“Volcanoes are now more closely monitored. We have a good chance now of determining when a volcano becomes restless,” says Don Swanson, a volcanologist reflecting on the lessons learned from the 1980 eruption of Mount St. Helens. Those words take on new heft as Mount Rainier, one of America’s most dangerous volcanoes, enters an unprecedented 72-hour period of near-constant volcanic tremor extended seismic hum that signals magma, hot water, and gas shifting deep within.
Seismometers on Rainier’s west flank recorded an almost unbroken roar beneath the surface since early Saturday. Instruments were showing a near-solid black band for most of the day by November 16, which indicates overlapping vibrations for 80 to 90 percent of the time. It’s not the sharp jolt of a tectonic earthquake but is rather a sustained high-energy signal often linked to magma movement. The US Geological Survey hasn’t yet raised the alert level: no ground swelling or eruption-triggering earthquakes have so far been detected. The duration of this tremor, though, is one of the longest in recent years, and Rainier remains classified at a “Very High” risk for eruption.
Yet the greatest danger is neither lava nor ash, but lahars-fast-moving volcanic mudflows that can obliterate whole communities in a matter of minutes. Historical data from Mount St. Helens records showthat lahars can reach above 30 meters per second and can carry huge chunks of debris over 80 kilometers downstream. These flows, fed by Rainier’s thick snowpack and loose volcanic rock, might be triggered by an eruption or a flank collapse-but also, some say, by intense rainfall. Past lahars have destroyed forests, washed out bridges, and buried roads beneath meters of dense slurry. Monitoring systems are in place: Rainier has lahar detection networks installed along key river valleys; these can trigger alarms and provide precious minutes for people downstream to reach higher ground.
Scientists use seismic data combined with ground deformation and gas emissions readings to make forecasts of activity, but even with the best available tools, reliable short-term predictions are seldom possible more than a few days in advance. For anyone in Rainier’s shadow, being prepared is never optional. Experts recommend knowing routes for possible evacuations, having stocked emergency kits on hand, and staying informed through official USGS and local emergency channels. Community drills at the local level are needed; hazard maps and public-awareness campaigns-most inspired by the disaster on Mount St. Helens-are critical in reducing risk.
As Swanson says, “All of this will save thousands of lives, maybe tens of thousands of lives.” The psychological strain from such uncertainty can be as real as the physical threat. Disaster psychologists recommend focusing on controllable actio, such as reviewingew family communication planspracticingce quick evacuations, anlimitingit exposure to sensationalized media coverage. Grounding techniques-such as deep breathing, mindful walks, or connecting with neighbors-can keep calm when seismic updates rule the news cycle.
History provides sobering context. In July, Rainier saw the largest recorded earthquakswarm, morere than 1,000 quakes in three weeks-far outpacing a 2009 swarm that lasted only three days. The 1980 eruption of Mount St. Helens, just 50 miles away, showed how quickly a restless volcano can escalate. That event’s lahars destroyed more than 200 homes and 185 miles of roads, with sediment still affecting river systems decades later. Yet there is also resilience in these landscapes. Where is the blast zone at St.
Helens was once stripped bare, but more than 150 species of plants now thrive. Recovery comes slowly by geologic standards, but it comes as a reminder that even after catastrophic change, renewal can occur. For the Pacific Northwest, the challenge is to take that long-view optimism and integrate it with readiness, so that when Rainier’s deep rumble shifts toward eruption, communities are not caught off guard.
