Alert Level for Korovin volcano, Alaska raised to Advisory
A small explosion occurred at Korovin volcano on Atka Island, Alaska, at 21:27 AKDT on October 29, 2025, prompting the Alaska Volcano Observatory to raise the Aviation Color Code and Alert Level to Yellow / Advisory.
Korovin volcano. Image credit: AVO
A minor explosion from the Korovin volcano, part of the Atka volcanic complex in the central Aleutian Islands, was detected by seismic and infrasound instruments at 21:27 AKDT on October 29 (05:27 UTC October 30).
The Alaska Volcano Observatory (AVO) raised the Aviation Color Code from Green to Yellow and the Alert Level to Advisory.
The event did not produce a volcanic cloud, and fallout of ash is not expected to extend beyond the upper flanks of the volcano. Similar small explosive events have occurred at Korovin in the past without significant precursory unrest.
The Atka volcanic complex forms the northern portion of Atka Island, approximately 16 km (10 miles) north of the community of Atka and 1 760 km (1 090 miles) southwest of Anchorage. The complex includes a possible older caldera and several younger vents — Korovin, Mount Kliuchef, and Sarichef.
Korovin volcano is a 1 533 m (5 030 feet) stratovolcano and the site of most historical volcanic activity in the complex.
It contains a small, roiling crater lake that occasionally produces vigorous steam emissions. Historical records indicate eruptions in 1973, 1987, and 1998, with minor ash emissions reported as recently as 2005.
Typical activity at Korovin includes small explosions, limited ash emissions, and rare short lava flows. Reports from the 1998 eruption described ash plumes rising as high as 10 600 m (35 000 feet) above sea level.
Mount Kliuchef, another component of the Atka volcanic complex, consists of five aligned vents trending northeast–southwest. Its two main summit vents appear relatively young, and the eastern vent was likely the source of an eruption recorded in 1812, sometimes attributed to Sarichef Volcano.
References:
1 Volcano Observatory Notice for Aviation (VONA #2025/A656) – AVO – October 30, 2025
I am an Assistant Editor and Severe Weather & Science Journalist at The Watchers, specializing in real-time severe weather coverage, geophysical event reporting, and research-driven scientific analysis. You can reach me at rishav(at)watchers(.)news.
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