How a Graham farm helped detect a swarm of earthquakes at Mount Rainier

Outdoors at a Graham farm and enclosed within a small padlocked gate for protection from meddling cattle, an antenna mast roughly 12 feet tall stands behind a weathered equipment-cabinet and a silver box covered in spider webs.

The curious trio of items, including the technical instruments inside the cabinet, are of no use to the property’s owner, but they do serve an important purpose.

The tiny site in rural Pierce County is one of roughly 650 seismic stations operated by a local organization across the Pacific Northwest to detect and monitor earthquakes in the region. When Mount Rainier experienced a rapid succession of small temblors this summer — the volcano’s largest “swarm” ever recorded — the farm’s station was a key contributor to recording that activity.

“Ultimately, people understand, to do the science, we need the equipment somewhere,” Doug Gibbons, a field technician and seismology lab coordinator for the Pacific Northwest Seismic Network (PNSN), told The News Tribune recently.

The organization, which runs the stations and monitors earthquakes and volcanic activity in Washington and Oregon, is jointly operated by the University of Washington, the University of Oregon and the U.S. Geological Survey’s Seattle Field Office. It’s the second-largest seismic network in the country, according to PNSN’s website.

While the researchers rely on the network of stations to track earthquakes, they equally depend on public and private participants to create the system by hosting the necessary equipment in outdoor and indoor settings far and wide to improve detection time and accuracy. That means that schools, fire stations, private property owners and others are counted upon, like some federal and state agencies, to keep PNSN’s equipment in boxes, cabinets, or both, on their property. There’s no compensation.

“I think that’s a cool part of the story that sometimes gets missed,” Gibbons said, “that there’s these citizens and other groups — that we couldn’t do this monitoring without them.”

Most of PNSN’s seismic stations are on private lands, schools, U.S. Forest Service property, timber company lands or at fire departments, according to data provided by the organization.

The number of stations between Washington and Oregon has more than doubled over the past seven or so years to coincide with implementation of the ShakeAlert Earthquake Early Warning System, managed by the USGS, Gibbons said. As part of that ongoing effort to provide public alerts potentially seconds before strong shaking begins during a significant temblor, experts identified coverage gaps in monitoring areas and therefore good locations for new seismic stations.

“Then, it was knocking on doors,” he said.

A signal from Mount Rainier

Garrison Hill, as the station on the farm in Graham is known, predates the ShakeAlert program. More than an hour’s drive northwest from Mount Rainier, the station was put into place in 1975, according to Gibbons. He visited the site with The News Tribune on Sept. 11 when he took scouting photos for a planned upgrade. The station’s host, who didn’t wish to be interviewed, provided the customary permission to enter the property.

Beyond allowing a station on their grounds and providing power and internet, hosts aren’t involved in any of the work performed by the PNSN. Site visits occur typically every five years or as needed for maintenance, according to the organization. Stations use power equivalent to a small light bulb, if not solar power, and about 0.2% of a standard home’s internet bandwidth, the group says.

Each station costs about $20,000 to $30,000 and is funded by the USGS, with small contributions from Washington and Oregon, according to Gibbons.

Garrison Hill is unique in that it not only records nearby earthquake data but also transmits data it receives by signal from STAR, one of three main stations up high on Mount Rainier, to PNSN’s server room at the University of Washington, Gibbons said.

Between early July and late August, more than 1,350 earthquakes too small to be felt were located at Mount Rainier, and thousands of others there were too small to be pinpointed, according to the USGS’ Cascades Volcano Observatory. CVO studies and monitors volcanic activity and maintains federally operated stations on volcanoes that read seismic activity. It works closely with PNSN.

The swarm of temblors, which made national headlines, dwarfed the active stratovolcano’s monthly average of roughly 10 earthquakes. There had been no cause for concern, however, that Mount Rainier was on the verge of eruption — something that hasn’t occurred in about 1,000 years, observatory officials said.

During the swarm, researchers were receiving around-the-clock waveform data. The STAR station was instrumental in beginning to recognize the start of the barrage, and Garrison Hill transmitted STAR’s data to the university, according to Gibbons. Together, STAR and two other main stations up high on Mount Rainier were key in calculating the depths of the earthquakes that were occurring, he said.

Without Garrison Hill, which is the only data pathway for STAR, there would be no way to obtain the information that STAR was recording, although Gibbons said plans are in the works to fix that.

Raising awareness

After leaving Garrison Hill in mid-September, Gibbons traveled to Tehaleh Heights Elementary in Bonney Lake. A classroom there leads outside to a courtyard, where a 20-inch-by-20-inch silver box sits just beyond the edge of pavement, next to a tree and partially obstructed by a blue picnic table.

In indoor stations, also known as urban stations, only the box and a small GPS antenna are needed, according to PNSN. Tehaleh Heights Elementary, which has hosted the equipment since 2021, is considered an urban station even though its box is located outdoors, enclosed by school buildings.

The school, which is as close to Mount Rainier as any of PNSN’s urban stations get, was a fitting location for researchers’ educational aims. Gibbons said PNSN was working with Washington state to try to develop earthquake curriculum.

“They do wonder (what the box is) when they’re out here,” principal Jennifer Knight said of students, noting that she also saw the possibility of using its presence as an educational tool.

Young pupils aren’t alone in sometimes being puzzled by the sight of the box, which requires about 4 square feet of space and maintains interior instruments protected by a lock. The box itself has a fairly unremarkable appearance. On some occasions, public hosts have inquired about its existence, usually after years have passed since the host signed a land-use agreement with PNSN to house it and leadership had changed, according to Gibbons.

“There’s this silver box in your closet and they say, ‘Oh, that’s what that is,’” he explained.

Someone stacked a popcorn machine onto a seismic station in a Gig Harbor school’s closet, according to Gibbons. At the Boeing Fire Department, one is tucked away near CPR dummies.

Gibbons said PNSN has recognized that spreading brand awareness is key to earthquake advocacy and education, but it’s also important for the organization to show it is doing good work amid recent budget uncertainty.

After enacting layoffs at the USGS earlier this year, the Trump administration proposed shrinking the agency’s funding in the fiscal year 2026 budget, including $60 million in cuts to its Natural Hazards Mission Area. The proposal maintained funding for core national earthquake monitoring and reporting capabilities, according to Congress.gov.

The USGS, Department of Interior and White House’s Office of Management and Budget didn’t respond to inquiries seeking to discuss the proposed budget.

Democratic Rep. Kim Schrier, who represents the 8th Congressional District where Mount Rainier is located, said in a statement in late July that she would continue to fight the administration’s attempts to undermine federal services relied on by the public.

The swarm had been “a reminder to all of us of just how fortunate we are to have earthquake monitoring systems and volcanic activity monitoring systems, both supported by the USGS,” Schrier said. “This is particularly true in the 8th Congressional District, where students in the communities surrounding Mt. Rainier do lahar evacuation drills every year.”

What’s that noise?

When earthquake-tracking equipment is on farms, in forests or at other outdoor properties, there’s always a risk for damages. About half of PNSN’s outdoor stations, known as rural stations, are buried three-to-10 feet underground in vaults below the surface. Cable-chewing elk, brush fires and downed trees have caused issues for above-ground sites, Gibbons said. Vandalism is rare, however. PNSN seeks to keep rural stations in open fields or animal pastures and away from human activity in order to best detect faint vibrations from distant earthquakes.

The instrumentation — including sensors, electronics and a backup battery — is sensitive but also capable of filtering out extraneous noises, whether that be from wind, trains, cars, cows or dozens of playful school children. Spikes in waveform data at one station must also be seen at many others or else PNSN’s system will assume the cause is simply local energy, according to Gibbons.

As an example of that local noise, Gibbons performed a stomp test in Tehaleh Heights Elementary’s courtyard. It’s one of the final tests to ensure a station works after one is installed, but it also enables researchers and onlookers to view waveforms reacting to the ground-banging basically in real time on a laptop computer.

“Let’s see what (waves) 140 kindergartners make,” Knight said, with a laugh.

All activity data from PNSN’s seismic stations are publicly available and can be viewed online at https://pnsn.org/seismograms/map.