Just off the Pacific Northwest coast there's a sleeping giant, the Cascadia subduction zone, a fault line capable of massive—magnitude 9.0 or greater—earthquakes. Geologists warn the fault could slip at any moment. Yet towns and cities from Northern California to Vancouver Island remain woefully unprepared for what follows: the catastrophic destruction of infrastructure, an economic tailspin, and the death of thousands.
AAAS Fellow Roberts Yeats is one scientist sounding the alarm: "If we have a Cascadia subduction zone earthquake, it's going to devastate Oregon and Washington. It will take us decades to recover," says Yeats.
Yeats is professor emeritus of geology at Oregon State University. Still actively publishing at 83, he continues to live in Oregon, right in the heart of Cascadia country, where for the past 30 years he's campaigned to embed the fault's dangers in the hearts and minds of his Northwest neighbors.
On his educational mission, Yeats has gathered geologists, written books and op-eds, and reached out to the press. His philosophy is simple: "We can do the science, but if people aren't going to pay attention to the implications, what's the point?"
The Cascadia subduction zone works something like this: Below the waters off the Pacific Northwest coast, the Juan de Fuca plate is slowly being forced under the North American plate. This "subduction" builds up strain that's eventually released in monster earthquakes similar to what rocked Japan in 2011.
Historically, quakes also have been known to erupt from the fault's southern half near northern California and southern Oregon. This typically produces magnitude 8.0 shakers. The seismic evidence comes largely from mud cores sampled along the Northwest coast. The cores—analyzed by Chris Goldfinger, a student of Yeats—show signs of earthquake-induced, underwater landslides. Both types of quakes can create killer tsunamis, and both are likely in the next 50 years.
But in the early 1980s, shortly after Yeats settled in Oregon, this wasn't yet known. In fact, geologists couldn't agree if Cascadia was active or not. The problem was, while the fault was a known subduction zone, it didn't have the recorded activity that was common among other subduction zones. This led many to conjecture that the fault was unlikely to erupt.
That changed in 1983 when geologist John Adams, while combing through National Geodetic Survey data, discovered evidence for continental uplift. Upon first hearing Adams' argument, Yeats admits he told him not to publish, fearing the sour news might needlessly alarm the public. He now regrets this. More earth-shaking evidence followed, when researchers found hints in sediment layers in a Washington estuary that indicated that past Cascadia-triggered tsunamis had deluged local coastlines.
In early 1987, concerned the evidence for an active subduction zone had reached a critical juncture, Yeats brought together the world's leading Cascadia researchers to hash out the science. To his surprise, after comparing notes, the geologists reached a consensus: The Cascadia subduction zone was active and dangerous. Yeats describes this as a "paradigm shift," one he thought the public had a right to know about.
Yeats became a regular expert for journalists reporting on Cascadia, but soon realized that his message wasn't sticking. There seemed to be a severe case of Cascadia amnesia, he said. Worse still, reporters had started calling him "Dr. Doom." So Yeats started doing his own reporting. It started with op-eds in local papers. Then, in 1998, he wrote, "Living with Earthquakes in the Pacific Northwest," the first book on the Cascadia subduction zone intended for a general audience.
Yeats' current writing project, tentatively titled, "Earthquake Time Bombs," also written for a general readership, details the world's active faults and the communities affected by them. A previous book of Yeats', "Active Faults of the World," published by Cambridge University Press, covers the same topic but was written for a scientific audience.
Both books originate from work Yeats performed with his seismic consulting firm, Earth Consultants International. He created the firm with colleagues shortly after he retired from teaching in 1997. The firm assesses seismic threats the world over. Yeats says his most memorable work was in Afghanistan, where, in 2002, he helped a small town rebuild after a quake.
"The people, I just fell in love with the people," he says.
However, Yeats hasn't forgotten about the danger on his doorstep. He continues to write op-eds, recently lending his voice to Portland parents seeking funds to retrofit the city's seismically vulnerable schools. His new book also includes a chapter on Cascadia. Here Yeats takes a turn from scientist to gumshoe reporter. He plans to write about how many landlords have long-eluded requirements to seismically retrofit their older buildings.
Yeats hopes Cascadia's danger will register before it's too late.
"If the earthquake happens before we make our case," says Yeats, "this will be the biggest failure of my career."