An explosive eruption of Young Shiveluch Volcano occurred on September 22, 2005, discharging a pyroclastic flow about 20 km long in the Baidarnaya River valley and an ashfall in the area of the Northern cluster of volcanoes.

Close cooperation between researchers at the Alaska Volcano Observatory, USA, the Institute of Volcanic Ge-ology and Geochemistry, Far East Division, Russian Academy of Sciences, and the Kamchatkan Experimental and Methodical Seismological Department, Geophysical Service, Russian Academy of Sciences within the framework of the aviation flight safety program carried out by KVERT (the Kamchatkan Volcanic Eruption Response Team) resulted in a successful forecast of the Bezymianny eruption, all organizations concerned be-ing warned before the event. We describe the precursory phase and evolution of this explosive eruption, as well as its products. The explosive phase lasted one day, the effusive one during about a month. The eruption pro-duced a block and ash pyroclastic flow of merapi type on the volcano's slope and a viscous lava flow on the slope of its dome. The Volcanic Explosivity Index (VEI) is about 2.

Volcano Young Sheveluch is one of the most active volcanoes in Kamchatka. Since August 1980 to the present time, an extrusive dome has been growing in the crater of the volcano. Plastic lavas in the form of large ribbons were noted on the dome already in 1980–1981, the first lava flow was observed after a paroxysmal eruption on May 9, 2004. The next large block of lava started to extrude in the end of April – beginning of May 2020. By June, 11th, it rose above the dome on 50–80 m, and up to 120 m by the end of October. On September 28, it was noted that the lava block acquired smooth surfaces. Portions of lava squeezed out from inside of the volcano in August – September were plastic. By December 8, the block had collapsed. In February 2021, a new block of plastic lava began to rise from the destroyed block. In March its height above the dome exceeded 50–60 m, and 200 m in June.