Ash emissions from the ongoing eruption at Semisopochnoi volcano, Alaska have increased in frequency and intensity, prompting the Alaska Volcano Observatory (AVO) to raise the Aviation Color Code to Red at 05:58 UTC on September 20, 2021. Satellite images show an…
Eruptive activity continues at the north crater of Mount Cerberus on Semisopochnoi Island, the Alaska Volcano Observatory (AVO) reported at 20:01 UTC on September 8, 2021. Seismicity at the volcano remains elevated and variable, with periods of continuous tremor,…
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)…
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…
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…
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…
The Alaska Volcano Observatory (AVO) has raised the Aviation Color Code to Red and the Alert Level to Warning for Semisopochnoi volcano on Friday, April 16, 2021, after sustained ash emissions rose up to 6 km (20 000 feet) a.s.l. Satellite data suggest ash emissions…
Regional infrasound sensors detected a small explosion at Semisopochnoi volcano, Alaska on March 19, 2021, indicating an increase in eruptive activity. As a result, the Alaska Volcano Observatory (AVO) has raised the Aviation Color Code to ORANGE and the Volcano…
A high-resolution satellite image acquired on February 7, 2021, shows a second small ash deposit extending at least 3 km (1.8 miles) to the northeast from North Cerberus Crater on Semisopochnoi Island, similar to the first observed on February 6. Clouds obscured…
High-resolution satellite imagery acquired on February 6, 2021, showed a small ash deposit extending less than 3 km (1.8 miles) to the north from North Cerebus Crater on Semisopochnoi Island, Alaska, U.S. Steam emissions obscured views into the crater, the Alaska…
