Unrest under Semisopochnoi volcano increased at the end of July, with a marked increase in seismicity on July 31. Increased activity has also been detected on local infrasound stations, suggesting possible low-level (below 3 km / 10 000 feet above sea level)…
A massive shallow earthquake registered by the USGS as M8.2 hit near the coast of Alaska at 06:15 UTC on July 29, 2021. The agency is reporting a depth of 32.2 km (20 miles). EMSC is reporting it as M8.2 at depth of 30 km (18.6 miles). This is the strongest…
A lava dome-like feature formed in the summit crater of Great Sitkin volcano, Alaska, suggesting magma is rising near the surface. As a result, the Alaska Volcano Observatory (AVO) has raised the Aviation Color Code to ORANGE and the Volcano Alert Level to WATCH. A…
The Alaska Volcano Observatory (AVO) has raised the Aviation Color Code for Semisopochnoi volcano to Orange and the Volcano Alert Level to Watch on July 12, 2021. The decision was made due to the onset of continuous volcanic tremors and detections of explosive…
A slight increase in seismic activity was observed at Gareloi volcano, Alaska on May 18, 2021, and beginning May 27 there has been a sustained increase in the rate and size of small volcanic earthquakes. Because the level of seismic activity is now above the…
A strong earthquake registered by the USGS as M6.1 hit Alaska at 06:59 UTC on May 31, 2021, at a depth of 58.2 km (36 miles). EMSC is reporting the same magnitude and depth. The epicenter was located 76.2 km (47.3 miles) N of Chickaloon (population 272), 128.3 km…
A short-lived explosive eruption began at Great Sitkin volcano, Alaska at 05:04 UTC on May 26, 2021, and lasted for about 1 to 2 minutes. The Aviation Color Code was raised to Red at 05:30 UTC. This was the first significant explosion at the volcano since 1974. The…
Several small explosions were detected at Semisopochnoi volcano, Alaska on May 18, 2021, and a small ash cloud was observed in a satellite image acquired at 23:21 UTC on May 17. As a result, the Alaska Volcano Observatory (AVO) has raised the Aviation Color Code to…
Above-background activity has been observed at the Great Sitkin volcano in Alaska, prompting the Alaska Volcano Observatory to raise the Aviation Color Code to Yellow and the Volcano Alert Level to Advisory on May 13, 2021. Elevated surface temperatures have been…
Eruptive activity at Semisopochnoi has gradually increased over the last 24 hours, the Alaska Volcano Observatory (AVO) reported at 21:48 UTC on April 22, 2021. Satellite views of the volcano show a continuous plume extending 80 km (50 miles) to the south at…
