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
 

23rd of May 2018, 3 years ago

2018-05-23 08:32:00 UTC Orange

Merapi - 20180523/0832Z 

Niken Angga Rukmini, S.T., Merapi Volcano Observatory - 3 years ago

Eruption at 0649 UTC (1349 local). Eruption has deceased. 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 south-west..

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22nd of May 2018, 3 years ago

2018-05-22 21:28:00 UTC Orange

Merapi - 20180522/2128Z 

Sulistiyani, S.Si., Merapi Volcano Observatory - 3 years ago

Eruption with volcanic ash cloud at 2031 UTC (0331 local). Not continuing. Best estimate of ash-cloud top is around 52463 FT (15898 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to south-west.

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2018-05-22 10:22:00 UTC Green

Merapi - 20180522/1022Z 

Agus Budi Santoso, Dr., S.Si., M.Sc., Merapi Volcano Observatory - 3 years ago

No eruption occurred after the last eruption on 21 May 2018 at 1847 UTC Best estimate of ash-cloud top is around 31607 FT (9578 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. White volcanic plume with low pressure and intensity.

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21st of May 2018, 3 years ago

2018-05-21 03:17:00 UTC Yellow

Merapi - 20180521/0317Z 

Agus Budi Santoso, Dr., S.Si., M.Sc., Merapi Volcano Observatory - 3 years ago

Eruption with volcanic ash cloud at 0238 UTC (0938 local). Not continuing. Best estimate of ash-cloud top is around 44015 FT (13338 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to west..

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11th of May 2018, 3 years ago

2018-05-11 08:01:00 UTC Yellow

Merapi - 20180511/0801Z 

Niken Angga Rukmini, S.T., Merapi Volcano Observatory - 3 years ago

Eruption and ash emission is not 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 has dissipated. .

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2018-05-11 01:40:00 UTC Red

Merapi - 20180511/0140Z 

Niken Angga Rukmini, S.T., Merapi Volcano Observatory - 3 years ago

Eruption with volcanic ash cloud at 0040 UTC (0740 local). Best estimate of ash-cloud top is around 58080 FT (17600 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving from south to east. Grey color..

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17th of February 2016, 5 years ago

2016-02-17 03:00:00 UTC Yellow

Merapi - 20160217/0300Z 

Martanto, S.T., Merapi Volcano Observatory - 5 years ago

Eruption has ceased. Volcanic activity has decreased significantly. 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 has dissipated..

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16th of February 2016, 5 years ago

2016-02-16 23:45:00 UTC Red

Merapi - 20160216/2345Z 

Martanto, S.T., Merapi Volcano Observatory - 5 years ago

Eruption with volcanic ash-cloud at 2335 UTC (0835 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 81312 FT (24640 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Large 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.