Russia's northernmost active volcano is churning out ash to a height of over 6,000 meters (20,000 feet) in the country's Far East, local scientists reported on Saturday. The 3,283-meter (10,771-foot) Shiveluch volcano increased activity in May 2009 and has been periodically spewing ash from three to 10 kilometers. "The ashfall is accompanied by light-intensity near-surface tremors with average duration of 12 to 40 minutes," a source at the Far Eastern Institute of Volcanology and Seismology said. According to scientists, the volcanic activity over the past two-three years has significantly altered the contour of the volcano with the crater increasing in size by 50% and the slopes becoming far steeper than before. Although the current eruption poses no immediate threat to nearby settlements, the ensuing ash fallouts could be hazardous to health and the environment. The clouds of volcanic ash could also pose threat to air traffic because the tiny particles cause problems with aircraft engine turbines. The recent eruption of the Cordon Caulle volcano in Chile has grounded hundreds of flights in the southern Pacific, stranding tens of thousands of passengers. Two other active Kamchatka volcanoes - the Karymsky and the Kizimen - also currently pose a potential threat to air traffic. They both periodically spew ash and register seismic activity, although on a smaller scale compared to Shiveluch.