(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA) (2) Issued:20231031/0234Z (3) Volcano:Klyuchevskoy (CAVW #300260) (4) Current aviation colour code:RED (5) Previous aviation colour code:orange (6) Source:KVERT (7) Notice Number:2023-137 (8) Volcano Location:N 56 deg 3 min E 160 deg 38 min (9) Area:Kamchatka, Russia (10) Summit Elevation:4750 m (15580 ft)(11) Volcanic Activity Summary:Activity of the volcano significantly increased. Satellite data by KVERT showed the ash column rose up to 9.5-9.8 km a.s.l., and is extending for 192 km to the southwest of the volcano. Probably, the ash plume containing mainly old deposits from collapses in Apakhonchichsky chute.\n\nThe summit explosive-effusive eruption of the volcano continues. Ash explosions up to 12 km (39,400 ft) a.s.l. could occur at any time. Ongoing activity could affect international and low-flying aircraft. (12) Volcanic cloud height:9500-9600 m (31160-31488 ft) AMSL Time and method of ash plume/cloud height determination: 20231031/0200Z – Himawari-9 14m15(13) Other volcanic cloud information:Distance of ash plume/cloud of the volcano: 192 km (119 mi)\nDirection of drift of ash plume/cloud of the volcano: SSW / azimuth 195 deg \nTime and method of ash plume/cloud determination: 20231031/0200Z – Himawari-9 14m15(14) Remarks:The summit explosive-effusive eruption of the volcano continues. Against the background of explosive activity of the Strombolian type (lava fountaining in the volcanic crater up to 500 m), the lava flow continue to effuse along the Apakhonchichsky chute on the southeastern slope of the volcano. (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.