High-level eruption at Shishaldin volcano, Alaska

An ash cloud from Shishaldin Volcano reaching 12 km (40 000 feet) above sea level was observed in satellite data at 13:50 UTC on October 3, 2023.

This follows a several-hour increase in observed eruptive activity, and a recent sharp increase in infrasound, seismicity, and lighting detections.

In response, the Aviation Color Code is being raised to Red and the Volcano Alert Level is being raised to Warning. The National Weather Service has issued a SIGMET for this ash cloud.

Based on previous eruption cycles, significant ash emissions are likely to continue for several hours. Pyroclastic and mudflows are likely on the immediate flanks of the volcano.

Eruptive activity began to increase significantly at around 05:00 UTC today. Around the same time, satellite images showed an increase in surface temperature consistent with lava fountaining, which was confirmed in clear web camera images. This fountaining has produced small hot avalanches of rock and lava down the slope of the volcano.

References:

¹ AVO/USGS Volcanic Activity Notice for Shishaldin volcano – Tuesday, October 3, 2023, 6:12 AM AKDT

² AVO/USGS Volcanic Activity Notice for Shishaldin volcano – Issued Monday, October 2, 2023, 11:43 PM AKDT

Featured image: Shishaldin volcano at 02:34 UTC on October 3, 2023. Credit: USGS/AVO

If you value what we do here, create your ad-free account and support our journalism.