Working in Clark County: Weston ‘Wes’ Thelen, seismologist at USGS

It’s safe to say that the list of jobs out there that might require hiking around a volcano is a short one.

Since Clark County sits in the shadow of several of the most dangerous volcanoes in the United States, a small concentration of those jobs can be found here in Vancouver – where the U.S. Geological Survey made a home for the Cascade Volcano Observatory, the largest of the agency’s five observatories within its Volcano Hazards program.

Weston “Wes” Thelen, a research seismologist, is one of 68 volcano hazard employees at the Vancouver location. And although he’s worked from his Fisher’s Landing East neighborhood home for the last year due to the pandemic, he’s regularly hiking miles, often in the snow, around Mount Hood and Mount Rainier to check on the monitoring stations that are in remote areas far from any hiking path.

“For the past couple years, I’ve been the science lead on Mount Rainier’s lahar detection system,” Thelen, 40, said. A “lahar” is a term scientists use for dangerous mudflows that surge far beyond a volcano after an eruption. Should an eruption happen, the hot lava would melt huge quantities of snow and ice, creating the lahars, which pose a threat to communities near these active volcanos.

Mount Rainier has a history of these mudflows, as recent as 500 years ago, Thelen said.

“These all have a low probability of happening. In the next 30 years, there’s a much higher chance of the ‘Big One’ (earthquake) happening offshore than there is of a lahar coming down one of these drainages,” Thelen said. (Some scientists said there’s about a 14 percent chance of the Big One happening in the next 50 years.) Nonetheless, there’s still a chance of a lahar, so the agency is using federal funding to develop a warning system for the Mount Rainier area.

And while the job takes him out on the mountains, his job also is to write.

“I do research on things in the Cascades and elsewhere. If there’s interesting signals, we might use those signals to write a paper. I want to know. I want to study things that impact our ability to forecast the next eruption, wherever it is,” he said.

When the pandemic hit, Thelen had to move this project development to his home. The observatory office is still closed to nearly all employees, and upper management is mulling how to move forward, according to the observatory’s scientist-in-charge, Jon Major.

But that just meant that Thelen got to turn his garage into a “test bench” for the high-tech gadgets used by scientists that do things like detect infrasound – sound that’s generated below the ground that would help alert us to dangers like an avalanche, debris, mud flow or explosions.

Permit pending from Mount Rainier National Park, Thelen is hopeful that they will be able to install nine stations to help detect a natural disaster.

“That’s been taking up a lot of time. It’s a big project and it’s important. It’s not easy … there’s not really another system out there to base this on,” he said.

It’s also not easy because plopping stations down in the wilderness requires cooperation and agreement between the public and other federal agencies. Their original proposal, Thelen said, wanted 12 stations, but after a public comment period in the fall of last year, it was reduced to nine. Thelen is awaiting more feedback on the proposed monitoring stations following a yet-to-be-announced public comment period this spring.

The challenges installing the stations at Mount Rainier echo the challenges of installing stations at Mount Hood, as documented in a 2019 New York Times story.

“We’ve already benefitted from the presence of those stations. We recorded avalanches that we wouldn’t have before,” Thelen said.

They were controversial at Mount Hood, he said, because they were on land protected by the Wilderness Act. He said six of the nine proposed stations at Mount Rainier would be impacted by the act, which protects land from having any man-made structures unless there’s a “really good reason.”

Thelen said he loves the wilderness as much as anyone – growing up just outside of Lake Tahoe, he spent his childhood skiing, climbing, hiking, camping and “taking in all of the things the mountains had to offer.”

That interest landed him at the University of Nevada and later the University of Washington, where he studied for his doctorate. Thelen started there in 2004, about a month before the most recent eruption of Mount St. Helens and used that as a focus for his dissertation. After working in Hawaii – another state ripe for volcano study – for five years, he moved back to the Pacific Northwest in 2016.

He says maintaining the balance of safety and love of the wilderness is tricky.

“I love there’s these big areas where there’s not going to be any motorized vehicles or (man-made structures). On the other hand, we really need to have stations close to the volcano to see the small signals that may be the first clue that unrest is about to happen,” Thelen said.

Regarding unrest, he expects another eruption of Mount St. Helens similar to 2004 to happen in his lifetime. Whether or not Mount Hood or Rainier will spew lava isn’t as likely, but it’s possible.

“It’s funny. We talk about forecasting eruptions a lot, but we aren’t like weather people on the TV,” Thelen said. “We don’t have these satellite shots overhead of a storm that’s coming off the Pacific, about to hit us in a week or two. Instead, we get these really fuzzy images inside the volcano.”

Seismology technology is improving, and Thelen pointed to the evolution of cellphones since the 1990s. The stations they install for monitoring currently “hold batteries and electronics more or less the size of a larger desk,” he said. The ones proposed at Mount Rainier are something like a hut, about 9 feet tall, extending up to 12 feet high.

“We’re getting better battery tech. That allows us to put things in that are smaller and have less impact, but also, we’re able to put more in. Even in a temporary sense,” Thelen said. “If we can get sensors out there quickly and get 100 out just for a month, that’s where I think the science is going.”