Alaska’s Mount Spurr on the brink: Scientists warn of imminent eruption near Anchorage

By willowt // 2025-03-14

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Mount Spurr, located 80 miles northwest of Anchorage, is showing signs of potential eruption due to elevated volcanic gas emissions, reactivated gas vents and seismic activity, indicating magma intrusion beneath the volcano.
The volcano last erupted in 1992, producing massive ash clouds that disrupted air travel and affected communities as far as Greenland. Its 1953 and 1992 eruptions were brief but impactful, with ashfall causing respiratory issues and machinery damage.
Recent data shows a sharp rise in sulfur dioxide (SO2) and carbon dioxide (CO2) emissions, along with over 3,400 shallow earthquakes and ground deformation, suggesting magma is moving closer to the surface.
The most likely outcome is an explosive eruption similar to past events, producing ash clouds, minor ashfall and potential pyroclastic flows or mudflows. Other possibilities include a smaller eruption, a failed eruption, or—though unlikely — a larger explosive event.
Scientists cannot predict the exact timing of an eruption but are monitoring for additional warning signs. Authorities urge residents and travelers to stay informed, as an eruption could occur with little to no advance notice, posing risks to health, aviation and nearby areas.

Alaska’s Mount Spurr, a towering volcano located just 80 miles northwest of Anchorage, is showing alarming signs of activity, with scientists warning that an eruption is “likely” in the coming weeks or months. The Alaska Volcano Observatory (AVO) reported significantly elevated volcanic gas emissions and newly reactivated gas vents during recent observational flights on March 7 and 11. These findings suggest that magma is intruding into the Earth’s crust beneath the volcano, increasing the probability of an explosive event. “The latest evidence indicates that an eruption is likely, but not certain, to occur within the next few weeks or months,” the AVO stated in a recent summary. This would mark the first eruption of Mount Spurr in over 30 years, with its last major activity occurring in 1992.

Historical context: A volcano with a fiery past

Mount Spurr is no stranger to eruptions. The volcano has erupted twice in modern history — once in 1953 and again in 1992—both times from its Crater Peak vent, located two miles south of the summit. These eruptions, though brief, produced massive ash clouds that rose up to 65,000 feet and drifted hundreds of miles downwind, depositing minor ashfall on communities in southcentral Alaska. The 1992 eruption, in particular, had significant impacts on daily life. Anchorage residents were advised to stay indoors or wear masks to avoid inhaling ash, which can cause respiratory issues and damage machinery. The ash cloud even reached as far as Greenland, temporarily grounding flights and disrupting air travel across the region. “The 1992 eruptions were a wake-up call for Alaska,” said John Power, a geophysicist with the U.S. Geological Survey at the AVO. “They reminded us that even a short-lived eruption can have far-reaching consequences.”

Current unrest: What’s happening beneath the surface?

The current unrest at Mount Spurr is driven by a buildup of magma beneath the volcano’s summit, which has been accumulating for several months. Recent overflights detected sulfur dioxide (SO2) emissions of about 450 metric tons per day—a sharp increase from less than 50 metric tons per day in December 2024. Elevated carbon dioxide (CO2) levels were also measured at the Crater Peak vent, a precursor to past eruptions. “The increase in gas emissions confirms that new magma has intruded into the Earth’s crust beneath the volcano,” the AVO noted. “The recent gas data suggest that a new pathway towards the Crater Peak vent has opened, and that fresh magma may rise and erupt there.” Seismic activity has also surged, with over 3,400 earthquakes recorded beneath Mount Spurr since April 2024. Most of these quakes are shallow, occurring less than 2.5 miles below sea level, and have reached magnitudes as high as 2.7. Ground deformation, measured by GPS stations, shows the land around the volcano has shifted outward by about 2.6 inches, further evidence of magma movement.

Potential scenarios: What could happen next?

The AVO has outlined four possible scenarios for Mount Spurr’s future activity, with the most likely being an explosive eruption similar to those in 1953 and 1992. Such an event would produce ash clouds capable of traveling hundreds of miles, minor ashfall in nearby communities, and potentially pyroclastic flows and mudflows (lahars) in the upper Chakachatna River valley. Other scenarios include a smaller, less explosive eruption, a failed eruption where magma stalls beneath the surface, or — though highly unlikely — a much larger explosive event. “The likelihood of a much larger eruption is currently low,” the AVO emphasized.

Preparing for the unknown

While scientists are closely monitoring Mount Spurr, predicting the exact timing of an eruption remains challenging. “We cannot assign an exact timeframe for when an eruption will occur, if it does,” the AVO stated. However, they expect to see additional warning signs, such as increased seismic activity, sustained tremor and further melting of snow and ice, as magma moves closer to the surface. In the meantime, Alaskan authorities are urging residents and travelers to stay informed. “It is also possible that an eruption could occur with little or no additional warning,” the AVO cautioned. This would pose significant risks to hikers, pilots and anyone in low-lying areas near the volcano, where elevated CO2 and SO2 levels could be hazardous.

A reminder of Nature’s power

Mount Spurr’s unrest serves as a stark reminder of the dynamic and unpredictable nature of volcanic activity. For Alaskans, who live in a state with 53 historically active volcanoes, this is a familiar reality. Yet, each eruption carries unique challenges, from disrupted air travel to potential health hazards. As scientists continue to monitor Mount Spurr, their work underscores the importance of preparedness and vigilance in the face of natural forces. For now, all eyes are on this icy giant, waiting to see if it will awaken once more. Sources include: NYPost.com Avo.Alaska.edu NBCNews.com