After an increase in seismicity from 18 November, a thermal anomaly has been observed at Bezymianny since 5 December; The temperature of this thermal anomaly increased significantly on December 13 ... a probable extrusion of lava blocks at the top of the dome would likely prepare an explosive eruption of the volcano.
The aviation code changed to orange.
Extrusion of lava at the top of the Bezymianny dome - photo April 2006 Yu. Demyanchuk, IVS FEB RAS, KVERT
Considered extinct after a millennium of dormancy, the Bezymianny began an eruption in 1955 which resulted in the emission of more than 3 km³ of eruptive products.
A lava dome began to build up in the crater immediately after the collapse of the summit, and continues its growth, accompanied by intermittent explosive activity and pyroclastic flows. It largely filled the crater of 1956. Between 1965 and 2012, 44 strong Vulcanian explosions took place.
In the Kuril Archipelago, according to Severo-Kurilsk observers, emissions of gases and vapors, containing small amounts of ash, rising up to 1,500 meters, were produced by the Ebeko volcano on 9 December. A thermal anomaly is confirmed by the satellite data. Photos on the KVERT website on 9 and 10 December confirm these emissions.
The Institute of Volcanology and Seismology of Lejano East / Russian Academy of Sciences indicates the presence of an ash plume rising to 250 meters on 13 December at 16:55 local time, and the presence of a layer of 2 mm. of ashes at six kilometers from the Ebeko. The aviation code is yellow.
Sources: KVERT & Sputnik news