Remember Mount St. Helens and heed the lessons learned

THIRTY-six years ago this week, Mount St. Helens erupted in Southwestern Washington, devastating an area larger than Seattle, Bellevue and Redmond combined. Fifty-seven people died in the eruption, some more than 15 miles from the volcano’s summit. The bodies of nearly half of those killed were never found and remain buried around the mountain.

After the eruption, Gov. Dixy Lee Ray and President Jimmy Carter claimed that the victims ignored warnings and were in danger zones illegally, but these statements were incorrect. Only three of the dead were in the area designated by the state as off-limits, and two of them had permission to be there. The only person in the danger zone illegally was the one person people tend to remember from the eruption: 83-year-old curmudgeon Harry R. Truman, who refused to leave his lodge on the shores of Spirit Lake.

Geologists and public-safety officials learned a lot from the eruption of Mount St. Helens. Volcanologists have become much better at predicting when volcanoes will erupt, which has saved lives at subsequent eruptions around the world. And state and local officials will always have Mount St. Helens as a reminder of the need to establish adequate danger zones and keep people out of them.

But some of the most important lessons from the 1980 eruption are still going unheeded. The massive eruption of Mount St. Helens was a low-probability, high-consequence event, which inevitably creates uncertainty in how to prepare. But we face events here in the Pacific Northwest that have a high probability and very high consequences for which we still are not ready.

As The Seattle Times is reminding us with its series of reports on earthquake hazards, the Pacific Northwest regularly undergoes earthquakes much larger than any experienced since Seattle’s founding. A coastal megaquake caused by the same tectonic process that fuels Mount St. Helens has a one-in-seven chance of occurring in the next 50 years. Less frequent but even more destructive earthquakes can occur on fault lines that run under Seattle, Tacoma and other populated areas.

Simulations of large earthquakes point to thousands of deaths, overwhelming numbers of injuries and many billions of dollars in damages. The long-term and collective risk is that the region could sink into an economic and psychological depression that would take decades to lift.

But fatalism about geological hazards here in the Northwest is misplaced. Evidence from elsewhere demonstrates that this region could not just survive a megaquake but emerge from such a disaster stronger, more resilient and more confident than ever. As Daniel Gilbert and Sandi Doughton documented in their May 15 special report, “Seismic Neglect,” we could emulate the strong actions that California and Oregon have taken to shore up unreinforced masonry buildings.

Parts of Japan endure equally strong earthquakes, but buildings, utilities and roads have been designed to withstand world-class shaking. (The 2011 Tohoku earthquake was an anomaly, because it was stronger than geologists had thought possible in that part of Japan.) A few coastal towns in Washington and Oregon have begun building rooftop structures where residents can take shelter from the tsunami that will follow a coastal megaquake.

At the University of Washington, the multidisciplinary M9 Project is calculating how much such an earthquake would shake different parts of our region, what that shaking would do and how best to prepare. The 2012 Resilient Washington State report set the goal of making the state resilient to earthquakes within the next 50 years, which at least establishes a framework for action. What’s needed now is the political will to embrace and act on existing recommendations.

Future earthquakes in the Pacific Northwest — and future volcanic eruptions — are inevitable. As with Mount St. Helens’ eruption, the consequences of those disasters will depend on decisions made before they occur.