1977-2010 Activity of Bezymianny Volcano

Abstract

Bezymianny volcano is one of the most active volcanoes of Kamchatka, Russia. Volcanic activity of Bezymianny started in October 1955 from moderate explosive eruptions, which lasted for about half a year. On March 30 the climactic eruption occurred: catastrophic directed blast and strong Plinian activity. A growth of the lava dome Novy into the explosive crater continues from 1956 till present. 39 strong explosive eruptions of this volcano occurred in 1977-2010. Ash plumes rose up to 15 km (49,200 ft.) ASL and drifted about 1,500 km mainly to the eastern and western directions from the volcano. Always as result of these explosive eruptions there were formed tephra and pyroclastic flows deposits; and an effusion of lava flows on the lava dome occurred after explosive phases of these eruptions. Pyroclastic flows deposits were accumulating in the valleys on the south-eastern flank of the volcano. The run-out of the flows deposits varied from 3-4 till 13 km. The volume of pyroclastic deposits of eruptions varied from 0.001 till 0.05 cubic km. Lava flows effused mainly on the eastern, northern and southern slopes of the lava dome. The run-out of the lava flows varied from 0.1 till 1.2 km.