USGS Volcano Notice for Aviation - DOI-USGS-AVO-2024-07-05T18:35:33+00:00

Sulfur dioxide gas emissions were detected on local gas monitoring sensors at Mount Cleveland starting June 21 with an increase in emission rate June 24–30. Although sulfur dioxide emissions declined to background levels on July 1, moderately elevated surface temperatures and vigorous steaming at the summit of the volcano observed over the past couple of days, suggest that Cleveland is in a state of volcanic unrest prompting the Alaska Volcano Observatory to upgrade the Aviation Color Code to YELLOW and Volcano Alert Level to ADVISORY.  

The last eruptive activity at Mount Cleveland was a short-lived explosion during the evening (local time) of June 1, 2020. Despite the current pause, the eruptive period at Mount Cleveland, dating back to 2001, remains ongoing and future explosions are likely. These have occurred without warning and typically generate small clouds of volcanic ash that are a hazard in the immediate vicinity of the volcano, though more significant ash emissions are possible.

Mount Cleveland is currently monitored with a five-station real-time seismic network. Based on past events, explosive eruptions of Cleveland may occur with little or no warning. Rapid detection of an ash-producing eruption may be possible using a combination of seismic, infrasound, lightning, and satellite data.