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USGS Volcano Notice for Aviation - DOI-USGS-AVO-2025-05-05T17:00:22+00:00
| (1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) | |
| (2) Issued: | (20250505/2000Z) |
| (3) Volcano: | Atka volcanic complex (VNUM #311160) |
| (4) Current Color Code: | GREEN |
| (5) Previous Color Code: | YELLOW |
| (6) Source: | Alaska Volcano Observatory |
| (7) Notice Number: | 2025/A289 |
| (8) Volcano Location: | N 52 deg 19 min W 174 deg 8 min |
| (9) Area: | Aleutians |
| (10) Summit Elevation: | 5030 ft (1533 m) |
| (11) Volcanic Activity Summary: |
No further explosive activity has been detected at the Atka volcanic complex since the small explosive event at 10:34 AKDT on April 25 (18:34 UTC on April 25). Thus, the Aviation Color Code and Alert Level are being reduced to GREEN/NORMAL. Brief explosive events at Korovin Volcano can occur without significant precursory unrest. Fallout of ash is unlikely to extend much beyond the upper flanks of the volcano.Possible ash clouds generated by such events are expected to be small and dissipate quickly. |
| (12) Volcanic cloud height: | n/a |
| (13) Other volcanic cloud information: | n/a |
| (14) Remarks: | The Atka volcanic complex forms the northern part of Atka Island, located about 16 km north of the community of Atka and 1,761 km southwest of Anchorage. The Atka volcanic complex includes a possible older caldera and several younger vents, including Korovin Volcano, Mount Kliuchef, and Sarichef Volcano. Korovin Volcano, a 1553-m-high (5030 ft) stratovolcano, has been the site of most historical volcanic activity, and has a small, roiling crater lake that occasionally produces energetic steam emissions. Korovin has erupted several times in the past 200 years, including 1973, 1987, and 1998, and has likely had small ash emissions as recently as 2005. Typical recent Korovin eruptions produce minor amounts of ash and occasional but small lava flows. Reports of the height of the ash plume produced by the 1998 eruption ranged as high as 10,600 m (35,000 feet) above sea level. Mount Kliuchef is composed of a series of five vents aligned northeast–southwest. The two main summit vents of Kliuchef appear relatively young and the easternmost was probably the source of an 1812 eruption that is sometimes attributed to Sarichef. |
| (15) Contacts: | Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497 |
| (16) Next Notice: | |