Aleutians
(52.0765, -176.1109)
WATCH 
Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Small earthquakes and numerous rockfalls were detected over the past day. Slightly elevated surface temperatures were observed through cloud cover over the past day. Clouds obscured webcam images.
The current lava eruption began in July 2021 and, since then, has filled most of the summit crater and advanced into valleys below. There have been no explosions at Great Sitkin Volcano since an event in May 2021. The volcano is monitored using local seismic and infrasound sensors, satellite data, webcams, and regional infrasound and lightning networks.
Instrumented
Aleutians
(54.7554, -163.9711)
ADVISORY 
Unrest continues at Shishaldin Volcano. Seismic and infrasound activity remains elevated, with numerous small earthquakes, seismic tremor, and infrasound signals observed over the past day. Sulfur dioxide emissions drifting to the northeast were detected in satellite data. Steam emissions were observed in webcam images; nothing was observed in satellite views of the volcano over the past day.
Local seismic and infrasound sensors, web cameras, and a geodetic network are used to monitor Shishaldin Volcano. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lightning data, and satellite images to detect eruptions.
Instrumented
Aleutians
(52.3309, -174.139)
Low-level unrest continues at the Atka volcanic complex with weak tremor and numerous small earthquakes observed in seismic data. Slightly elevated surface temperatures were observed in satellite views of the volcano over the past day. Weak sulfur dioxide emissions drifting to the southeast were also detected in satellite data.
The Atka volcanic complex includes several vents, including Korovin Volcano, Mount Kliuchef and Sarichef Volcano. Korovin has been the site of most historical eruptions that typically produce minor amounts of ash and occasional but small lava flows. The Atka volcanic complex is monitored by local seismic and infrasound sensors and webcam, satellite data, and regional lightning detection instruments.
Instrumented
