Seismologists are saying that Washington, Oregon and California are overdue for “the Big One.” They are referring to a major earthquake that will devastate the now densely populated coastal areas of the U.S. West Coast.
The length of time roughly corresponds to an earthquake’s magnitude. A quake of fifteen seconds is in the high sixes, thirty-seconds, in the mid-sevens. One minute goes to the high sevens. Two minutes enters the eights. A three-minute quake hits the high eights, while four minutes, hits 9.0.
Way back in 2005, Yasutaka Ikeda, a Japanese geologist, predicted that Japan would soon have a 9.0 magnitude or higher with catastrophic consequences. He was largely ignored. But in 2011, a 9.0 quake devastated northern Japan and with its subsequent tsunami killed over 18,000 people.
Scientists are saying that the U.S. West Coast is due for a massive quake. They say the maximum capability of the San Andreas Fault is only 8.2, which is a powerful earthquake, but only 6% of the Japanese event.
The Cascadia subduction zone just north of the San Andreas Fault line, however, runs for 700 miles off the coast of the Pacific Northwest. The Juan de Fuca tectonic plate is slipping steadily beneath North America. But North America is stuck against the surface of the plate, it is pushing North America upward and compressing eastward at a rate of four to forty millimeters a year. Sooner or later, according to seismologists, North America will rebound like a spring. When it does, a very big earthquake is likely, dropping the continental shelf west of the Cascade mountains by as much as six feet and rebound to the west 30 to 100 feet. Some of that shift will be under the ocean forcing a colossal quantity of water to surge upward sending giant waves to Japan and to the United States.
“By the time the shaking has ceased and the tsunami has receded, the region will be unrecognizable,” Kenneth Murphy, FEMA director for the region says. “Our operating assumption is that everything west of Interstate 5 will be toast.” That’s 140 thousand square miles, including Seattle, Tacoma, Portland, Eugene, Salem, Olympia, and seven million people. When it happens, it will be the worst natural disaster in American history.
FEMA projects a minimum of 13,000 deaths and 27,000 injuries in a major Cascadia event. “This is one time that I’m hoping all the science is wrong, and it won’t happen for another thousand years,” Murphy says. The odds of a big earthquake in the next fifty years are approximately three to one.
The problem is that the Pacific Northwest is unprepared for it. The Juan de Fuca is part of the “ring of fire,” a volcanically and seismically volatile region that runs from New Zealand through Indonesia and Japan, across to Alaska, and down the West Coast of the Americas to Chile. Most earthquakes in the region are a result of continental plates getting unstuck from oceanic plates.
The Cascadia subduction zone has “all the right anatomical parts,” yet never in recorded history has it caused a major earthquake. However, by studying the rings of dead cedar trees near the Washington coast, scientists realized in the 1980s that there was an earthquake all the way back in 1699. Earthquake and tsunami records in Japan go all the way back to 599 A.D. A Japanese scientist matched the 1699 earthquake to a corresponding “orphan” tsunami 600 miles long that hit Japan at the same time.
Native American history also brings out evidence of salt-water floods and sinking land, pointing to the same time period around 1700. Scientists have also been studying the seafloor, which gives the history of the subduction zone through deposits that fell there as they fell off of the continental plate during earthquakes. Scientists have been able to determine how much of the zone has ruptured, how often, and how drastically. Scientists now think that on average, every 243 years, an earthquake happens in Cascadia. Doing the math, the U.S. Pacific Northwest is now 315 years into a 243-year cycle.
Early warning systems now available aren’t used in the region. The vast majority of buildings were not built to today’s seismic standards. FEMA estimates more than a million structures will collapse; schools, hospitals, office buildings and bridges. Most of Seattle is built on liquefiable land.
“The sloshing, sliding, and shaking of a major quake will trigger fires, flooding, pipe failures, dam breaches, and hazardous-material spills.” In “four to six minutes the shaking will subside. For another few minutes, the region, upended, will continue to fall apart on its own. Then the wave will arrive, and the real destruction will begin.”
Thousands will die in the inundation zone. “We can’t save them,” says Kevin Cupples, city planner for Seaside, Oregon. “I’m not going to sugarcoat it and say, ‘Oh, yeah, we’ll go around and check on the elderly.’ No. We won’t.” Nor will anyone save the tourists. The tsunami will not rise up from the surface of the sea and break from above. It will look like the whole ocean, elevated, overtaking the land. The inundation zone will be scoured of structures from California to Canada, making the tsunami inundation zone uninhabitable for years.
Eighty miles off the coast of Washington State, ten thousand feet below the surface of the sea, the geological clock is ticking.
“While appearing to the children of men as a great physician who can heal all their maladies, he will bring disease and disaster, until populous cities are reduced to ruin and desolation. Even now he is at work. In accidents and calamities by sea and by land, in great conflagrations, in fierce tornadoes and terrific hailstorms, in tempests, floods, cyclones, tidal waves, and earthquakes, in every place and in a thousand forms, Satan is exercising his power. He sweeps away the ripening harvest, and famine and distress follow. He imparts to the air a deadly taint, and thousands perish by the pestilence. These visitations are to become more and more frequent and disastrous. Destruction will be upon both man and beast.” The Great Controversy, page 589-590
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