VONA stands for Volcano Observatory Notice for Aviation. It issues reports for changes, both increases and decreases, in volcanic activities, providing a description on the nature of the unrest or eruption, potential or current hazards as well as likely outcomes. See the following link (USGS) for further details. The Center for Volcanology and Geological Hazard Mitigation (CVGHM) under the Geological Agency of the Indonesian Ministry of Energy and Mineral Resources produced VONA's reports based on analysis of data from the agency's monitoring networks as well as from direct observations. VONA's alert levels are color-coded to indicate the different types of notifications addressing specific informative needs. The reports are disseminated via email to national and international stakeholders in the aviation sector. Other interested parties can avail of them through email subscription. All notifications are publicly available online.
USGS20th of February 2017, 5 years ago
Eruption with volcanic ash cloud at 0608 UTC (1508 local). Best estimate of ash-cloud top is around 19315 FT (5853 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to west-southwest..
ViewEruption with ash clouds at 01:41 UTC (08:41 local time). The eruption lasted for 166 seconds Best estimate of ash-cloud top is around 38650 FT (11712 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud is moving to west - South .
ViewEruption with ash clouds at 01:30 UTC (08:30 local time). The eruption lasted for 317 seconds Best estimate of ash-cloud top is around 52378 FT (15872 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud is moving to west - Southwest .
View19th of February 2017, 5 years ago
Anak Krakatau - 20170219/1247Z
Strombolian eruption occurred at 1204 UTC (1904 local time). Incandescent ejected material reached 200 m in high. Best estimate of ash-cloud top is around 0 FT (0 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. No ash-cloud observed.
View18th of February 2017, 5 years ago
Eruption with ash clouds at 10:18 UTC (17:58 local time). The eruption lasted for 399 seconds Best estimate of ash-cloud top is around 57658 FT (17472 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud is moving to west..
View17th of February 2017, 5 years ago
Eruption with volcanic ash cloud observed at 2250 UTC (0750 local). Best estimate of ash-cloud top is around 22483 FT (6813 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to west-northwest..
ViewEruption with ash clouds at 15:58 UTC (22:58 local time). The eruption lasted for 287 seconds Best estimate of ash-cloud top is around 36538 FT (11072 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud is moving to west.
ViewEruption with ash clouds at 15:58 UTC (22:58 local time). The eruption lasted for 287 seconds Best estimate of ash-cloud top is around 36538 FT (11072 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud is moving to west.
View16th of February 2017, 5 years ago
Eruption with volcanic ash cloud observed at 2147 UTC (0647 local). Best estimate of ash-cloud top is around 21427 FT (6493 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. White-grey ash cloud moving to north and east..
View15th of February 2017, 5 years ago
Eruption produced dark grey ash cloud observed at 2230 UTC (0730 local). Best estimate of ash-cloud top is around 23539 FT (7133 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to west-southwest..
ViewEruption with volcanic ash cloud at 1249 UTC (1949 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 47098 FT (14272 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to west - southwest..
View14th of February 2017, 5 years ago
Eruption with ash clouds at 02:30 UTC (09:30 local time). The eruption lasted for 64 seconds Best estimate of ash-cloud top is around 34426 FT (10432 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to west-southwest..
View12th of February 2017, 5 years ago
Eruption with volcanic ash cloud at 1924 UTC (0224 local). The eruption lasted for 290 seconds Best estimate of ash-cloud top is around 36538 FT (11072 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to west-southwest..
ViewEruption with ash clouds at 00:13 UTC (07:13 local time). The eruption lasted for 290 seconds Best estimate of ash-cloud top is around 44986 FT (13632 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud is moving to west-northwest.
View11th of February 2017, 5 years ago
Eruption with ash clouds at 11:35 UTC (18:35 local time). The eruption lasted for 183 seconds Best estimate of ash-cloud top is around 44986 FT (13632 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to west-southwest..
ViewVolcano 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.
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.
Volcano is exhibiting heightened unrest with increased likelihood of eruption with column height below 6000 meter above sea level.
Eruption is forecast to be imminent with significant emission of ash with column height above 6000 meter above sea level.
