USGS Volcano Notice - DOI-USGS-AVO-2025-04-24T19:37:33+00:00

The Iliamna monitoring network is down to a single station due to power issues caused by late winter snowfall. Data are insufficient to establish the state of the volcano. As a result, we are changing the Aviation Color Code and Volcano Alert Level to UNASSIGNED/UNASSIGNED. 

As snowmelt occurs it is likely that the stations will come back online as power recovers. We expect this could occur in the next few weeks. If outages persist we will conduct site visits to assess possible station damage and make repairs. 

The move to UNASSIGNED does not reflect a change in activity at the volcano, but rather a change in AVO’s ability to track volcanic activity. Though AVO’s monitoring is temporarily compromised, the most probable eruption scenario for Iliamna involves several months of intensifying earthquake activity before erupting, and prior to network failure, Iliamna was not showing any signs of unrest. 

However, with current monitoring network health, AVO is unable to provide timely eruption forecasts or quickly confirm or dismiss reports of activity. As with other Unassigned volcanoes, AVO will use satellite data, regional seismic, infrasound and lightning networks, and reports from pilots and ground observers to detect signs of unrest or eruptive activity. These monitoring data may detect ongoing eruptive activity, but AVO will be limited in its ability to identify precursory signals and provide early warning of impending eruptions.