"The Big One," on the Horizon
February 1, 2024 | View PDF
In the Pacific Northwest, there are two types of natural disasters you probably think about fairly often because of either secondhand or lived experience: earthquakes and volcanoes.
Unlike other seismically-active parts of the world, the PNW hasn’t had a devastating earthquake in recent history, but it is expected to. A magnitude 9.0 earthquake is due to hit the Cascadia subduction zone, a fault line stretching from Vancouver Island to Northern California, within the next 50 years.
This earthquake would trigger a tsunami that would wipe out many of the rural communities on the Oregon and Washington coast. A 2015 New Yorker article widely publicized this fact, along with a portentous quote from an employee at the Federal Emergency Management Agency’s Northwest division: “Our operating assumption is that everything west of Interstate 5 will be toast.”
As an Oregon resident just barely east of Interstate 5, I think about the Cascadia subduction zone a lot, as evidenced by my choice to begin this newsletter with it.
But this earthquake – ominously coined “The Big One” – is not the protagonist (or rather, antagonist) of this week’s newsletter. No, I’m interested in another seismically-related phenomenon: volcanoes. One volcano, in particular.
Hellfire and Brimstone
While PNW residents may not remember any major earthquakes, the date May 18, 1980 probably strikes a chord for anyone who was alive and present in the region at the time.
At 8:32am on a Sunday, a magnitude 5.1 earthquake hit southwestern Washington and triggered a landslide on Mount St. Helens, a 9,677 foot volcano that had been showing signs of eruption for months. The landslide – the largest one ever recorded in human history, according to the U.S. Geological Survey – took out both the summit and the cryptodome, a huge bulge on the northern side of the volcano that had formed as magma pushed out from within.
In just a few moments, Mount St. Helens lost almost 1,000 feet of elevation and would lose several hundred more before the day’s end as tephra (rock fragments from the volcano’s interior) were blasted into the air. Once a symmetrical, cone-shaped mountain, the eruption carved out the entire north side, leaving a massive crater in its wake.
The Mount St. Helens eruption on May 18, 1980. (Photo courtesy of the U.S. Geological Survey)
Among the many obvious differences between a volcano and an earthquake, one in particular stands out: volcano eruptions are a helluva lot easier to predict than an earthquake. Of course, it’s impossible to predict the exact moment of eruption or its severity, but a volcano’s got some telltale signs it’s about to burst. There are earthquakes, steam, ground swelling, new hot spots, and changes in gas composition.
An earthquake, on the other hand, provides very little for scientists to go off of. The best information comes from looking back in time at an area’s seismic history. Scientists can calculate the probability of a significant earthquake occurring within a certain time period, but never exactly when.
Unlike earthquakes, people knew that Mount St. Helens would erupt months before it actually did. A danger zone was mapped out by government officials to show where people should not be when it erupted, and the people living within this zone were told to evacuate prior to the eruption.
Yet 57 people were killed on May 18, 1980, and only three of them were in the designated danger zone, according to Steve Olsen, author of “Eruption: The Untold Story of Mount St. Helens.” The rest were in areas labeled safe.
Money Over Lives
The designated danger zone ended where logging by the timber company Weyerhaeuser began. Local officials were reluctant to label logging areas as dangerous because it would stop business. In a National Geographic interview with Olsen, he’s quoted saying “if [the eruption] had happened during a weekday, hundreds of loggers would have died. I talked to people who said, ‘If it had been Monday through Friday during the day, I wouldn’t be here talking with you right now.’”
The fatality number from the Mount St. Helens eruption is an example of mismatched priorities – money over human life. But it’s also an example of how little we really do know about the random, destructive forces that lie beneath our feet. Yes, volcanoes are easier to predict than earthquakes; no, that should not give you peace of mind.
The Powerful Pull of Home
A few people chose to stay home, inside the danger zone, during the Mount St. Helens eruption. The person made most famous by this decision was Harry Truman (not the president), the eccentric 83-year-old owner of Mount St. Helens Lodge along Spirit Lake at the base of the mountain. In response to evacuation efforts, he was quoted saying “they’ll never get me off this mountain. Spirit Lake and Mount St. Helens are a part of me – they’re mine. They’re as much a part of me as my arms and legs.
Truman was more stubborn than a lot of people would be in his situation, but I understand his thinking. Home is people and place; the older you get, the more rooted to place you can become. These strong ties aren’t exclusive to rural places – I have ties to several cities – but it’s no coincidence that people tend to “go home,” to settle in smaller communities, as they age. Harry Truman told journalists that “life comes in three parts.”
“First,” he said, “you work your ass off and get a few coupons to clip. Then you hang around the crest for a while. Then it’s all downhill and clipping coupons if you’re lucky – just riding her out. That’s where I am now, kind of coming down the hill.”
It becomes harder to leave a place the longer you’re there, no matter the storms that may be headed your way.
The next PNW catastrophe probably won’t be a volcano (knock on wood). But there is significant likelihood the Big One – that 9.0 earthquake – will hit within some of our lifetimes.
Yet even with this knowledge, there are a whole lot of people remaining west of Interstate 5, inside the tsunami danger zone along the rural Oregon and Washington coast. Of the factors inside and outside our control that dictate where we live, I do find it admirable when people choose to stay.
Whether it’s a rural-specific characteristic or not, it is certainly one that presents itself strongly in rural communities across the country, and it’s my favorite small town trait: the determination, against all odds, to hold onto home.