ALASKA VOLCANO OBSERVATORY DAILY UPDATE
U.S. Geological Survey
Monday, July 8, 2024, 1:06 PM AKDT (Monday, July 8, 2024, 21:06 UTC)
No significant changes seen at Great Sitkin Volcano where lava continues to slowly erupt within the summit crater. Over the past day, a few earthquakes were detected beneath the volcano. Satellite radar image through July 7 shows continued very slow eruption of lava. Satellite and web camera views of the volcano have been obscured by clouds.
The current lava flow eruption began in July 2021. No explosive events have occurred since a single event in May 2021.
Local seismic and infrasound sensors and web cameras are used to monitor Great Sitkin along with regional infrasound and lightning networks and satellite data.
No major changes have occurred in the last day at Shishaldin Volcano where minor volcanic unrest continues. Small, low-frequency earthquakes and seismic tremor are occurring and during periods with low wind, minor infrasound signals are detected, possibly coming from very small explosions occurring deep in the volcanic conduit. Steaming from the summit was seen in web camera images.
Minor rock falls associated with gravitational collapse of the unstable ground in and near the summit crater may occur without warning. The collapse events can generate small clouds of dust likely composed of fine-grained ash. The diffuse dust clouds dissipate quickly and can produce irregular-shaped deposits near the summit. The last significant ash-producing eruption occurred in November 2023.
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.
No significant signs of unrest were observed over the past day. Seismicity has been quiet with a few small local earthquakes detected. Sulfur dioxide measured by local ground-based instruments indicate typical emission rates. Since this activity represents typical background behavior at Mount Cleveland, the Alaska Volcano Observatory lowered the Aviation Color Code to GREEN and Volcano Alert Level to NORMAL.
Cleveland volcano is currently monitored by a local seismic network, infrasound sensors, a gas sensor and web cameras. In addition to the local monitoring network, AVO uses nearby geophysical networks, regional infrasound and lighting data, and satellite observations to detect eruptions. Based on past events, explosive eruptions of Cleveland may occur with little or no warning. Rapid detection of an ash-producing eruption may be possible using a combination of seismic, infrasound, web camera, lightning, and satellite data.
Matt Haney, Scientist-in-Charge, USGS, mhaney@usgs.gov, (907) 786-7497
Tarsilo Girona, Acting Coordinating Scientist, UAFGI, tarsilo.girona@alaska.edu, (907) 378-5460
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.