The two active volcanoes Kliuchevskoi (Klyuchevskaya Sopka) and Bezymianny and the inactive volcanoes Kamen and Ushkovsky form a concentrated group of stratovolcanoes. The highest of these volcanoes is the Kliuchevskoi at 4,835 metres.
The volcano was created a good 6,000 years ago in the direct vicinity of the volcano Kamen. The Kliuchevskoi is connected to this volcano by a saddle.
Numerous secondary craters formed along a fault system. More than 100 eruptions are known from the last 3,000 years.
In the last few centuries, the activity has concentrated increasingly on the summit crater. It has a diameter of 700 metres. One of the most recent major eruptions took place in 1994. The eruption cloud rose to a height of 20 km.
The most recent eruptions of Kliuchevskoi
In February/March 2010 there was an eruption of the volcano. First a high rising ash cloud was produced, then the volcano was strombolian active for several weeks. A lava flow was also created. Kliuchevskoi has been seismically active since June 2012 and strombolian eruptions began at the summit crater on 14 October.A new eruptive phase occurred between August and October 2013. It began with strombolian eruptions. Later several lava flows were produced. In mid-October the explosiveness of the eruption increased. Lava fountains rose up to 1000 m high and an ash cloud was produced. I was able to document this part of the eruption on site.
The most recent eruption phase started in mid April 2016. Again strombolian eruptions and lava flows manifested themselves at the beginning. When these began to push, pyroclastic flows probably started. Later, explosive ash eruptions got into the process.