Skip to main content

Geo Bits: Cascadia Edition

Fear and fascination haunts the Cascadia subduction zone in this collection of recent articles

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


The Cascadia subduction zone is endlessly fascinating to many people; endlessly terrifying to others (waves, points to self). So I've been collecting a heaping helping of links for ye.

Now may be a really good time to remind y'all about earthquake safety. Even if you don't live anywhere near Cascadia, have a look: you never know when the earth might get shaky where you live, work, or play.

The Seattle Times: Seattle, suburbs would lose all water pressure within 24 hours of catastrophic earthquake, city study says


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


[A] new study says Seattle would lose all water pressure within 24 hours of a catastrophic quake and would need at least two months to entirely restore water service in the city. Suburbs served by Seattle Public Utilities (SPU), which commissioned the study, would also lose service – including Bothell, Woodinville, Kirkland, Redmond and Bellevue.

With Seattle facing 15 to 20 percent odds of a severe earthquake in the next 50 years, the study says the city should spend $850 million through 2075 to mitigate water-system risks posed by the “Big One,” playing catch-up to California cities that already have taken dramatic steps.

Gizmodo: Inside the Plan to Prepare the Pacific Northwest for a Catastrophic Earthquake

In the year 1700, an earthquake rocked the Pacific Northwest, sending tsunami waves not just toward the local coastline but all the way across the ocean to Japan. Inspiring legends at the time, scientists now know that the quake was triggered by a catastrophic jolt on the Cascadia Subduction Zone, where the Juan de Fuca tectonic plate meets and descends beneath the North American plate.

There hasn’t been a so-called megathrust earthquake in the region since, but as stress on the boundary continues to build, another in the future is inevitable. Geoscientists have long called for an early warning system to prepare for such an eventuality, which could easily become among the worst disasters in U.S. history, killing tens of thousands and displacing many more, while inflicting tens of billions of dollars of damage. Now, Congress is finally starting to listen.

A new bill—HR 876, the Pacific Northwest Earthquake Preparedness Act of 2019—is the latest sign that the idea of an early warning system for the Pacific Northwest’s version of the “Big One” is gaining traction.

Phys.Org: Hundreds of bubble streams link biology, seismology off Washington's coast

Off the coast of Washington, columns of bubbles rise from the seafloor, as if evidence of a sleeping dragon lying below. But these bubbles are methane that is squeezed out of sediment and rises up through the water. The locations where they emerge provide important clues to what will happen during a major offshore earthquake.

City Journal: Off the Richter Scale: Can the Pacific Northwest prepare for the cataclysmic quake that’s coming?

Americans have long dreaded the “Big One,” a magnitude 8.0 earthquake along California’s San Andreas Fault that could one day kill thousands of people and cause billions of dollars in damage. The Big One, though, is a mere mini-me compared with the cataclysm forming beneath the Pacific Northwest.

Roughly 100 miles off the West Coast, running from Mendocino, California, to Canada’s Vancouver Island, lurks the Cascadia Subduction Zone, where the Juan de Fuca Plate is sliding beneath the North American Plate, creating the conditions for a megathrust quake 30 times stronger than the worst-case scenario along the notorious San Andreas, and 1,000 times stronger than the earthquake that killed 100,000 Haitians in 2010. Shockwaves will unleash more destructive force against the United States and Canada than anything short of nuclear war, a giant asteroid strike, or a civilization-threatening super-volcano.

We didn’t even know a megaquake was coming until recently.

Rosetta Stones: Oregon Is About to Get a Lot More Hazardous

When you live in an area at as much geologic risk as Oregon, you would expect that government officials would maybe, possibly, take those risks seriously. But the people who currently govern Oregon seem quite determined to ignore hazards and let the state languish unprepared.

Rosetta Stones: Thunderbird and the Orphan Tsunami: Cascadia 1700

By most accounts, it was a dark and stormy night when Thunderbird and Whale fought their cataclysmic battle. Darkness comes early in the Pacific Northwest in January: the sun had been down for hours, and in the dark and cold, no one could see Thunderbird swoop down. But they felt it when she grabbed Whale in her talons, and rose up with it. Then she dropped Whale from a great height, slamming it into the ground. The land shook, and the waters receded. Some people knew to get into their canoes. Some didn't have time. And then came the great flood, which destroyed whole villages, and left many canoes stranded in the trees.

That's one version of what happened that night.

.... Enjoy?