Mount Spurr feeling restless, observatory says

The Alaska Volcano Observatory reports that Mount Spurr remains in a state of volcanic unrest, as it has since last April, characterized by ongoing earthquake activity, surface deformation, and volcanic gas emissions.

Seismic activity has slightly increased compared to last week, with 145 earthquakes detected over the past seven days, primarily in the summit region and a smaller number near Crater Peak.

Mount Spurr, located about 75 miles northwest of Anchorage, stands 11,070 feet tall. An eruption could have a significant impact on air traffic to area airports, including Ted Stevens Anchorage International Airport, which is the third busiest cargo airport in the world, measured by tonnage. The highest volcano of the Aleutian Chain, it last erupted in 1992, shutting down the Anchorage International Airport for 20 hours.

Although no unusual activity has been observed in satellite or webcam data, minor steam emissions from the summit have been occasionally visible from nearby communities during periods of clear weather, the observatory said.

Recent overflights on March 7 and 11 measured elevated levels of sulfur dioxide (SO2) and carbon dioxide (CO2) emissions from the summit of Mount Spurr, with additional CO2 emissions and reactivated gas vents observed within the crater at Crater Peak.

AVO released a statement earlier this week outlining these observations and reaffirming that the volcano remains under close monitoring. The Mount Spurr monitoring network is fully operational, though the webcam at station CKT remains obscured by snow and ice.

AVO continues to track activity using a variety of monitoring techniques, including local seismic, infrasound, and geospatial stations, as well as regional infrasound, lightning networks, and satellite data.

If magma were to move closer to the surface, additional changes in seismic activity, ground deformation, the summit lake, and fumaroles would be expected. These signals would provide advance warning in the event of an impending eruption.

While the current activity does not indicate an imminent eruption, AVO said that one may occur within weeks or months, as the unrest at the volcano has been building since last year. In October, the observatory raised the warning signal to yellow, due to the increased activity detected.

Learn more about Mount Spurr’s current activity at the Alaska Volcano Observatory.