PETROPAVLOSVK-KAMCHATSKY, July 7 (RIA Novosti, Oksana Guseva) - A sharp increase in the activity of Mount Shiveluch, the northernmost volcano on the Kamchatka Peninsula (the Russian Far East), has been registered.

After a three-month-long eruption that produced gas and ash plumes and debris avalanches, Shiveluch has started erupting two-five kilometer ash columns, said Alexei Ozerov, a senior researcher at the Far-Eastern Volcanology and Seismology Institute.

Shiveluch is producing pyroclastic flows (avalanches of gas, ash and magma debris) with temperatures reaching about 800 degrees Celsius, and 100km ash plumes, the researcher said.

Seismic control of the volcano is currently impossible because a 20km lava flow destroyed the Shiveluch seismological station in February.

The western part of the volcano's dome collapsed during the last eruption on February 27 and Shiveluch lost 200 meters. An ash cloud spread more than 700km westward affecting the peninsula and a part of the Okhotsk Sea. In March, the volcano was less active, but the February eruption may be repeated in 2005.

Shiveluch (3,283 meters), one of Kamchatka's 28 active volcanoes, poses no threat to people but ash clouds and plumes may present difficulties to vessels and aircraft.