On December 7, activity at Kliuchevskoi significantly increased, having continued during November 29 – December 7, prompting KVERT to raise the Alert Level to Red. Ash plumes rose to altitudes of above sea level and drifted more than northeast and over east. According to a news article, a warning to aircraft was issued for the area around the volcanoes. Video showed gas-and-steam activity, and satellite images detected a daily weak thermal anomaly. On December 9, the Alert Level was lowered to Green when the eruptions abruptly stopped.