Although the 3,283-meter (10,771-foot) Shiveluch volcano is not fully erupting, the active volcano in Kamchatka Krai has been active since May 2009 and periodically spews ash up to eight kilometers (4.9 miles) high.

But activity at the volcano has increased in recent days, and Russia’s geophysical service said on Tuesday that the volcano is now spewing plumes of ash up to a height of nine kilometers (5.6 miles). Fears are that the volcano is now at risk of a full eruption.

Because volcanic ash can pose a threat to planes and because of the increased risk of a full eruption, authorities have decided to reroute all air traffic around the ash clouds, which is close to a major air corridor for aircraft flying between Russia and locations in Japan and South Korea.

Shiveluch, one of the largest and most active volcanoes in Russia, is located in Kamchatka Krai, a federal subject of Russia. It is one of more than 150 volcanoes in Kamchatka, although only 29 of them are active.

Earlier this month, European airlines were forced to cancel nearly 1,000 flights over a span of several days after the Grimsvotn in Iceland erupted, spreading an ash cloud over several countries. So far, no flights have been canceled as a result of the volcano in Russia. Source