Experts monitor increased activity at Mount Spurr

MOUNT SPURR, ALASKA — A volcano near Alaska’s most populous city could be on the brink of eruption after exhibiting signs of unrest over the past 10 months, according to experts.

Hundreds of small earthquakes have been detected beneath Mount Spurr, situated in the volcanically active Aleutian Arc about 75 miles west of Anchorage, the Alaska Volcano Observatory reports.

Signs of potential eruption

David Fee, a coordinating scientist at the observatory, noted that researchers have observed ground deformations at the volcano, a key indicator of potential magma movement.

“Basically, as we think magma and fluids rise within the earth, it causes the ground to swell or deform,” Fee told CNN on Saturday. The movement of magma and other fluids can also increase temperatures in surrounding areas on their way to the surface.

“A small lake has formed within the crater, and there’s some warmer water and gas coming out as well,” Fee added, suggesting further volcanic activity beneath Mount Spurr’s summit.

Despite these indicators, experts caution that there is no definitive way to predict if or when an eruption will occur within days, weeks, or months. Scientists continue to monitor the volcano closely for increased activity, such as rising water temperatures and the melting of snow and glaciers.

Assessing the eruption risk

As of now, experts estimate a 50-50 chance that Mount Spurr will erupt.

Because there are no cities or communities immediately near the volcano, “there’s no kind of local threat,” Fee explained.

However, a potential eruption could produce significant ash clouds, impacting air travel and causing ashfall in regional communities, including Anchorage.

“One or more explosive events lasting one or a few hours would produce ash clouds carried downwind for hundreds of miles, and the uninhabited area around Mount Spurr would be inundated by pyroclastic flows, mudflows, and ballistic showers,” the observatory stated in a February 6 update.

As of February 15, Mount Spurr’s volcano alert level remains at “Advisory,” one step above normal.

Historical eruptions at Mount Spurr

Mount Spurr last erupted in 1953 and three times in 1992, with all of these eruptions occurring at the Crater Peak vent, located two miles south of the volcano’s summit, according to the observatory.

“These eruptions were relatively small but explosive, and they dispersed volcanic ash over areas of interior, south-central, and southeastern Alaska,” the US Geological Survey reported.

The 1953 eruption sent ash columns soaring up to 65,000 feet above sea level and deposited about 6 mm of ash in Anchorage.

In 1992, one eruption forced the temporary closure of Ted Stevens Anchorage International Airport for 20 hours, with air-quality alerts issued for several days afterward.

Fee noted that a present-day eruption would likely occur at Crater Peak again.

“There has been no eruption from the summit of Spurr in thousands of years, … so that’s one of the reasons we think it’s more likely to erupt (from Crater Peak),” he said.

Scientists remain vigilant, analyzing data to determine whether Mount Spurr is indeed on the verge of another eruption.