Alaska scientists take Mount Spurr off volcano alert list as eruption risk dwindles
- Alaska Beacon
- Aug 21
- 3 min read
Spurr erupted in 1953 and 1992, but it also gave similar misleading signs in 2004 and 2006
By James Brooks
Alaska Beacon
Alaska’s volcano experts no longer expect an eruption anytime soon from Mount Spurr, the closest active volcano to Anchorage.
On Wednesday, the Alaska Volcano Observatory formally lowered the alert level for Mount Spurr from yellow to green after months of declining activity.
“Things are OK right now, and hopefully that continues in the future,” said David Fee, coordinating scientist for the University of Alaska Fairbanks Geophysical Institute, which operates the observatory alongside the U.S. Geological Survey.
While the land immediately around Spurr isn’t inhabited, ash emitted from the volcano has disrupted life in Southcentral Alaska before. In 1953 and 1992, Spurr eruptions dumped ash on Anchorage, disrupting air travel.
Starting in February 2024, scientists had observed large numbers of small earthquakes beneath the volcano, and ground near it was deforming, surging upward. Ice atop the volcano melted, and air samples taken above the volcano showed signs of magma moving beneath the surface.
Scientists had been monitoring Crater Peak, a site south of Mount Spurr’s summit, as the likely spot of an eruption.
In October 2024, they raised the volcano’s alert level, and by March of this year, the volcano observatory said an eruption was “likely.”
But soon after that estimate, the signs of an imminent eruption began to diminish. There were fewer earthquakes, and the ground stopped rising as quickly as it had been.
Earlier this summer, the volcano observatory issued a statement saying that the odds of an eruption had fallen, and Spurr continued to quiet, leading to Wednesday’s announcement.
“What we’re seeing right now is all … really consistent with magma that intruded (beneath the volcano) and then stopped intruding. But it’s still creating some signals such as increased gas emissions and kind of weak seismicity,” Fee said.
While Spurr erupted in 1953 and 1992, darkening the skies over Anchorage with ash, it has also previously signaled an eruption that never came to pass.
In 2004 and 2006, the volcano showed signs of unrest for months but never erupted. The most recent period of unrest seems to resemble those two false starts.
Even though the volcano didn’t erupt, it has the potential to offer a scientific bonanza. AVO staff installed a network of seismic, infrasound and ground-measuring devices around Spurr, making it the most-monitored volcano in the state, according to the number of instruments listed on the AVO’s website.
“As we’re starting to look back now, at the period of unrest, it’s often just as interesting or scientifically valuable to understand why volcanoes don’t erupt, because they don’t, over half the time, approximately. Are there maybe some signals or something in our data that we can kind of tease out to help us understand why it didn’t erupt?” Fee said, looking back at what was learned.
“I think understanding why that occurred will be really important,” he said.
AVO and the Alaska Division of Homeland Security and Emergency Management also spent months educating Southcentral Alaskans about the possibility of ashfall, reminding them that they live in a volcanically active area.
That work will live on, too, Fee said, and people will be better informed the next time an eruption looks likely.
“Because they don’t happen that frequently in Cook Inlet, it was kind of a good reminder for people to be aware, to understand the hazards that are out there,” he said.
• James Brooks is a longtime Alaska reporter, having previously worked at the Anchorage Daily News, Juneau Empire, Kodiak Mirror and Fairbanks Daily News-Miner. Alaska Beacon is part of States Newsroom, the nation’s largest state-focused nonprofit news organization.
