As early as 27 February 2010, gas plumes had erupted from Klyuchevskaya Sopka (reaching elevations of ) and during the first week of March 2010, both explosive ash eruptions and effusive lava eruptions occurred until, by 9 March, the ash cloud was reported to have reached an elevation of . Also, significant thermal anomalies have been reported and gas-steam plumes extended roughly to the north-east from the volcano on 3 March.