Abstract:
Data on pyroclastic deposits, visual observations, and seismicity were used to reconstruct the sequence of eruptive events at Bezymyannyi in 1993. The eruption consisted of three episodes of block-and-ash pyroclastic flows which traveled for distances of 7, 8, and 5 km, respectively. The eruption column rose to a height of 13 km. The second episode of pyroclastic flows was accompanied by a partial collapse of the dome 0.006 km 3 in volume. A powerful vertical explosion and a lava flow occurred at the end of the eruption. The explosion deposited dense andesite lapilli over an area > 50 km SE of the volcano. The total volume of the erupted material was 0.07 km 3 . A brief description is given of the subsequent volcanic activity till September 1995: lava flowed episodically, no significant explosions took place.