The Really, Really Big One… Again

 

The Really, Really Big One… Again

Somewhere around 1700, a “ghost” tsunami of massive proportions slammed into Japan, wreaking havoc – death and disaster – that no one truly understood. Centuries later, bio-historians and earthquake scientists discovered the buried remnants of the entire forests in various areas in our Pacific Northwest… from that quake estimated at 9.2 on the Reichter Scale that traced back to 1700. Those American researchers came to the conclusion that his quake and the resultant tsunami killed every living thing in that American land, from today’s Alaska to northern California, centered around Oregon. Plants, animals and people all perished. Further research showed that this was a recurring tectonic plate release that occurred roughly every 400 years. Hmmm! That means that we are living in a period of expected recurrence. That “ghost” tsunami was finally explained.

If you’ve ever driven up PCH 1 from north of San Francisco, through Oregon, past Seattle… into British Columbia… you may recall the litany of “tsunami zone” signs along the way. Also, if you think of the Columbia River, separating Oregon from Washington, you might not guess that this beautiful river also became a tsunami superhighway that carried that wall of water deep inland where that 1700 watery wrecking ball did even more damage. Until recently, Oregon did not permit major buildings in tsunami zones for obvious reasons. But for whatever reasons, mostly relying on significant upgrades in engineering techniques, Oregon recently relented to permit such reinforced construction… even for a public high school. Add the 400-year cycle expectancy to 1700, and guess comes up: 2100. And it’s 2026, which makes 60–100-foot waves in the modern Pacific Northwest seem pretty terrifying. These are only estimates, and they could be wrong. Then again…

Cassian Holt, writing for the January 12th morningoverview.com, tells us that scientists are quite concerned: “The Cascadia Subduction Zone is a 600 mile long boundary where an oceanic plate dives beneath North America, quietly building strain that can release in a single, continent scale jolt. State emergency planners in Oregon describe it as one of the most dangerous seismic threats in the country, because it sits just offshore of dense population centers yet produces few small quakes to remind people it exists. Historical and geological evidence show that this fault has produced repeated giant earthquakes, and current assessments say Oregon has the potential for a 9.0+ magnitude earthquake driven by this buried plate interface.

“Those projections are not abstract. A detailed hazard profile notes that Oregon has the for a 9.0+ event that would send a wall of water racing toward the coast within minutes, leaving little time for evacuation. Native American accounts of shaking and flooding, preserved in stories along the coast, line up with offshore sediment records that point to a massive Cascadia rupture in the early 1700s. When I look at that convergence of science and tradition, it underlines that the region has already endured one full scale megathrust and is likely to face another…

“In the worst case, a 9.2 megathrust would combine intense shaking with a tsunami that strikes the Pacific Northwest coastline in less than half an hour, overwhelming low lying towns and ports. Video explainers on The Cascadia scenario describe how a 9.2 quake and tsunami could devastate the Pacific Northwest, flattening buildings, shredding roads and isolating coastal communities that depend on a handful of bridges and highways. Emergency managers warn that critical lifelines like fuel pipelines, fiber optic cables and interstate rail lines would be severed in multiple places at once.

“Scientists now frame a 9.2 m Cascadia rupture as a candidate for the largest natural disaster in U.S. history, with cascading impacts on housing, trade, and energy that would ripple far beyond the immediate impact zone. In one widely shared briefing, Scientists warn that the Cascadia Subduct interface is capable of a 9.2 m event that would hit the Pacific Northwest with shaking that lasts several minutes, long enough to collapse unreinforced masonry, damage modern high rises and trigger landslides across mountain valleys. When I weigh those projections against the region’s aging infrastructure, it is hard to avoid the conclusion that recovery would take years, not months.

“One of the most unsettling findings in recent research is that the main danger is not only the tsunami, but the way the land itself could drop. Analysts examining Cascadia’s Hidden Risk describe how one earthquake could sink the U.S. Pacific Coastline Beneath Six Feet of Water, not because the ocean suddenly rises, but because the land falls. Beneath the coastal plain, the locked fault would snap, causing broad subsidence that leaves neighborhoods, ports and wetlands at a permanently lower elevation relative to sea level.” In short, this quake would be a trigger for several additional devastating events, with some land collapsing, water rerouting, forests and building gone… and not all happening in the immediate expected sequence.

I’m Peter Dekom, and even with millions of Americans killed, buildings leveled, commerce decimated, if this tragedy were to occur during the Trump administration, there are two additional risk factors that have to be added to the equation: FEMA is being cut back significantly… and these coastal regions (at least in the US) mostly vote Democratic.