(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
 (2) Issued:20250429/2237Z
 (3) Volcano:Bezymianny (CAVW #300250)
 (4) Current aviation colour code:YELLOW
 (5) Previous aviation colour code:orange
 (6) Source:KVERT
 (7) Notice Number:2025-26
 (8) Volcano Location:N 55 deg 58 min E 160 deg 35 min
 (9) Area:Kamchatka, Russia
(10) Summit Elevation:2882 m (9452.96 ft)
(11) Volcanic Activity Summary:After the explosive eruption on 23 April, an effusive eruption of the volcano continues (viscous lava is extruding onto the dome slopes), which accompanied sometimes by small hot avalanches and powerful gas-steam activity; a bright thermal anomaly over the volcano is noting on satellite images. According to KVERT satellite data, the explosive eruption of the volcano began at 23:10 UTC on 23 April, with ash being carried up to 11 km a.s.l. and pyroclastic flow deposits being formed in the Vostochnaya and Yuzhnaya Valleys. The eruptive cloud moved to the southwest and later southeast for 900 km of the volcano on 23-25 April. KVERT continues to monitor the Bezymianny volcano.

The effusive eruption of the volcano continues. Ongoing activity could affect low-flying aircraft.
(12) Volcanic cloud height:NO ASH CLOUD PRODUSED
(13) Other volcanic cloud information:NO ASH CLOUD PRODUSED
(14) Remarks:
(15) Contacts:Dr. Olga A. Girina, Head of KVERT, IVS FEB RAS
girina@kscnet.ru +74152202044

Duty 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/.

In 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.

CITATION GUIDELINES

For formal scientific citation of this VONA/KVERT Information Release, please use the following:
VONA/KVERT Information Release, April 29, 2025. KVERT, Institute of Volcanology and Seismology FEB RAS. URL: http://kvert.febras.net/van/?n=2025-26.
Aviation Colour Codes

GREEN

Volcano is in normal, non-eruptive state

   or, after a change from a higher level:

Volcanic activity considered to have ceased, and volcano reverted to its normal, non-eruptive state.

YELLOW

Volcano is experiencing signs of elevated unrest above known background levels.    

 or, after a change from higher level:

Volcanic activity has decreased significantly but continues to be closely monitored for possible renewed increase.

ORANGE

Volcano is exhibiting heightened unrest with increased likelihood of eruption.

   or,

Volcanic eruption is underway with no or minor ash emission.
[specify ash-plume height if possible]

RED

Eruption is forecast to be imminent with significant emission of ash into the atmosphere likely.

  or,

Eruption is underway with significant emission of ash into the atmosphere.
[specify ash-plume height if possible]