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Cascades Volcano Observatory is keeping an eye on Northwest volcanoes

As scientist in charge of the Cascades Volcano Observatory, Seth Moran monitors volcanic activity in the Pacific Northwest. If you live here, you should, too.

Moran and his staff of about 35 people can help with that. Based in Vancouver, Wash., the Cascades office — one of five regional observatories operated by the U.S. Geological Survey to monitor volcanoes — issues a weekly update every Friday on volcanoes in Washington, Oregon and Idaho. They also share information on the USGS Volcanoes Facebook page and Twitter feed.

“There’s a variety of ways for people to tune in and find out what’s going on,” Moran said.

Life in the Pacific Northwest means living with active volcanoes whose activity could affect residents near and far. The Northwest has eight of the highest volcano threats in the United States, he said. “That’s an illustration of the importance of the work we’re doing,” Moran added.

When Mount St. Helens erupted on May 18, 1980, wind-borne ash turned daytime Yakima County into night, coating everything in its path and interrupting regular daily activities for weeks. The eruption wasn’t a surprise, but its deep impact on distant Yakima was unexpected, Moran said.

“People in Yakima ... got really hit with ash. That was something that turned out to be a bit of a weakness in the whole preparation side of things,” he said. In preparing for the eruption, “there was a lot of concentration on communities around (Mount St. Helens) and on the West Side.”

Mount St. Helens is up to its usual activity these days and has been for a while, so there’s nothing to worry about right now. The most recent email sent Friday said the volcano alert level in the Cascades range is normal, meaning Mount St. Helens and its sister volcanoes being monitored by observatory staff are at normal background levels of activity.

The office monitors Mount St. Helens, Mount Baker, Glacier Peak, Mount Rainier and Mount Adams in Washington and Mount Hood, Mount Jefferson, Three Sisters, Newberry and Crater Lake in Oregon.

“Normal background levels” mean the volcanoes are in a noneruptive state, according to the observatory’s website.

The weekly updates often include brief recent observations. Over the past week, small earthquakes at Mount Rainier and Mount St. Helens were consistent with normal seismicity levels at each volcano, the May 8 email noted.

Normal does not mean the volcanoes are doing nothing. They show signs of activity in one way or another, such as earthquakes and emissions, Moran said.

“Since 2008 it’s been that way. Normal includes some variation in activity. Mount St. Helens has a fairly high background rate of earthquakes. There are times that rate increases (to) 15 to 20 a day,” but that’s still within the normal range of variability, Moran said.

“Mount Rainier has earthquakes, not as frequently as Mount St. Helens — a couple a week,” he added. “In a three-day time period in 2009, we recorded over 1,000 earthquakes. It petered away.”

It’s clear from a closer look at Mount St. Helens that it’s still an active volcano. Though not nearly as dramatic as the May 18, 1980, eruption, the mountain’s continuous expulsion of magma in low-key yet steady activity from 2004-08 is considered an eruption. It began with a brief series of small steam-and-ash explosions, as described on in a Cascades Volcano Observatory summary. The material that came out then, and steam today, is enough to keep the crater relatively snow-free.

And in 2014, the observatory issued an information statement when staff were gradually seeing “very subtle” signs the Mount St. Helens system was starting to recharge, Moran said. Those signs included stations on the GPS network moving slightly, along with deeper earthquakes.

“(This) made us believe it was getting itself ready for the next eruption. But that next eruption is years to decades down the road,” he said. “That’s the best we can do at this point.”

These volcanoes might be slumbering, but with one eye open. “We still need to pay attention (so) we and everyone else are ready for the possibility they can erupt,” Moran said.

Mount St. Helens’ threat potential in particular remains “very high,” as the Cascades observatory notes on its website. It remains among those with highest priority for monitoring in the National Volcano Early Warning System.

“It’s got more magma coming into it than other systems,” he said. “We have to keep our eye on the prize. When the volcano has gone up in 1980 and 2004, it has gone really fast.”

About 70 people normally work at the Cascades Volcano Observatory and related offices in Vancouver. Half that number concentrate on the Cascades; the rest work for the Volcano Disaster Assistance Program and the four sister USGS volcano observatories. Some of their staff works in Vancouver, Moran said, along with an administrative group that provides support for all the volcano observatories.

The coronavirus pandemic has quieted the offices, but crews still visit field stations as needed. Staffers maintain monitoring networks and analyze data through telework and other adaptations.

“There’s a variety of ways we can look at things. When I moved down here in 2003” from Alaska, “we were just at the cusp of being able to do some of that job at home,” Moran said.

At this point, Cascades Volcano Observatory would be getting ready for field season, Moran said. Staff are working toward that, but ramping up more slowly to determine how to best do their jobs safely and maintain social distancing.

“We almost always work in groups, for safety reasons,” he said. “And there’s a lot of different reasons for going out in the field for monitoring. ... We have an active mapping project in Glacier Peak. That’s a volcano that has had some decent eruptions in the last 10,000, 15,000 years. People (working) at Mount Hood, Mount St. Helens, Mount Rainier — that will continue with some precautions.”

The observatory also produces volcano hazard maps, which are used by land management agencies and emergency managers for preplanning and evacuation drills, for example.

“The hazard maps are a really primary talking point for making it real. In a scenario like a 1980 eruption, there’s the area that could be impacted by that,” Moran said. “We also have fact sheets of each volcano, which are four to six pages, in fairly plain language — what’s happening at the volcano ... what their story is.”

And then there’s “rumor control,” which is important for several reasons.

“This happens with Mount Adams. (People) see a dark spot; they see an odd-looking cloud and they want to know what’s going on. We’re able to tell them that,” Moran said. “It’s not just sitting around waiting for the next volcanic eruption. It’s also reports of what people are seeing and chasing that down.”

For future (or current) reference, that number is 360-993-8973.

The stunning Pacific Northwest landscape is the result of a geologically active area. “It’s good to be aware of that and good to be aware of how you would deal with” something like Mount St. Helens, Moran said.

“Understanding the hazards and knowing how to deal with (volcanoes) is important (so) you can roll with the punches when they come.”

Reach Tammy Ayer at or on Facebook.

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