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
 

10th of October 2018, 1 year ago

2018-10-10 10:26:00 UTC Yellow

Gamalama - 20181010/1026Z 

Dr. Nia Haerani, S.T., M.T., Gamalama Volcano Observatory - 1 year ago

Gas emission observed at 0852 UTC (1752 local). No sign of volcanic ash. Best estimate of ash-cloud top is around 5520 FT (1725 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Gas emitted continuously, mostly contain water vapour..

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4th of October 2018, 1 year ago

2018-10-04 03:31:00 UTC Orange

Gamalama - 20181004/0331Z 

Dr. Nia Haerani, S.T., M.T., Gamalama Volcano Observatory - 1 year ago

Eruption with volcanic ash cloud at 0252 UTC (1152 local). Best estimate of ash-cloud top is around 6288 FT (1965 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to Northwest..

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1st of July 2017, 3 years ago

2017-07-01 03:37:00 UTC Yellow

Gamalama - 20170701/0337Z 

Dr. Nia Haerani, S.T., M.T., Gamalama Volcano Observatory - 3 years ago

Increase on seismic activity detected during June 30, 1500 UTC till July 1, 0130 UTC, and ongoing till reported time. 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 sign of volcanic ash is observed at the surface..

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26th of June 2017, 3 years ago

2017-06-26 13:42:00 UTC Yellow

Gamalama - 20170626/1342Z 

Dr. Nia Haerani, S.T., M.T., Gamalama Volcano Observatory - 3 years ago

Increase on volcanic activity during the day till 1232 UTC (2132 local). No eruption or ash emission detected yet. 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 eruption nor ash emission observed..

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12th of April 2017, 3 years ago

2017-04-12 12:51:00 UTC Yellow

Gamalama - 20170412/1251Z 

Dr. Nia Haerani, S.T., M.T., Gamalama Volcano Observatory - 3 years ago

Sudden increase of Deep Volcanic earthquake since 0927 UTC (1827 local). Visual observation does not show any sign of eruption. 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 eruption observed..

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4th of January 2017, 3 years ago

2017-01-04 09:23:00 UTC Yellow

Gamalama - 20170104/0923Z 

Dr. Devy Kamil Syahbana, S.Si., Gamalama Volcano Observatory - 3 years ago

Slight increase in seismicity is observed at Gamalama volcano, Ternate, North Maluku province. There is no indication that an eruption is imminent or certain, however the chance of an eruption increases. Gamalama Volcano Observatory will continue to monitor the volcano closely. 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. Nill.

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9th of December 2016, 3 years ago

2016-12-09 23:46:00 UTC Yellow

Gamalama - 20161209/2346Z 

Dr. Nia Haerani, S.T., M.T., Gamalama Volcano Observatory - 3 years ago

Possible eruption due to increase of seismicity. No eruption observed yet. 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 emission nor ash cloud observed..

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3rd of August 2016, 3 years ago

2016-08-03 21:37:00 UTC Orange

Gamalama - 20160803/2137Z 

Martanto, S.T., Gamalama Volcano Observatory - 3 years ago

Eruption with ash cloud observed at 2119 UTC (0619 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 20750 FT (6288 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to east - southeast with grey ash colored..

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2016-08-03 07:34:00 UTC Orange

Gamalama - 20160803/0734Z 

Martanto, S.T., Gamalama Volcano Observatory - 3 years ago

Eruption with ash cloud observed at 0734 UTC (1634 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 26558 FT (8048 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to east - southeast with grey ash colored..

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2016-08-03 07:18:00 UTC Orange

Gamalama - 20160803/0718Z 

Martanto, S.T., Gamalama Volcano Observatory - 3 years ago

Eruption with ash cloud observed at 0711 UTC (1611 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 25502 FT (7728 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to east - southeast..

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2016-08-03 00:18:00 UTC Orange

Gamalama - 20160803/0018Z 

Martanto, S.T., Gamalama Volcano Observatory - 3 years ago

Eruption with ash cloud observed at 1808 UTC (0908 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 28670 FT (8688 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to east - southeast..

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2016-08-03 00:18:00 UTC Orange

Gamalama - 20160803/0018Z 

Martanto, S.T., Gamalama Volcano Observatory - 3 years ago

Ash emission from the east rupture of Gamalama at 09.09 WIT (00.09 UTC). Ash emission still continuing. Best estimate of ash-cloud top is around 28670 FT (8688 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to the east - southeast. Ash observed with dark grey colored..

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2nd of August 2016, 3 years ago

2016-08-02 22:21:00 UTC Orange

Gamalama - 20160802/2221Z 

Martanto, S.T., Gamalama Volcano Observatory - 3 years ago

Ash emission from the east rupture of Gamalama at 06.28 WIT (21.28 UTC). Ash emission still continuing and decreasing. Best estimate of ash-cloud top is around 24446 FT (7408 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ah cloud moving to the east - southeast. Greyish colored..

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1st of May 2016, 4 years ago

2016-05-01 10:51:00 UTC Yellow

Gamalama - 20160501/1051Z 

Martanto, S.T., Gamalama Volcano Observatory - 4 years ago

Gamalama Volcano Observatory has detected a slight increase in volcanic tremor activity at Gamalama Volcano on Ternate Island in the North Maluku province. This increase is observed at least since 1 May 2016 00:30 UTC (09:30 local time). The recorded tremor amplitudes vary around 0.5-4.0 mm while the background is around 0.5-1.00mm. Therefore, the Aviation Color Code is set to YELLOW. There is no indication that an eruption is imminent or certain, although the potential for an eruption has increased. Gamalama Volcano Observatory will continue to monitor the volcano closely. 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. NILL.

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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.