USGS Volcano Notice - DOI-USGS-AVO-2026-10-03T21:31:59+00:00

No further signs of unrest have been detected since the short‑duration explosion that occurred on October 1. Clouds obscured satellite views of the volcano over the past day.

Gareloi volcano persistently emits magmatic gases from a fumarole field on the south crater and commonly exhibits low-level seismic activity. These observations suggest the presence of shallow magma and potential interaction with a hydrothermal system. This October 1 explosion likely reflects a change to the magmatic-hydrothermal system, but it is not clear that the likelihood of a volcanic eruption has increased. AVO will continue to monitor activity to determine if the recent changes are related to influx of new magma or other changes to the magma system.

Mount Gareloi is monitored by a local seismic and infrasound network, satellite data, and regional infrasound and lightning-detection networks.

Lava continues to erupt slowly within the summit crater of Great Sitkin Volcano. Minor earthquakes were detected in the past day. Steaming from the summit area was observed in satellite views.  Clouds obscured webcam views of the volcano.

The current eruption began in July 2021. Since then, lava flows have 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, webcams, and regional infrasound and lightning networks.

Slightly elevated seismic and infrasound activity continues, and minor sulfur dioxide emissions were detected in satellite data over the past day. Clouds obscured webcam views, but pilots overflying the volcano yesterday reported steaming from the summit.

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 lightning data, and satellite images to detect eruptions.