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
 

14th of November 2018, 2 years ago

2018-11-14 05:26:00 UTC Orange

Anak Krakatau - 20181114/0526Z 

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

Eruption with ash clouds at 05:05 UTC (12:05 local time). The eruption lasted for 56 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 east..

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2018-11-14 03:44:00 UTC Orange

Anak Krakatau - 20181114/0344Z 

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

Eruption with ash clouds at 03:28 UTC (10:28 local time). The eruption lasted for 50 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 14131 FT (4282 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to east..

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2018-11-14 01:51:00 UTC Orange

Anak Krakatau - 20181114/0151Z 

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

Eruption with ash clouds at 01:40 UTC (08:40 local time). The eruption lasted for 175 seconds. Eruption and ash emission is continuing. 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 moving to north..

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12th of November 2018, 2 years ago

2018-11-12 23:42:00 UTC Orange

Anak Krakatau - 20181112/2342Z 

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

Eruption with ash clouds at 23:36 UTC (06:36 local time). The eruption lasted for 44 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 east..

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2018-11-12 23:29:00 UTC Orange

Anak Krakatau - 20181112/2329Z 

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

Eruption with ash clouds at 22:49 UTC (05:49 local time). The eruption lasted for 50 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 22:54:00 UTC Orange

Anak Krakatau - 20181112/2254Z 

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

Eruption with ash clouds at 22:46 UTC (05:46 local time). The eruption lasted for 45 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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2018-11-12 10:09:00 UTC Orange

Anak Krakatau - 20181112/1009Z 

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

Eruption with ash clouds at 09:56 UTC (16:56 local time). The eruption lasted for 38 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 north..

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2018-11-12 10:05:00 UTC Orange

Anak Krakatau - 20181112/1005Z 

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

Eruption with ash clouds at 09:53 UTC (16:53 local time). The eruption lasted for 72 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 north..

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2018-11-12 10:00:00 UTC Orange

Anak Krakatau - 20181112/1000Z 

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

Eruption with ash clouds at 09:50 UTC (16:50 local time). The eruption lasted for 49 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 north..

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2018-11-12 06:29:00 UTC Orange

Anak Krakatau - 20181112/0629Z 

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

Eruption with ash clouds at 06:24 UTC (13:24 local time). The eruption lasted for 81 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 north..

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2018-11-12 04:47:00 UTC Orange

Anak Krakatau - 20181112/0447Z 

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

Eruption with ash clouds at 04:39 UTC (11:39 local time). The eruption lasted for 77 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 04:44:00 UTC Orange

Anak Krakatau - 20181112/0444Z 

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

Eruption with ash clouds at 04:35 UTC (11:35 local time). The eruption lasted for 117 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 10963 FT (3322 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 04:19:00 UTC Orange

Anak Krakatau - 20181112/0419Z 

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

Eruption with ash clouds at 04:15 UTC (11:15 local time). The eruption lasted for 114 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 10963 FT (3322 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 04:15:00 UTC Orange

Anak Krakatau - 20181112/0415Z 

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

Eruption with ash clouds at 04:08 UTC (11:08 local time). The eruption lasted for 104 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 10963 FT (3322 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 04:06:00 UTC Orange

Anak Krakatau - 20181112/0406Z 

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

Eruption with ash clouds at 03:49 UTC (10:49 local time). The eruption lasted for 78 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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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.