Seismic citizens: Volunteers host home-based seismometers to help assess earthquake threat
Copyright iStockphoto.com/Mark Hatfield
Courtesy of Doug Gibbons
Copyright Erik Stuhaug/Seattle Municipal Archives, Creative Commons Attribution 2.0 Generic
Copyright J. Johnson and Harvey Greenberg/University of Washington Department of Earth and Space Sciences, Creative Commons Attribution 3.0 Unported
John Hamilton, U.S. Geological Survey
Copyright iStockphoto.com/Nancy Nehring
Lisa Hayes is a proud parent of three — oldest son Caleb Quinn, grown and out of the house, “Bubbins,” a pajama-clad tot whose toys litter the living room floor, and QUIN, a healthy, 15-pound, blue metal box named for his brother. The latter joined the family in the summer of 2010 and lives in the basement, where Hayes occasionally checks up on him. “I love QUIN,” she says.
Adding QUIN to her family also brought Hayes into another family of sorts: a network of volunteer hosts and home-based seismometers around Washington’s Puget Sound region that reports earthquake data to the U.S. Geological Survey (USGS) and the Pacific Northwest Seismic Network (PNSN) through the volunteer-powered NetQuakes program. USGS initiated the program in California in 2009 as a cost-effective means of expanding its seismic data collection capability, and in early 2010, PNSN began installing NetQuakes instruments in and around Seattle to help the area better prepare for future large earthquakes.
Driven by a desire to help these preparations along, to be part of a group effort, and by an abiding (though not necessarily professional) interest in science and technology, the members of this unusual family are part of a growing movement in earthquake research and monitoring that is making use of the explicit support of citizen scientists.
At present, 90 NetQuakes seismometers populate PNSN’s network. They are scattered around Puget Sound from Olympia to the northern border town of Blaine, with the greatest concentrations located along Seattle’s waterfront and on the city’s north side. Single stations are located to the east as far as Yakima and to the west on the Pacific coast at Ocean Shores, and 15 sites were also recently added in and around Portland, Ore. With a few exceptions, all are hosted by volunteers — private individuals mostly and a few small businesses — who agreed to give up several square feet of space in a garage, basement or office so that the unassuming blue “box” could be secured into place.
With a simple design and a price tag of about $4,500 apiece, NetQuakes boxes are relatively inexpensive for USGS to purchase and maintain compared to the more sophisticated instruments that seismologists typically deploy, which cost between $10,000 and $30,000. All told, more than 350 of the boxes are up and running in the U.S., with a few more sprinkled around the planet in places like Haiti and Nepal. The number is a far cry from the thousands that were initially envisioned, but given limited funding and staff available to install them, the volunteer response — roughly 6,150 applications total, with about 2,000 in the Northwest alone — has been overwhelming, says Jim Luetgert, a NetQuakes organizer and geophysicist with USGS in Menlo Park, Calif.
The NetQuakes Family
Hayes’ involvement is characteristic. An 18-year resident of the area who runs a local Internet provider and who grew up in a “sciency house,” she counts emergency management types among her clients and is familiar with the seismic threat to the region. During the 2001 magnitude-6.8 Nisqually temblor — the last sizeable earthquake to hit Puget Sound — surface waves rippled through the streets and shook her car as she drove through Olympia.
In March 2011, she watched on television as Japanese towns were swallowed by waves of black, debris-filled water in the wake of the massive quake that struck off the country’s coast — an area that, from a tectonic standpoint, is eerily similar to the Pacific Northwest. If that’s what happened there, in industrialized, hyper-organized Japan, she wondered, how would this area fare given similar circumstances?
So, was it recollections of the modest Nisqually quake, which “tore up downtown [Olympia],” or the eventuality of another big one in the Northwest that spurred her to action when PNSN asked for applications to host the new cluster of seismometers?
“No. It’s just cool,” she laughs. “Who has one except for me? The coolest kid on the block.”
Inside the box is an accelerometer, like those in modern laptops, that continuously monitors 3-D ground movement. When shaking exceeds a certain threshold — depending on its proximity, a magnitude-3.0 to -5.0 earthquake will typically do the trick — data are recorded and quickly sent to USGS servers. Within minutes, uploaded data in the form of seismograms are posted online for the public to view.
Other than the minimal floor space, participation requires only a suitable location, a high-speed Internet connection, a modicum of electricity — about 25 cents per month under normal conditions — and a willingness to change the batteries occasionally. (For more significant repairs, instruments are typically swapped out by mail at USGS’ expense — not unlike Netflix, the by-mail movie rental company that inspired the NetQuakes name.)
Unfortunately for their hosts, the seismometers are not especially interactive. Boxy and bolted down, there are few signs of life except for the occasional blinking of multicolored LEDs to signal that the instrument is recording data or communicating with home base. Days can pass without an event to trigger a response. And yet, the instruments’ immobility does not dampen the interest of many NetQuakes volunteers.
“Being part of a larger experiment seemed cool,” says Michael Andersson, a physics lab manager at the University of Washington, “and I get to brag to my friends.” After his box — among the first to be deployed in the area — was installed at his home on Seattle’s north side, he couldn’t stop checking online to see if it had transmitted data. It was “like a new cell phone,” he says. And the novelty hasn’t worn off: “If there is any little earthquake around, I’ll say to friends around the world, ‘Hey, check this out, there was this little earthquake 200 hundred miles off our coast, and here’s what showed up at our house.’”
Online seismograms provide a component of public outreach, but the NetQuakes data are primarily intended to be of scientific use, Luetgert says. For earthquakes larger than about magnitude-5.0, NetQuakes data can be used to more accurately determine the magnitude, epicentral location and fault displacement. This sets the program apart from other crowd-sourcing earthquake efforts, he says, which are useful for providing early warnings of where and when shaking and damage occur, but are limited by the lower quality of data produced and the inconsistency of measurement locations.
First deployed in Northern California, the seismometers were initially intended to help seismologists gauge localized ground shaking, which can vary greatly over kilometer-scale distances, and damage patterns during the next big rupture on the Hayward Fault that runs beneath Oakland, Luetgert says. The Hayward last ruptured in 1868 with destructive results. With a recurrence interval of about 140 years for large earthquakes on the fault and a population of more than 7 million in the San Francisco Bay Area, a lot is at stake.
After its inception, NetQuakes was quickly expanded to other at-risk areas up and down the West Coast. Southern California is now relatively well instrumented with NetQuakes boxes, as is the Northwest.
For decades, seismologists have been uncovering paleoseismic evidence of numerous major earthquakes that have occurred on the Cascadia subduction zone, most recently in 1700. Sunken “ghost” forests and anomalous inland sand deposits indicate the sudden topographic collapse that accompanied the quakes and drastically altered the landscape. Recurrence intervals among the largest of these events hint at something big in the offing.
Whether it will happen in two years, 200 years or even further down the road is unknown, but damage scenarios for either a subduction-related megathrust earthquake or a significant rupture on one of the many faults that traverse the shallow subsurface are worrisome. Given the present state of the area’s infrastructure, the expected shaking and the area over which it would be felt, it shouldn’t be surprising that “the most complex, costly, dangerous [hazard] that’s going to happen here is a really big earthquake,” says Barb Graff, director of the Seattle Office of Emergency Management.
When the Northwest’s next big one does come, USGS and PNSN scientists intend to document its effects on the area’s urban landscape thoroughly. This is where the area’s NetQuakes instruments come in. Seismologists have been able to produce good city-specific maps of ground shaking using data from pre-existing seismic networks, says Doug Gibbons, a research assistant at the University of Washington and a NetQuakes technician. But the seismometers in these networks are far less densely spaced, located predominantly in out-of-the-way areas, and far more expensive compared to NetQuakes boxes. With NetQuakes, which is intended to provide dense coverage in urban settings, “hopefully we can even go to neighborhood-specific shaking,” he says.
Along with earthquake strength and proximity, ground shaking is considerably affected by soil compaction. This is of special concern around Puget Sound, where much of the anthropogenic landscape is built on relatively loose glacial till and sediment that amplify ground motion. “Earthquake shaking … has a tendency to disproportionately pick on the vulnerable,” which includes not only people, but also unreinforced masonry buildings (more than 800 in Seattle alone), and transportation routes, Graff says. Low-lying areas near water, which abound in the Pacific Northwest and the San Francisco Bay Area, are particularly susceptible to liquefaction — when compacted soil is jostled into a water-saturated slurry, losing its mechanical strength in the process.
Gauging ground shaking is just one of three main functions of NetQuakes, says Steve Malone, a former PNSN director who hosts a box at his home. The data should also be useful as a “triage implement” during or immediately after an earthquake to guide emergency responders and building inspectors to areas that may have been damaged. In particular, some buildings might suffer damage that is subtle — micro-cracking, for example — or that is not readily apparent from the outside. Using indications from NetQuakes about the magnitude, frequency and duration of shaking, he says, engineers could identify a building that “is starting to get close to its design limits,” and decide that “we better go inspect it even if we don’t see anything at first.” And going forward, Malone says, the data will aid in improving building design and construction to minimize future vulnerabilities.
NetQuakes’ Value in the Community
An important byproduct of NetQuakes’ solicitation of citizen volunteers, Luetgert says, is that it raises public awareness of seismic threats. “If you can go out to your garage and trip over this little box every morning, it reminds you that ‘Oh yeah, we do have to worry about earthquakes around here.’” It also increases the visibility of USGS’ and PNSN’s outreach efforts.
But the program’s biggest value lies in “making the community realize that emergency preparedness, response and recovery is a team sport, and [citizens] have a role to play in it,” Graff says. The concern is that “there is a growing public expectation that government … agencies will just take care of everything,” but, she says, self-sufficiency is key for coping with a future disaster. In her view, NetQuakes supplements existing municipal programs that encourage individuals and families to safeguard their homes and neighborhoods to coordinate future response efforts on a local scale.
The message of self-sufficiency and team spirit has resonated with some NetQuakes volunteers. Mike Seeger’s home is protected by a sturdy foundation and earthquake insurance. And sitting next to bundles of flattened boxes and spools of decorative ribbon on the floor at the back of his floral shop in Fife, about 45 kilometers south of downtown Seattle, he also has a blinking blue NetQuakes box. “My business relies on the community — all the churches, the schools, the people who live here,” Seeger, a retired Army helicopter pilot who counts participation in NetQuakes among his many civic-minded activities, says of his motivations.
Growing the Network
Since NetQuakes began operating in 2009, many small earthquakes have been successfully recorded and reported from volunteers’ homes and businesses. But as Malone and others note, the program’s “true value” will be tested when the next large earthquake occurs and strong shaking triggers responses from many of the instruments. This is when seismologists and engineers should be able to begin teasing apart localized differences in shaking and damage and to relate the differences to nearby geology and construction practices.
In the meantime, organizers hope to continue installing as many additional blue boxes as their funding will allow. The program has already expanded to Alaska, Hawaii, Oklahoma, Utah and elsewhere, even including a few East Coast cities like New York and Boston. The main target areas for ongoing deployment, however, continue to be the population centers of California and the Pacific Northwest, where the threat from earthquake damage is most prevalent.
For PNSN scientists, choosing where to place new NetQuakes boxes is a matter of matching holes in current coverage with available volunteers. Malone says there are parts of the northern Puget Sound area and northern Oregon, for example, that are underrepresented. In some areas, volunteers have been scarce. And finding locations that meet site requirements — one- or two-story buildings that have a concrete slab foundation to which the box can be bolted — is often easier said than done.
Despite the difficulty of picking out a few optimum sites from the many applications they have received, NetQuakes organizers are always looking for new volunteers. They occasionally issue press releases to drum up interest, and they tout the perks of participation — mostly intangible — whenever they can.
One such perk for hosts is the option to imbue their box with a little personality using the last three letters of its four-letter designation. (Each box in the PNSN cluster begins with “Q.”) While most stations simply reflect the name of the host, or a nearby town or street, others are a bit more creative. There is QHOP, named by a part-time home brewer; QGFY is an homage to one host’s favorite Disney character; and then there is QUIN, Lisa Hayes’ “adopted son.”
Hayes says she and her husband wonder “if any of the parents of these boxes are as proud as we are.” She doubts it. They posted pictures of QUIN on Facebook after it was installed, they check in online to see what it’s been up to when they’re out of town, and, like Andersson, they “totally” brag about it to friends.
From his observations, Gibbons, who has installed many of PNSN’s instruments, suggests that the boxes are indeed a point of pride for many. For others who do not regularly pay attention to them, hosting one is sometimes more a matter of fulfilling a “civic duty.” For Hayes, it appears the two are not mutually exclusive, although she doesn’t acknowledge it right away.
“I hate to tell you [but] I didn’t do it for you guys; it wasn’t my civic duty. It was just so I could call my dad and be like, ‘Guess what?’” she jokes, referring to her professor father. Coming back to the topic minutes later, though, she adds that “the monitoring that we’re doing now … is something that we can contribute that’s very valuable because, should the ‘big one’ happen, it would probably be the first time, at least regionally, we would have the data to look back at to see exactly what happened.”