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USGS Volcano Notice - DOI-USGS-AVO-2025-08-25T19:59:40+00:00
ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Monday, August 25, 2025, 12:16 PM AKDT (Monday, August 25, 2025, 20:16 UTC)
GREAT SITKIN (VNUM #311120)
52°4'35" N 176°6'39" W, Summit Elevation 5709 ft (1740 m)
Current Volcano Alert Level: WATCH
Current Aviation Color Code: ORANGE
Lava continues to erupt in the summit crater of Great Sitkin Volcano. Small earthquakes and rockfall signals were detected over the past day. Satellite and web camera observations were obscured by clouds.
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 and web cameras, and regional infrasound and lightning networks.
To view monitoring data and other information about Great Sitkin: https://avo.alaska.edu/volcano/great-sitkin
SHISHALDIN (VNUM #311360)
54°45'19" N 163°58'16" W, Summit Elevation 9373 ft (2857 m)
Current Volcano Alert Level: ADVISORY
Current Aviation Color Code: YELLOW
Over the past month, signs of volcanic unrest at Shishaldin Volcano have been gradually increasing. Sulfur dioxide emissions have increased, a more vigorous gas plume from the summit crater has been observed, and seismic and infrasound data have shown moderate increases in both the number of events and their amplitude.
These observations represent a departure from background behavior and the Aviation Color Code and Volcano Alert Level was increased to YELLOW/ADVISORY earlier today.
Small earthquakes and infrasound signals were detected by the local monitoring network over the past day, and strong sulfur dioxide emissions were detected by satellite sensors. Webcam views were mostly obscured by clouds, but the gas plume was visible at times when the clouds cleared.
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 lighting data, and satellite images to detect eruptions.
CONTACT INFORMATION:
Matt Haney, Scientist-in-Charge, USGS mhaney@usgs.gov (907) 786-7497
David Fee, Coordinating Scientist, UAFGI dfee1@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.