Mount Spurr Volcano
Monitoring, Recent Eruptive History, and Ash Hazards
Mount Spurr is an ice- and snow-covered volcano located about 80 miles (129 km) from Anchorage, Alaska, on the west side of Cook Inlet. The volcano is 11,070 ft (3,374 m) tall and has two main vents–Mount Spurr summit and Crater Peak. On a clear day, Mount Spurr is easily viewed from Anchorage and the Kenai Peninsula.
Past Activity & Hazards
The Mount Spurr summit vent has not erupted for several thousand years. The Crater Peak vent has erupted recently–once in 1953, and three times in 1992. The 1953 and 1992 eruptions lasted between 3 and about 7 hours, were explosive, and produced columns of ash that rose more than 50,000 ft (15 km) above sea level. The ash clouds deposited minor ashfall (up to 1/4 inch or about 6 mm) over Southcentral Alaska communities. The ashfall caused temporary closures of airports, offices, and schools, and disrupted daily life. Cleanup costs in 1992 were nearly $2 million. In 2004–2006 and 2024–2025, Mount Spurr experienced episodes of increased earthquake activity, minor surface uplift, and increased heat flow that melted the summit ice. In 2004–2006, small debris flows were generated on the summit cone, but no eruption occurred. The 2024–2025 activity is ongoing. Hazards from Mount Spurr include airborne ash clouds and ashfall. Lahar (mudflow) and pyroclastic-flow (hot avalanches) hazards are confined to the main drainages on the volcano and generally pose no significant risk to communities.
Volcano Monitoring
Mount Spurr is one of the best monitored volcanoes in Alaska and has a network of instruments that send data in real time to AVO. Staff use satellite, seismic, deformation, and infrasound data to assess activity levels at all active volcanoes in Alaska, including Mount Spurr. Detailed records of eruptions, pilot reports, and monitoring data help AVO staff provide information before, during, and after a volcanic event.
Ash Hazards and How to Stay Informed
Airborne Ash Clouds
Drifting clouds of volcanic ash are a significant hazard to aircraft, making this the principal volcanic hazard in Alaska. Ash can cause severe damage to engines, windscreens, navigation systems, and other airplane parts. Airport closures, rerouting of flights, delays, and cancellations are all likely impacts of a Spurr eruption. AVO works closely with the Federal Aviation Administration (FAA) and the National Weather Service (NWS), who issue warnings about airborne volcanic ash to pilots.