Supervolcano Ready To Explode? Mount St. Helens Reawakens, Continues To Rebuild Itself

Scientists with the U.S. Geological Survey are marking the 10-year-anniversary of Mount St. Helens’ reawakening to remind people that Mount St. Helens will continue to rebuild itself.

The Associated Press reports that 10 years ago this week, Mount St. Helens awoke from an 18-year geological slumber. Since that time, scientists have been heavily monitoring the area to pinpoint when the next eruption will take place. Geologists expect future dome-building eruptions at the volcano. USGS seismologist Seth Moran says an exact estimate for eruption is not yet fully known.

“It looks like Mount St. Helens is getting ready to erupt again and it can happen in the order of years to decades.”

The USGS confirms that Mount St. Helens has a renewed potential for volcanic activity on the volcano watch page.

“Mount St. Helen’s high frequency of eruptions during the recent geologic past and its two eruptive episodes of the past three decades indicate a high probability of renewed eruptive activity. In addition, the volcano has produced four large explosive eruptions during the past five centuries that affected the Pacific Northwest region and sent large amounts of volcanic ash downwind. Owing to these factors, USGS maintains a robust monitoring program at the volcano to detect signs of renewed unrest and works with Federal, State, and local agencies to develop crisis plans and risk-mitigation strategies. Businesses and citizens should be aware of potential future hazards and consult with local emergency-management agencies for advice on how to prepare for volcano and other types of natural hazards.”

Mount St. Helens Lava Flow Map
Mount St. Helens, Washington simplified hazards map showing potential impact area for ground-based hazards during a volcanic event.

Though signs are pointing to an eruption in the near future, Moran notes that “this doesn’t mean it’s getting ready to erupt.”

“The balloon has inflated, and it could stay inflated for decades. What we can say, is when it is ready to erupt, we will know.”

The observatory tracked a similar refueling pattern beneath Mount St. Helens during the volcano’s quiet period in the 1980s and 1990s, Moran said. However, the earthquakes were deeper during the first quiet period, at about four to five miles below the surface, and the magma refueled faster, according to the new results. Scientists keep a close eye on the Washington volcano, which has erupted on and off since its deadly 1980 blast. Studies of past eruptions suggest Mount St. Helens is more likely to spend the next few hundred years rebuilding the peak that was lost in the large 1980 eruption. The good news is this means that the volcano is expected to use eruptions to rebuild as opposed to blowing a large portion of the country to an ashy wasteland.

Even so, the signals from the slumbering volcano are a message to be ready for the next eruption, however small, the researchers said.

“We’re like the fire department. We’ve got to be ready to go.”