Read Later Remnants of a 2,000-year-old spruce forest on Neskowin Beach, Oregon — one of dozens of “ghost forests” along the Oregon and Washington coast. When the next full-margin rupture happens, that region will suffer the worst natural disaster in the history of North America, outside of the 2010 Haiti earthquake, which killed upward of a hundred thousand people. Under pressure from Juan de Fuca, the stuck edge of North America is bulging upward and compressing eastward, at the rate of, respectively, three to four millimetres and thirty to forty millimetres a year. Even those numbers do not fully reflect the danger—or, more to the point, how unprepared the Pacific Northwest is to face it. That time line does not allow for finding a flashlight, tending to an earthquake injury, hesitating amid the ruins of a home, searching for loved ones, or being a Good Samaritan. The building itself was base-isolated, a seismic-safety technology in which the body of a structure rests on movable bearings rather than directly on its foundation. The cedars are spread out across a low salt marsh on a wide northern bend in the river, long dead but still standing. Almost all of the world’s most powerful earthquakes occur in the Ring of Fire, the volcanically and seismically volatile swath of the Pacific that runs from New Zealand up through Indonesia and Japan, across the ocean to Alaska, and down the west coast of the Americas to Chile. Tectonic plates are those slabs of mantle and crust that, in their epochs-long drift, rearrange the earth’s continents and oceans.
A grown man is knocked over by ankle-deep water moving at 6.7 miles an hour. That time frame predated by more than a hundred years the written history of the Pacific Northwest—and so, by rights, the detective story should have ended there.But it did not. That is no longer a problem of information; we now understand very well what the Cascadia fault line will someday do. He thought better of it, and lurched away. The accuracy of these distances are limited both because of earthquake location uncertainties (typically for PNSN earthquakes, less than 1 km.) Yamaguchi took samples of the cedars and found that they had died simultaneously: in tree after tree, the final rings dated to the summer of 1699. The shaking intensified. It will be a five-story deluge of pickup trucks and doorframes and cinder blocks and fishing boats and utility poles and everything else that once constituted the coastal towns of the Pacific Northwest.To see the full scale of the devastation when that tsunami recedes, you would need to be in the international space station. Depending on location, they will have between ten and thirty minutes to get out. Twenty-two per cent of Oregon’s coastal population is sixty-five or older. (Rocks, like us, get stiffer as they age.) Geophysics. At its tallest, it is forty-five feet high—lower than the expected wave in a full-margin earthquake.
If you travel five thousand miles due west from the ghost forest, you reach the northeast coast of Japan. That is what the Juan de Fuca plate is doing: slipping steadily beneath North America. “Let’s just say I would rather not be here.”The first sign that the Cascadia earthquake has begun will be a compressional wave, radiating outward from the fault line.
But, covertly, they also present us with problems of time. For want of a nail, the war was lost; for fifteen independently insignificant errors, the jetliner was lost. The next big earthquake is due in the Pacific Northwest—but now scientists have pinpointed where along the coast a large earthquake is most likely to happen, according to a study published Monday. At present, all Dougherty can do is make sure that his students know how to evacuate.Some of them, however, will not be able to do so. The earth snapped and popped and rippled. Each sample contains the history, written in seafloorese, of the past ten thousand years. But, lulled into nonchalance by their seemingly benign environment, most people in the Pacific Northwest have not done so. Washington State Park properties within the inundation zone see an average of seventeen thousand and twenty-nine guests a day. In theory, those who are at home when it hits should be safest; it is easy and relatively inexpensive to seismically safeguard a private dwelling. If, on that occasion, only the southern part of the Cascadia subduction zone gives way—your first two fingers, say—the magnitude of the resulting quake will be somewhere between 8.0 and 8.6. Hotels and businesses are not required to post evacuation routes or to provide employees with evacuation training. By four minutes, an earthquake has hit magnitude 9.0.When Goldfinger looked at his watch, it was quarter to three.
“When that tsunami is coming, you run,” Jay Wilson, the chair of the Oregon Seismic Safety Policy Advisory Commission (The time to save people from a tsunami is before it happens, but the region has not yet taken serious steps toward doing so.
Canada was not yet a country. The question facing geologists in the nineteen-seventies was whether the Cascadia subduction zone had ever broken its eerie silence.In the late nineteen-eighties, Brian Atwater, a geologist with the United States Geological Survey, and a graduate student named David Yamaguchi found the answer, and another major clue in the Cascadia puzzle.