The Kamchatka department of the Geophysical Services of the Russian Academy of Sciences said that the volcano had began erupting almost two weeks ago and that more than 400 earthquakes had occurred near Klyuchevskoi (15,580 ft) over the past 24 hours. With an increase in the volcano's activity, experts forecast lava descents and mud flows, which could pose a danger to those in close vicinity to the volcano.
Scientists said the eruption was not immediately dangerous for the peninsula's settlements, but ash, which fell in the village of Klyuchi and consisted of magma particles with a diameter of up to 2 millimeters (.078 inches), could contaminate land and water. Ash emissions and trails could also present a danger to aircraft.
The eruption started February 15, when Klyuchevskoi began erupting volcanic bombs, and a pulsating glow above the giant volcano's crater indicated that fresh magma was rising to the surface.
The last time the volcano erupted was in January 2005 and lasted to May 2005, when lava flowed down its western and northern slopes. The lava temperature was some 1,100 degrees Celsius. Volcanic bombs were ejected every 10-20 seconds to a height of 700 meters. Gas and vapor emissions containing ash rose to 4 kilometers (2.5 miles).