Keeping an eye on an Alaskan volcano

Volcano activity in Alaska ‘Spurrs’ talk about Washington volcanic ash safety

Brian Terbush
Volcano Program Manager at Washington Emergency Management Division

Mount Spurr is an active stratovolcano about 80 miles from Anchorage, Alaska. It has been in an ongoing state of volcanic unrest for many months now, and the Alaska Volcanoes Observatory believes it is very likely to erupt soon — but it won’t have much impact for our state. You can learn more about the status of this closely-monitored volcano at Alaska Volcano Observatory | Spurr(Opens an external site in a new window).

The major concern from an eruption at Mount Spurr would be volcanic ash – something that many people in the Pacific Northwest are familiar with, thanks to the May 18, 1980, eruption of Mount St. Helens, 45 years ago this May, which darkened the sky and spread a thin layer of ash over much of the area. This resulted in a long and difficult clean-up. Subsequent eruptions through September of that year also caused ashfall in other areas of Washington and Oregon.

Does this eruption in Alaska have any potential to impact us here in Washington?

Answer: No. It’s just too far away from us.

Mount Spurr is not the kind of volcano that has eruptions large enough to spread ash that far. Even an eruption as large as the May 18 eruption of Mount St. Helens occurring at Mount Spurr would have very little chance of causing us any direct problems, like ash falling on the ground.

So why are people in Alaska concerned and watching this volcano carefully?

Eruptions from Mount Spurr have the potential to disperse volcanic ash into the air that could reach the city of Anchorage, one of Alaska’s most populated cities, and could cause a nuisance for the people there. As a result, emergency managers in Alaska at the state, federal and local levels are working with the Alaska Volcanoes Observatory to help prepare their people for the potential of volcanic ashfall, and what they can do about it. Here is some information they’ve shared where you can learn more here(Opens an external site in a new window).(Opens an external site in a new window)

Also, with eruptions potentially blasting ash into the air, there is an additional concern: eruptions could potentially cause impacts to airplane traffic. The area around Alaska is heavily used by flights traveling across the Pacific Ocean. Close monitoring of volcanic ash from eruptions in Alaska is important because Alaska is also home to 86 of the 161 active volcanoes that the USGS monitors in the United States – more than half of them!

Ash is made up of tiny glass particles. And a jet engine is hot enough to melt glass. As a result, ash can melt as it enters jet engines, then resolidify throughout the engine as it cools, causing damage. Many of us remember the major impacts of the 2015 eruption of Eyjafjallajökull volcano in Iceland, which grounded air traffic across Europe for a week, just to avoid this potential danger to flights.

This is why volcanic ash paths are carefully monitored by the National Weather Service and USGS Volcano Observatories, as well as international groups of Volcanic Ash Advisory Centers around the world.

So the volcano won’t have any direct impacts to Washington, though an eruption might have us divert some flights. What do we need to know about it here in Washington?

This is a good reminder that Washington state is home to five active volcanoes, and each has its own hazards during eruptions, including volcanic ash.

When it comes to volcanic ash in Washington, our two most explosive volcanoes that can produce the most ash are Mount St. Helens and Glacier Peak – both of which have had major eruptions in the past sending ash across the U.S. or Canada, and far outside Washington. Mount Rainier, Mount Adams, and Mount Baker are also capable of explosive eruptions, and while the ash won’t travel as far, if you live nearby, it’s important to be prepared for ashfall, since where it goes depends on which way the wind blows.

We know these are hazards. Now, while our volcanoes are not erupting, is the best time to learn about and prepare for them. This is also why we're updating our coordination plan for Mount St. Helens and Mount Adams.(Opens in a new window)

Volcanic ash is a hazard that is a nuisance in small amounts, but can be dangerous in heavy amounts (several inches or more). Just four inches of wet volcanic ash becomes heavy enough to collapse most roofs.

Volcanic ash is made up of small pieces of silica, or glass – it is abrasive, it is conductive of static electricity, and it is very easy to remobilize in the air once it is on the ground. The ash can cause some problems to machinery and be irritating to those with respiratory illnesses, like asthma.

When volcanic ash is falling from the sky, it is best to remain indoors, sheltered in place, until it stops falling, to avoid breathing in excessive amounts of these small particles. Having a mask, like a well-fitting N-95, or even just putting a cloth over your nose and mouth can help reduce the likelihood of inhaling too much and irritating your lungs.

If volcanic ashfall is forecast for your area, it’s also a good idea to try to cover sensitive electronics. These small, abrasive particles can get into car engines, fans, or other electronics and cause damage.

When it comes to volcanic ashfall, it’s not as big of an immediate danger as other hazards, like lahars, or volcanic mudflows, which can happen at any of our volcanoes – but it is a complicated one that can potentially cause issues to a lot of systems and have some unforeseen impacts. Learn more about Volcanic Ash hazards, impacts, and mitigation from the USGS at https://volcanoes.usgs.gov/volcanic_ash/(Opens an external site in a new window). Taking the time now to learn more about these hazards can help you prepare for a future volcanic eruption.

Fortunately, all of our volcanoes in Washington are well-monitored, and we will have warning before they erupt. Sometimes this warning period of unrest can last a long time. In the case of Mount Spurr, the volcano has been in a state of “Watch,” or “Volcano is exhibiting heightened or escalating unrest with increased potential of eruption, timeframe uncertain,”(Opens an external site in a new window) since October of 2024, so for almost six months!

All five of Washington’s Volcanoes are currently at “normal,” or background levels of activity, so they are not currently seen as moving toward eruption, even though many have daily small earthquakes. But scientists continue to constantly watch them for any signs of that changing so we can be warned. You can sign up for a free Volcano Notification Service so that you can learn as soon as that normal status changes, directly from the scientists monitoring them. Find the link to Volcano Notification Service, and your local alerts at https://mil.wa.gov/alerts(Opens in a new window).

There is still a small chance that Mount Spurr won’t even erupt at all. There is a lot of uncertainty involved in volcanic eruptions, but at this point, scientists see that chance as very small and urge the people nearby to prepare in case the wind blows ash onto them. I wish them the best and for minimal impacts in the event of an eruption.

Meanwhile, since we will eventually be in a similar situation in Washington, take the time now to learn about our volcanoes and how we can prepare for their unique hazards, to be more prepared for a future eruption, by visiting https://mil.wa.gov/volcano(Opens in a new window) today!

Have questions? Email public.education@mil.wa.gov