- Ash plume from the Great Sitkin volcano eruption was as high as 15,000ft (4,600m)
- The eruption had been preceded by increased volcanic-seismic unrest over the previous 24 hours
- The volcano has had a few short-lived eruptions over the past 100 years
The US Geological Survey (USGS) issued a statement today announcing that volcanic activity on Great Sitkin Island had been confirmed by geophysical data. The volcano started erupting at 9:04pm on Tuesday, with an explosion that lasted a couple of minutes, and was continuing to erupt at the time of its latest update.
The eruption prompted the USGS and the Alaska Volcano Observatory (AVO) to issue a joint ‘red warning’ to aviation after observations suggested the ash plume from the Great Sitkin volcano eruption was as high as 15,000ft (4,600m).
“Since that explosion, seismicity has decreased, and satellite images show that the ash cloud has detached from the vent and is moving towards the east,” the Alaska Volcano Observatory said in the latest update.
A number of photos on social media, some unverified, appear to show the ash cloud suspended over the sea and a number of remote islands. One image (featured), probably taken from the community of Adak, approximately 26 miles (43km) west of the volcano, highlights the size of the discharge.
The eruption had been preceded by increased volcanic-seismic unrest over the previous 24 hours, and elevated surface temperatures and sulfur dioxide had been detected over the past week.
Great Sitkin is one of the Aleutian Islands, most of which belong to the US state of Alaska. The volcano, of which there are many among the Aleutian Islands, has had a few short-lived eruptions over the past 100 years, the latest being small steam explosions in 2019.