An ash plume from the eruption reached a height of 10 km (33,000 ft) before drifting eastward, disrupting air traffic between the United States and Asia and causing ashfalls on Alaska's Unimak Island.

[citation needed] As early as 27 February 2010, gas plumes had erupted from Klyuchevskaya Sopka, reaching elevations of 7,000 m (22,966 ft).

As well, significant thermal anomalies have been reported, and gas-steam plumes extended roughly 50 km (31 mi) to the north-east from the volcano beginning on March 3rd.

A weak thermal eruption occurred on 29 November 2012, then stopped again, as all of its neighboring volcanoes Bezymianny, Karymsky, Kizimen, Shiveluch, and Tolbachik erupted more actively and continuously, taking a major magma supply load off of Klyuchevskaya Sopka.

During January 2013, all volcanoes in the eastern part of Kamchatka—Bezymianny, Karymsky, Kizimen, Klyuchevskaya Sopka, Shiveluch, and Tolbachik—erupted, with the exception of Kamen.

[citation needed] On 15 August 2013, the volcano had another weak Strombolian eruption with some slight lava flow that put on an excellent fireworks display before stopping on 21 August 2013, when Gorely Volcano woke up and started erupting again in relief of Klyuchevskaya Sopka.

[citation needed] On 12 October, Klyuchevskaya Sopka had another three days of on-and-off eruptions with anomalies and a short ash plume, possibly indicating Strombolian and weak Vulcanian activity.

An explosion from a new cinder cone low on Kliuchevskoi's southwest flank occurred on 12 October.

[3] On 19 November, a strong explosion occurred, and observers reported that ash plumes rose to altitudes of 10–12 km (33,000–39,000 ft) and drifted southeast.

Video showed gas-and-steam activity, and satellite images detected a daily weak thermal anomaly.