Alexei Ozerov, a leading researcher at the Russian Academy of Sciences Volcanology and Seismology Institute's Far Eastern department, said the volcano's activity has sharply increased since it last erupted February 15.
"The size of the lava globs reaches several meters in diameter," the researcher said. "We should expect lava flows to appear on the slope of the volcano anytime now."
Ozerov said such eruptions have not taken place for more than 15 years, but added that tourists and sportsmen should avoid the slopes of the volcano.
Prior to its February eruption, Klyuchevskoi last came to life in January-May 2005. Following that eruption, the volcano "sank" by 50 meters (about 165 feet), from 4,800 meters (about 16,000 feet) to the current 4,750 meters (15,845 feet).
Eruptions do not immediately threaten the Peninsula's settlements, but volcanic ash, consisting of magma particles with a diameter of up to 2 millimeters (.078 inches), can poison land and water. Ash emissions and trails can also present a danger to aircraft.
