Ash plume over Mount St. Helens raises eruption fears as USGS says no eruption

An ominous haze of ash formed over Mount St. Helens on Tuesday, renewing fears that the long-dormant volcano could erupt. The U.S. Geological Survey said there is no eruption, but authorities noted that ash clouds were visible on satellite imagery and that pilots reported ash reaching heights of about 10,000 feet.

USGS officials attributed the ash to strong easterly–southeasterly winds lifting decades-old deposits from the crater and surrounding slopes. The agency stressed that this phenomenon is not the result of recent volcanic activity and that Mount St. Helens remains at Aviation Color Code GREEN and Alert Level NORMAL. The ash, while not a sign of imminent eruption, can be hazardous to aircraft and human health if inhaled.

Experts linked the event to a meteorological setup that pulled dry air and strong winds across the Cascades. A strong thermal trough over western Washington directed easterly winds across the volcano, with gusts estimated at 30 to 50 mph. The region has been unusually dry, with much of Washington and Oregon receiving far less than average rainfall in recent weeks, which helps expose loose volcanic ash to the wind; FOX Weather reported the dryness and gusty conditions contributed to the resuspension.

While Mount St. Helens is not currently erupting, the event comes amid a history of episodic activity. The volcano erupted on May 18, 1980, sending a plume of ash about 2.5 miles into the sky, triggering widespread devastation across parts of Washington, Idaho and western Montana. The eruption killed 57 people, destroyed more than 200 homes, and unleashed downstream hazards such as lahars that closed bridges and disrupted rail lines. In the years since, scientists have kept a vigilant watch for signs of renewed unrest, including earthquakes, ground deformation and gas emissions.

Seismologists have tracked renewed seismic activity in recent years, with hundreds of quakes recorded over multi-month periods in 2023 and 2024. In early June 2024, the number of earthquakes per week peaked at about 38, most of which were smaller than magnitude 1.0; the largest quake felt at the volcano was magnitude 2.0 on May 31, 2024. Experts say that such activity often reflects magma movement deep underground and a process known as recharge, where magma enters a reservoir located several miles below the surface. But monitoring teams caution that elevated quake rates do not automatically signal an eruption.

Officials at the Cascades Volcano Observatory have stressed that short-term increases in earthquake rates are common components of background seismicity at Mount St. Helens. They noted that the recent sequences—though among the largest since the last eruption ended in 2008—have not been accompanied by significant changes in ground deformation, volcanic gas, or thermal emissions that would indicate an imminent eruption. No other monitoring parameter has shown notable changes, the observatory said, and there is no current hazard shift associated with this activity.

The U.S. agencies monitoring the volcano say they will maintain round-the-clock surveillance, with data from seismometers, gas sensors and web cameras feeding into daily updates. If new signs emerge—such as ground deformation, elevated gas emissions or persistent lava movement—authorities would issue updated warnings and advisories. In the meantime, aviators and residents are advised to treat the ash as a potential hazard when wind-driven dispersal brings fine particulates into airspace or habitable areas.