As senior researcher of the Institute of Volcanology of the Russian Academy of Sciences Alexei Ozerov told RIA Novosti, the ash cloud from the strongest explosions rises to a height of 4,000-6,000 metres. The train of ash stretches for more than 70 kilometres to the north-east of the volcano towards the Pacific.
Particles of volcano ash breed serious danger to the aircraft flying along Kamchatka's eastern coast.
After the many-month "silence" the volcano's activity considerably increased last Sunday.
The viscid lava cupola is continuing to grow in the crater. Its height is already of the order of 500 metres.
Taking into consideration the explosive character of Shiveluch volcano's eruptions, the cupola can be destroyed. This breeds serious danger to the populated areas and service lines situated near the volcano's foot.
Mud flows descending from the volcano's slope repeatedly washed out the nearby motor road.
Shiveluch volcano is the northernmost of Kamchatka's active volcanos and one of the biggest with the of 3,283 metres above sea level.
Major disastrous eruptions of Shiveluch volcano take place once in 100-300 years. The latest ones were registered in 1854 and 1964. Weak and average-size eruptions occur on the volcano much more frequently.