Alaska Volcano Observatory

No significant change occurred this week at Great Sitkin, where the ongoing eruption of lava within the summit crater continues. Seismic activity was low and unchanged from previous weeks, with occasional small volcanic earthquakes. Satellite views of the volcano were obscured by clouds much of the week, but occasional clear web camera views showed no unusual activity. 

The current, prolonged period of lava eruption at Great Sitkin Volcano began in July 2021 and has mainly been observed using satellite radar images that can view the volcano through cloud cover. A single explosive event occurred in May 2021; no other explosions have been detected since that time. 

Low-level unrest continues at Shishaldin Volcano. Occasional small volcanic earthquakes, seismic tremor, and periods of infrasound were detected. Web camera images of the volcano show a persistent weak steam plume at the summit. Sulfur dioxide emissions were seen in satellite data on Friday, July 19. Such activity has characterized the post-eruption period of unrest over the past several months.  

Minor rock falls associated with collapse events from the unstable ground in and near the summit crater may generate small clouds of fine-grained dust that dissipate quickly near the summit. No significant eruptive activity has occurred since 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, lightning data, and satellite images to monitor the volcano.