VONA
What is VONA?

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.

USGS
 

12th of November 2018, 2 years ago

2018-11-12 03:58:00 UTC Orange

Anak Krakatau - 20181112/0358Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 03:43 UTC (10:43 local time). The eruption lasted for 58 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 8851 FT (2682 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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2018-11-12 03:41:00 UTC Orange

Anak Krakatau - 20181112/0341Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 03:29 UTC (10:29 local time). The eruption lasted for 54 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6739 FT (2042 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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10th of November 2018, 2 years ago

2018-11-10 08:15:00 UTC Orange

Anak Krakatau - 20181110/0815Z 

Jumono, Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 05:54 UTC (12:54 local time). The eruption lasted for 103 seconds. Best estimate of ash-cloud top is around 12019 FT (3642 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud is moving to north..

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9th of November 2018, 2 years ago

2018-11-09 10:15:00 UTC Orange

Anak Krakatau - 20181109/1015Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 10:17 UTC (17:10 local time). The eruption lasted for 51 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6739 FT (2042 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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2018-11-09 09:38:00 UTC Orange

Anak Krakatau - 20181109/0938Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 09:32 UTC (16:32 local time). The eruption lasted for 51 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 7795 FT (2362 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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2018-11-09 09:30:00 UTC Orange

Anak Krakatau - 20181109/0930Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 09:26 UTC (16:26 local time). The eruption lasted for 55 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6739 FT (2042 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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2018-11-09 09:26:00 UTC Orange

Anak Krakatau - 20181109/0926Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 09:20 UTC (16:20 local time). The eruption lasted for 42 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 8851 FT (2682 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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6th of November 2018, 2 years ago

2018-11-06 03:09:00 UTC Orange

Anak Krakatau - 20181106/0309Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 03:00 UTC (10:00 local time). The eruption lasted for 54 seconds. Best estimate of ash-cloud top is around 9907 FT (3002 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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2018-11-06 02:42:00 UTC Orange

Anak Krakatau - 20181106/0242Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 09:23 UTC (02:23 local time). The eruption lasted for 37 seconds. Best estimate of ash-cloud top is around 8851 FT (2682 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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2018-11-06 02:37:00 UTC Orange

Anak Krakatau - 20181106/0237Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 2 years ago

Eruption with ash clouds at 09:09 UTC (02:09 local time). The eruption lasted for 29 seconds. Best estimate of ash-cloud top is around 8851 FT (2682 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to north..

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21st of September 2018, 3 years ago

2018-09-21 22:56:00 UTC Orange

Anak Krakatau - 20180921/2256Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 3 years ago

Eruption with ash clouds at 22:48 UTC (05:48 local time). The eruption lasted for 115 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 5683 FT (1722 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to south..

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2018-09-21 22:53:00 UTC Orange

Anak Krakatau - 20180921/2253Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 3 years ago

Eruption with ash clouds at 22:41 UTC (05:41 local time). The eruption lasted for 108 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6739 FT (2042 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to south..

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2018-09-21 09:00:00 UTC Orange

Anak Krakatau - 20180921/0900Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 3 years ago

Eruption with ash clouds at 08:27 UTC (15:27 local time). The eruption lasted for 85 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 5333 FT (1616 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to south..

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2018-09-21 03:29:00 UTC Orange

Anak Krakatau - 20180921/0329Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 3 years ago

Eruption with ash clouds at 02:21 UTC (09:21 local time). The eruption lasted for 72 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 8501 FT (2576 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to south..

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23rd of August 2018, 3 years ago

2018-08-23 17:00:00 UTC Orange

Anak Krakatau - 20180823/1700Z 

Deny Mardiono, A.Md., Anak Krakatau Volcano Observatory - 3 years ago

Eruption with ash clouds at 11:07 UTC (18:07 local time). The eruption lasted for 31 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 10613 FT (3216 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to northeast..

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VONA Color Code

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.


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.