peak, the southernmost volcano in the Cascade Range and, like Mount St. Helens, its sister to the north, one of only two volcanoes in the contiguous United States to erupt in the 20th century. Indeed, the Cascade Volcanic Arc (which includes Lassen Peak, Mount Shasta, Mount Hood, and Mount St. Helens and stretches from Lassen Peak north into British Columbia) is part of the Pacific Ring of Fire and one of the most volcanically active regions in North America.

For Walowski, the view from Cinder Cone is “a great teaching moment… . Nothing compares to seeing geologic process or features in the field. It really helps solidify what a volcano is to students when I just take them to Cinder Cone. It changes the framework in which they think about the science they’re doing when they can stand on top of the volcano and see it.”

Dominating the view from Cinder Cone, said Walowski, are more cinder cones, a primary focus of her current research and one of four main types of volcanoes.

Elle Simmons ’21 hikes the rugged terrain in Lassen Volcanic National Park in California.

When most people think “volcano” they typically picture one of the superstar stratovolcanoes, like Mount Fuji, Mount Vesuvius, or Mount St. Helens. “Cinder cones aren’t as glamorous as stratovolcanoes because they aren’t these gorgeous, huge mountains with super exciting, intense eruptions and glaciated peaks,” said geology major Elle Simmons, a rising sophomore and one of Walowski’s summer research assistants.

“Even scientists have become overly fascinated by them,” said Walowski, of stratovolcanoes. “So I found it really interesting that there were still a lot of holes in the science of cinder cones, especially in California.”

Cinder cones are created when magma is ejected explosively, rather than flowing out as lava. The ejected magma cools rapidly while traveling through the air and lands on the ground as solid matter. This particulate, also called “cinders,” “scoria,” or “tephra,” can range in size from ash particles to large boulders. Lava can flow out from cracks at the base of a cinder cone during the eruptive phase, but doesn’t make up the cone itself. Geologists describe cinder cones as “monogenetic,” meaning that they are created out of a single eruptive source or event, which can extend over months or years. Typical would be Mexico’s Paricutin. On February 20, 1943, the earth swelled up and split open in the middle of a cornfield and ash began spewing out. By 1952 when Paricutin went dormant, what was once cornfield was now a 1,391-foot-high pile of cinders.

“One of the reasons that Kristina and people who study monogenetic volcanoes are really interested in them,” observed research assistant Sam Kaelin ’19.5, a geology major, “is that they represent a purer expression of the mantle inside the earth, and that’s what she is really interested in—the basic chemistry and functionality of how the earth works.”

Sam Kaelin ’19.5 collects samples during a field research trip to Lassen Volcanic National Park.

This summer Walowski is continuing research on two smaller cinder cones just to the north of the national park’s boundaries. Her overall goal: “to understand how and where the magma was stored, evolved, and tapped prior to eruption.” Her approach combines “physical volcanology” (looking at shapes, physical features, and processes of formation, such as fluid dynamics), and “geochemistry” (analyzing the chemical makeup of the rock itself).

For example, at the site called MBX (for its moniker “Basaltic Andesite of Box Canyon” on the geological map), Walowski is interested in the temperature, pressure, and depth from which the magma exploded. One key to this information can be found by analyzing the chemical composition of the mineral clinopyroxene in tephra and lava samples. Walowski had gathered samples during earlier field trips to MBX and is at work on a research paper coauthored with recent Middlebury graduates, but wants more samples to make sure that the data is as robust and complete as possible. So this summer she and her crew gathered more samples to take back to the lab. She’s also using the samples to further decode the site’s topography and determine how the small valley at the MBX site itself was shaped.

Fieldwork has its grungy side, says Walowski: “It’s being in the sun. It’s hot. It’s strenuous. It’s a lot of hiking, hammering, digging.” But it also brings a kind of joy and builds a unique camaraderie. Walowski credits her own undergraduate fieldwork experiences—looking at volcanic landscapes in California’s Owens Valley—as a huge part of why she became a geologist, and she loves introducing a new generation of students to the rigor and joys of that experience.

Now back in the lab in Bicentennial Hall at work prepping samples, both Kaelin and Simmons feel that a huge part of the richness of being summer research assistants was simply working side by side with Walowski in the field.

“The beauty, not just of Middlebury’s Geology Department but the sciences as a whole, is that I—a 19-year-old undergraduate student—can conduct research that could actually impact a field and discover things that have not been discovered before and contribute to a deeper understanding of geological processes,” said Simmons. “I feel like that’s not something that many people get to experience, so when I was offered this research position I was beyond excited just because of the impact of it all.”

And then there’s the joy of being in nature 24/7.

“I love being outside and I love exploring. I just love it,” said Kaelin, who’s also a guide with the Middlebury Mountain Club.

Simmons said she started college thinking she hated science but took geology in her second semester and was electrified by it. Kaelin had been pursuing computer science while taking geology classes and realized after going on the 2018 J-term geology trip to Costa Rica that he had found the thing that truly excited him.

The students concurred that you know you’ve found the right thing when “you get to that point that you start talking to your friends about the things that you’re learning and they don’t care—you can tell that they don’t care—but you like it so much that you just keep talking.”

Still, the Lassen research also brought home the lesson that field research definitely has its challenges.

When Walowski and crew arrived at their base camp in late July, they opened their car doors to a smoke-filled sky. Four days earlier, sparks from a tire failure on California Route 299 had set off one of the most destructive fires in California’s history. The day before they arrived, the fire jumped the Sacramento River and forced the evacuation of parts of Redding—roughly 60 miles west of their campsite near Butte Lake.

Kaelin, who will begin his senior research project this fall, had planned to identify his own cinder cone site in the Lassen area, with the goal of studying its explosivity and creating an isopach map to show the inner and outer reaches of the exploded particulate. With Walowski’s help, he’d narrowed down the candidates before arriving at Lassen. But a first day of digging at potential sites had turned up muddled layers and tephra that crumbled like dirt in his hand—not the clear stratification and hard volcanic chunks he needed for his analysis.

As the smoke thickened and the group learned of a second fire 30 miles east and decided to decamp, Kaelin realized he had to adjust his fieldwork goals quickly. Fortunately, Walowski knew of a quarry right off a logging road where there was a good exposure of the tephra with easy access, from a cone still relatively unstudied. Kaelin gathered the samples he needed and they hurried out of town.

“I was personally super bummed right away when things didn’t work out exactly as I’d hoped,” said Kaelin. “But Kristina was like, ‘This is the way that field science works. You plan and you come up with an idea and you come up with a question and you go out there and you try—and it’s not always going to be perfect.’

“Everything’s not a textbook example like Cinder Cone,” Kaelin continued. “You get out there and there’s trees and there’s soil and there’s smoke and there’s human interaction and you have to adapt to those things and you have to alter your questions and your understanding based on what you’re finding.”

By Gaen Murphree; Photos by Todd Balfour, Kristina Walowski