Semisopochnoi volcano (Aleutian Islands): activity increases, ash plumes rising to 15,000 ft
Mon, 20 Sep 2021, 06:5506:55 AM | BY: T
Ash plume from Semisopochnoi volcano rising above the weather cloud deck on Sentinel satellite imagery (image: Sentinel Hub)
The eruption has intensified and the alert status of the volcano was raised to the highest level RED. Ash emissions from the volcano have increased in frequency and intensity, and can be seen on satellite images rising above the weather clouds.
Current seismic recording (CEAP station / AVO)
The latest estimate was that the ash plume reached an altitude of 15,000 ft. above sea level, extending approximately 60 miles (100 km) to the southeast through 05:00 UTC this morning, the Alaska Volcano Observatory (AVO) reported:
"Explosions have been observed throughout the day and increased sulfur dioxide gas emissions have been observed in satellite data this afternoon. These observations represent an increase in eruptive activity and Aviation Color Code and Volcano Alert level are being increased to RED/WARNING.
Increasing high clouds over Semisopochnoi will likely obscure satellite views of ash emissions within the hour. Seismic and infrasound monitoring will continue to provide notice of ongoing explosive activity, however it cannot determine the height or extent of ash emissions. The Alaska Volcano Observatory will continue to closely monitor all available data." (AVO)