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
 

22nd of August 2018, 3 years ago

2018-08-22 10:55:00 UTC Orange

Anak Krakatau - 20180822/1055Z 

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

Eruption with ash clouds at 10:47 UTC (17:47 local time). The eruption lasted for 35 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6389 FT (1936 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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2018-08-22 10:44:00 UTC Orange

Anak Krakatau - 20180822/1044Z 

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

Eruption with ash clouds at 10:35 UTC (17:35 local time). The eruption lasted for 33 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6389 FT (1936 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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17th of August 2018, 3 years ago

2018-08-17 11:59:00 UTC Orange

Anak Krakatau - 20180817/1159Z 

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

Eruption with ash clouds at 11:30 UTC (18:30 local time). The eruption lasted for 59 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 north..

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2nd of August 2018, 3 years ago

2018-08-02 09:06:00 UTC Orange

Anak Krakatau - 20180802/0906Z 

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

Eruption with ash clouds at 09:00 UTC (16:00 local time). The eruption lasted for 19 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 4277 FT (1296 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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2018-08-02 09:00:00 UTC Orange

Anak Krakatau - 20180802/0900Z 

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

Eruption with ash clouds at 08:56 UTC (15:56 local time). The eruption lasted for 19 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 4277 FT (1296 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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2018-08-02 08:59:00 UTC Orange

Anak Krakatau - 20180802/0859Z 

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

Eruption with ash clouds at 08:54 UTC (15:54 local time). The eruption lasted for 20 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 4277 FT (1296 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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2018-08-02 08:58:00 UTC Orange

Anak Krakatau - 20180802/0858Z 

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

Eruption with ash clouds at 08:51 UTC (15:51 local time). The eruption lasted for 26 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 4277 FT (1296 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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2018-08-02 08:54:00 UTC Orange

Anak Krakatau - 20180802/0854Z 

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

Eruption with ash clouds at 08:43 UTC (15:43 local time). The eruption lasted for 19 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 4277 FT (1296 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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2018-08-02 08:53:00 UTC Orange

Anak Krakatau - 20180802/0853Z 

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

Eruption with ash clouds at 08:42 UTC (15:42 local time). The eruption lasted for 13 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 north..

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2018-08-02 08:48:00 UTC Orange

Anak Krakatau - 20180802/0848Z 

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

Eruption with ash clouds at 07:54 UTC (14:54 local time). The eruption lasted for 64 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6389 FT (1936 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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2018-08-02 08:41:00 UTC Orange

Anak Krakatau - 20180802/0841Z 

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

Eruption with ash clouds at 07:00 UTC (14:00 local time). The eruption lasted for 37 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6389 FT (1936 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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2018-08-02 06:48:00 UTC Orange

Anak Krakatau - 20180802/0648Z 

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

Eruption with ash clouds at 06:33 UTC (13:33 local time). The eruption lasted for 43 seconds. Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 6389 FT (1936 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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16th of July 2018, 3 years ago

2018-07-16 12:03:00 UTC Orange

Anak Krakatau - 20180716/1203Z 

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

Eruption with ash clouds at 10:08 UTC (17:08 local time). The eruption lasted for 70 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 north..

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15th of July 2018, 3 years ago

2018-07-15 10:53:00 UTC Orange

Anak Krakatau - 20180715/1053Z 

Martanto, S.T., Anak Krakatau Volcano Observatory - 3 years ago

Eruption with volcanic ash cloud at 0022 UTC (1722 Local). Eruption and ash 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 north..

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7th of July 2018, 3 years ago

2018-07-07 01:01:00 UTC Orange

Anak Krakatau - 20180707/0101Z 

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

Eruption with volcanic ash cloud at 2259 UTC (0559 local). Eruption and ash emission is continuing. 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. Ash-cloud moving to east-northeast. Anak Krakatau volcano is not clear and not visible..

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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.