Things are getting a bit spicy at Mount Spurr in Alaska, where geologists have been reporting an increase in seismic activity for almost a year. Based on the latest developments, officials are now bracing themselves for what could be an imminent eruption.
Located in the Aleutian Arc, Mount Spurr is an ice-covered stratovolcano complex that most recently erupted in 1992 and 1953. On March 7, a flyover conducted by the Alaska Volcano Observatory (AVO) detected elevated levels of sulfur dioxide and carbon dioxide emanating from the summit of Mount Spurr, as well as very high levels of carbon dioxide at a nearby satellite vent called Crater Peak.
New fumaroles – or gas vents – were also spotted at Crater Peak, leading the AVO to conclude that “a new pathway towards the Crater Peak vent has opened, and that fresh magma may rise and erupt there.” These suspicions are bolstered by the fact that hundreds of small, shallow earthquakes have been detected beneath Mount Spurr each week for the past year, with more than 3,400 tremors reported since April 2024.
“We cannot assign an exact timeframe for when an eruption will occur, if it does, but the increased gas emissions recorded on March 7 suggest that an eruption may occur in the next few weeks to months,” explained the AVO in a statement.
Both of the eruptions that occurred during the 20th century came from the Crater Peak vent, with the last known eruption from Spurr summit having taken place several thousand years ago. According to the AVO, “the most likely outcome of the current unrest is an explosive eruption (or eruptions) [at Crater Peak] like those that occurred in 1953 and 1992.”
“In this scenario, one or more explosive events, each lasting as long as a few hours, would produce ash clouds carried downwind for hundreds of miles and minor […] ashfall over southcentral Alaska,” explains the observatory. “The flanks of Mount Spurr likely would be swept by pyroclastic flows (hot avalanches) and impacted by ballistic showers. Mudflows (lahars) could inundate the upper Chakachatna River valley.”
Happily, the area around Mount Spurr – which lies some 120 kilometers (75 miles) west of Anchorage – is uninhabited, which means no one is likely to find themselves in the path of these deadly flows. What’s more, the AVO says that “if an eruption occurred, it would be preceded by additional signals allowing warning,” which means there’s little danger of anyone being caught unawares by the volcano.
