(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) (2) Issued:20210810/2231Z (3) Volcano:Chirinkotan (CAVW #290260) (4) Current aviation colour code:ORANGE (5) Previous aviation colour code:orange (6) Source:KVERT (7) Notice Number:2021-83 (8) Volcano Location:N 48 deg 58 min E 153 deg 28 min (9) Area:Northern Kuriles, Russia (10) Summit Elevation:724 m (2374.72 ft)(11) Volcanic Activity Summary:The moderate explosive event of the volcano Chirinkotan (Chirinkotan Island) occurred at 19:55 UTC on 10 August. Ash cloud 14x11 km in size continues to drift for 70 km to the west of the volcano. \n\nThe moderate eruptive activity of the volcano continues. Ash explosions up to 10-15 km (32,800-49,200 ft) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft. (12) Volcanic cloud height:2000-2500 m (6560-8200 ft) AMSL Time and method of ash plume/cloud height determination: 20210810/2200Z – Himawari-8(13) Other volcanic cloud information:Distance of ash plume/cloud of the volcano: 70 km (43 mi)\nDirection of drift of ash plume/cloud of the volcano: W / azimuth 270 deg \nTime and method of ash plume/cloud determination: 20210810/2200Z – Himawari-8\nStart time of explosion and how determined: 20210810/1955Z – Satellite data(14) Remarks:Last moderate explosive eruption of the volcano was in 2013-2015; explosions sent ash up to 4 km a.s.l.(15) Contacts:Dr. Olga A. Girina, Head of KVERT, IVS FEB RAS\ngirina@kscnet.ru +74152202044\n\nDuty scientist: +79622825253 (16) Next Notice:A new VONA will be issued if conditions change significantly or the colour code is changed. VONAs are posted at http://www.kscnet.ru/ivs/kvert/.\n\nIn Russia, KVERT, on behalf of the Institute of Volcanology and Seismology (IVS) FEB RAS, is responsible for providing information on volcanic activity to international air navigation services for the airspace users.