An increase in seismic activity has been recorded at Mount Spurr, a stratovolcano located 124 kilometres west of Anchorage, Alaska. Over the past ten months, small earthquakes have been detected, with a noticeable rise in activity observed in recent weeks. Reports indicate that the earthquakes, which were initially concentrated near the summit, have shifted towards Crater Peak, a side vent that previously erupted in 1992 and 1953. Scientists suggest that this could signal the movement of magma beneath the volcano, potentially leading to an eruption. The likelihood of an eruption occurring at Crater Peak has been estimated at 50 percent, while the chances of an eruption at the volcano’s main crater remain low.

Potential Eruption Scenarios at Mount Spurr

According to the Alaska Volcano Observatory (AVO), the ongoing seismic activity could either lead to an eruption or subside without significant volcanic activity. Matt Haney, Scientist-in-Charge at AVO, told Live Science that the earthquake pattern has intensified, with tremors now concentrated in an area approximately 3 kilometres down the slope. This shift aligns with previous eruptions from Crater Peak, which ejected ash plumes reaching 20,000 metres into the atmosphere. Despite similarities to past events, volcanic unrest observed in 2004 and 2005 did not result in an eruption, demonstrating that increased seismicity does not always lead to an explosive event.

Possible Impact of an Eruption

If an eruption occurs, hazards such as pyroclastic flows, lahars, and ashfall could impact surrounding areas. While no communities are directly in the path of potential lahars or pyroclastic flows, disruptions to air travel could be significant. The 1992 eruption of Crater Peak led to the temporary closure of Anchorage’s airport and covered parts of the city in ash. Given the current volume of air traffic passing through Alaska, a similar event could cause major disruptions to transcontinental flights. Scientists are monitoring the situation closely, particularly for signs of prolonged seismic tremors, which could indicate that an eruption is imminent.