USGS Volcano Notice - DOI-USGS-AVO-2026-07-16T12:42:57+00:00

AVO/USGS Volcanic Activity Notice

Volcano: Atka volcanic complex (VNUM #311160)

Current Volcano Alert Level: ADVISORY
Previous Volcano Alert Level: NORMAL

Current Aviation Color Code: YELLOW
Previous Aviation Color Code: GREEN

Issued: Thursday, July 16, 2026, 5:03 AM AKDT
Source: Alaska Volcano Observatory
Notice Number: 2026/A521
Location: N 52 deg 19 min W 174 deg 8 min
Elevation: 5030 ft (1533 m)
Area: Aleutians

Summary: Small phreatic (steam) explosion detected, Color Code and Alert Level raised to YELLOW/ADVISORY.

Volcanic Activity:

A small explosion from Korovin Volcano was detected in seismic and infrasound data at 3:55 am AKDT (11:55 UTC) this morning, July 16, 2026. The Aviation Color Code and Alert Level are being raised to YELLOW/ADVISORY. No emissions were observed in satellite images, but regional clouds would obscure activity below 10,000 feet (3 km) asl. Possible ash clouds generated by such events are expected to be small and dissipate quickly. Fallout of ash, if any, is unlikely to extend much beyond the upper flanks of the volcano.

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.

Contacts:

Matt Haney, Scientist-in-Charge, USGS, mhaney@usgs.gov (907) 786-7497

Jess Larsen, Acting Coordinating Scientist, UAFGI, jflarsen@alaska.edu (907) 378-5460

Contact AVO: https://avo.alaska.edu/contact

The Alaska Volcano Observatory is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.

VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)

WMAK01 PAVO 161303   
VONA
DTG:                    20260716/1303Z
VOLCANO:                ATKA VOLCANIC COMPLEX 311160
PSN:                    N5220 W17408
AREA:                   ALASKA
SOURCE ELEV:            5030FT AMSL
NOTICE NR:              2026/04
CURRENT COLOUR CODE:    YELLOW
PREVIOUS COLOUR CODE:   GREEN
SVO:                    ALASKA VOLCANO OBSERVATORY
ACT STS:                ERUPTION OCCURRED
ONSET:                  20260716/1155Z
DUR:                    10 MIN
VA CLD HGT:             0FT AMSL
HGT SOURCE:             SATELLITE
MOV:                    NO VA CLD PRODUCED
CTC:                    MATT HANEY SIC, USGS MHANEY@USGS.GOV (907) 786-7497 JESS LARSEN, ACTING-CS, UAFGI
                        JFLARSEN@ALASKA.EDU...
RMK:                    SMALL EXPLOSION DETECTED FROM KOROVIN VOLCANO. NO VA OBS ABV LOW MET CLD. NO ONGOING
                        ACTIVITY EXPECTED.
NXT NOTICE:             A NEW VONA WILL BE ISSUED IF COND CHANGE SIGNIFICANTLY OR IF THE COLOR CODE CHANGES
NNNN