Newest Volcano Notice Including Okmok

AVO/USGS Volcanic Activity Notice

Volcano: Okmok (VNUM #311290)

Current Volcano Alert Level: NORMAL
Previous Volcano Alert Level: UNASSIGNED

Current Aviation Color Code: GREEN
Previous Aviation Color Code: UNASSIGNED


Issued: Wednesday, September 10, 2025, 12:23 PM AKDT
Source: Alaska Volcano Observatory
Notice Number: 2025/A552
Location: N 53 deg 23 min W 168 deg 9 min
Elevation: 3520 ft (1073 m)
Area: Aleutians

Volcanic Activity Summary:

Data flow from the seismic network at Okmok volcano has been restored to allow local monitoring. The Aviation Color Code is now GREEN and the Volcano Alert Level NORMAL.

Recent Observations:
[Volcanic cloud height] none
[Other volcanic cloud information] none
[Ballistics] none
[Lava flow/dome] none
[Lava flow] none

Hazard Analysis:
[General hazards] none
[Ash cloud] none
[Ashfall] none
[Lava flow/dome] none
[Pyroclastic flow] none
[Mud flow] none
[Volcanic gas] none
[Other hazards] none
[Lava flow] none

Remarks:

Okmok volcano is a 6-mile-wide caldera that occupies most of the eastern end of Umnak Island, located 75 miles southwest of Unalaska/Dutch Harbor in the eastern Aleutian Islands. Okmok has had several eruptions in historic time typically consisting of ash emissions occasionally to over 30,000 feet ASL but generally much lower; lava flows crossed the caldera floor in 1945 and 1958. Prior to 2008, the volcano last erupted in February 1997 producing lava flows and intermittent ash emissions over the course of several months. The nearest settlement is Nikolski, population about 35, roughly 45 miles west of the volcano.

Contacts:

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

David Fee, Coordinating Scientist, UAFGI dfee1@alaska.edu (907) 378-5460

Next Notice:

A new VAN will be issued if conditions change significantly or alert levels are modified. While a VAN is in effect, regularly scheduled updates are posted at http://www.avo.alaska.edu

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.