Twenty years ago this Sunday, at 10:54 a.m., the magnitude 6.8 Nisqually earthquake suddenly upended lives across the Puget Sound region. Hundreds were injured and property loss totaled in the billions of dollars. Much of the damage happened in places closest to the epicenter, like Olympia, but destruction also happened surprisingly far away, especially in the brick and stone buildings, bridges and viaducts of historic Seattle. Many of the damaged structures were built upon the Seattle Basin and soft sediments of the Duwamish River in the SoDo neighborhood, which amplified the shaking and even liquefied during the earthquake.
For the past two decades, all has been pretty quiet. Many residents remember that day vividly, but for hundreds of thousands of Washingtonians it’s just a story, either because they have moved here since, or are too young to remember. Most of my students at the University of Washington were just being born around then. The passing of decades quickly lulls us into a false sense of complacency, but another earthquake just like Nisqually — or worse — could happen at any time. Knowing that the 1949 and 1965 quakes were very similar to the one in 2001, seismologists believe that chances are better than even that another Nisqually will happen in the coming few decades.
Recently, there has been a lot of focus on the potential for the “Big One” — a giant offshore magnitude 9 earthquake and tsunami. When that occurs, it will be a calamitous day, and we must certainly anticipate and prepare for it. However, the last time the Cascadia subduction zone fault moved was Jan 26, 1700; on average this happens about every 300-750 years. So, while a giant coastal quake could happen at any time in the next couple of centuries, another like Nisqually will likely happen in mere decades. The Seattle Fault and others like it present hazards, too, but large earthquakes on each of them seem to occur more like every few thousand years.
In short, in our lifetimes Washingtonians are actually most likely to experience another event like Nisqually.
Our region has made real, tangible strides in preparing for the next one, like replacing the Alaskan Way Viaduct with the Highway 99 tunnel and seawall and developing an exciting new earthquake early-warning system. However, I am concerned that as the time since our last earthquake stretches longer, the sense of urgency we felt to upgrade old structures, especially the thousands of older brick buildings (unreinforced masonry) and brittle reinforced concrete construction in Washington, is gradually fading. We can’t let that happen. These buildings need to be retrofitted to become more resilient to any and all future quakes.
Let’s renew our efforts to address the known hazards of those older buildings and critical infrastructure. Just as importantly, we need to ensure the solutions distribute the costs fairly and equitably and does not further exacerbate the housing crisis. Furthermore, we need stronger investment in research focused on the seismic hazards of our region, many of which are unique within the continental U.S.
The long-term prosperity of our region depends on both of these efforts. The pandemic has vividly shown us the perils of being underprepared for known risks. We must find the political will and commitment to build a safer future.
With no foreshocks, the Nisqually quake came seemingly out of nowhere on that Wednesday morning. That is the unique challenge of earthquakes compared to almost all other forms of natural hazard. Generated by the slow and silent motion of tectonic plates building up stress over decades and centuries, when a fault finally gives way, the earthquake strikes like a bolt from the blue releasing all that pent-up energy in mere seconds. While we can’t predict imminent earthquakes, and we certainly can’t prevent them, we do have clear and simple ways to prepare ourselves and make our society resilient to the inevitable shaking. The first level is personal: Prepare an emergency kit for yourself and those close to you that includes food and supplies for two weeks, as well as a family emergency plan.
Collectively, the best thing we can do is to strengthen our buildings, bridges and facilities. I have seen firsthand how this saves lives and gets society back on its feet quickly. This March 11 marks 10 years since the devastating Japan tsunami and earthquake, a first cousin to our prospective Big One. A few months after that disaster, I traveled to Sendai, Japan, a city only 75 miles from the epicenter, and saw for myself the devastation of the tsunami. But I also saw that the buildings and bridges there had come through the massive shaking of the quake itself with remarkably little damage and very few casualties except where the tsunami inundated the land.
Outside of the areas flooded by the tsunami, life was already back to something very close to normal. This is because Japan has woven earthquake readiness into all aspects of engineered society, building infrastructure that was and is resilient to these inevitable stresses.
We can and must do the same. That complacency from two decades without big earthquakes has slowed the pace of upgrading unreinforced masonry buildings, including schools, apartment complexes, factories and more. FEMA estimates the cost of future earthquakes to Washington and Oregon as $714 million for every year that passes. Committing resources now will save money and lives later.
We do have an exciting new way to provide precious seconds of advance warning. The U.S. Geological Survey, in partnership with our team at UW and other universities up and down the West Coast, has been working hard to build this new technology called ShakeAlert early warning. The system detects earthquakes just as the shaking hits the nearest few of our seismic sensors, then uses the lightning speed of modern data systems and computing power to issue a warning of impending shaking, within seconds, to areas at risk.
Similar warning systems exist in Japan, Chile and Mexico. Already fully operational in California, ShakeAlert is slated to begin public alerting (initially in a full-scale test mode) of large quakes in Washington and Oregon by May. All of us will be able to benefit from these warnings by taking protective actions such as to “Drop, Cover, and Hold On” upon receiving a cellphone alert. Furthermore, ShakeAlert can be used to trigger preprogrammed automated actions, such as activating PA systems at schools or closing valves to protect water systems. In fact, pilot versions of both of these examples are live today in our state. Automated uses of ShakeAlert will thus directly protect students, hospitals and critical infrastructure.
But ShakeAlert warnings are no substitute for fixing our most dangerous structures. As countries like Japan have shown us, we can and must use both structural upgrades and warnings to get through future earthquakes in the best possible shape.
Let’s get ready — not just for the Big One, but for the Next One.