Magnitude 4.6 Earthquake Strikes Near Alaska Mount Spurr Amid Eruption Unrest

A magnitude 4.6 earthquake struck near Petersville, Alaska, just miles from Mount Spurr, a volcano currently under 'Advisory' status due to signs of unrest and potential eruption. The quake, occurring about 52 miles underground and approximately 34 miles north of Skwentna, was felt across Anchorage and the Matanuska-Susitna region despite the epicenter being over 100 miles away from Anchorage. Nearly 200 reports of shaking were submitted to the US Geological Survey from this sparsely populated area, which lies above the active Broad Pass thrust fault, posing a potential seismic hazard with the possibility of larger magnitude earthquakes. Research indicates that volcanoes like Mount Spurr, already showing low-level disturbances and minor earthquakes, can be triggered into eruption by nearby seismic activity, especially when magma pressure and underground gas buildup are factors. Residents across Anchorage shared their experiences of the shaking, highlighting continued local concern as Mount Spurr remains closely monitored following a March 2025 warning that an eruption could occur at any time. The Alaska Volcano Observatory continues to observe small quakes and minor vapor emissions from the volcano's summit, maintaining vigilance amid the heightened seismic activity.