(1) VOLCANO OBSERVATORY NOTICE FOR AVIATION (VONA)
 (2) Issued: 20190625/00247Z
 (3) Volcano: Raikoke (CAVW #290250)
 (4) Current aviation colour code: ORANGE
 (5) Previous aviation colour code: orange
 (6) Source: KVERT
 (7) Notice Number: 2019-105
 (8) Volcano Location: N 48 deg 17 min E 153 deg 15 min
 (9) Area: Central Kuriles, Russia
(10) Summit Elevation: 1807 ft (551 m)
(11) Volcanic Activity Summary: The strong explosive eruption of the volcano lasted from 1805 UTC on 21 June till about 0800 on 22 June. According to satellite data, a gas-steam plume possibly with some amount of ash extend for 60 km to the north-west of the volcano. But a large aerosol cloud continue to drift to the west of the volcano. The edge of aerosol cloud front is located about 1700 km to the northwest (320 degrees) of the volcano. 

The explosive eruption of the volcano gradually finishing. Ash explosions up to 32,800-49,200 ft (10-15 km) a.s.l. possibly is remain. Ongoing activity could affect international and low-flying aircraft.
(12) Volcanic cloud height: 4,900-6,600 ft (1500-2000 m) AMSL Time and method of ash plume/cloud height determination: 20190624/2340Z – Satellite data, Himawari-8
(13) Other volcanic cloud information: Distance of ash plume/cloud of the volcano: 37 mi (60 km)
Direction of drift of ash plume/cloud of the volcano: 294 degrees - NW
(14) Remarks:
(15) Contacts: Olga A. Girina, IVS FEB RAS girina@kscnet.ru 

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/index_eng.php.

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, June 25, 2019. KVERT, Institute of Volcanology and Seismology FEB RAS. URL: http://www.kscnet.ru/ivs/kvert/van/?n=2019-105.
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]