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
2nd of April 2017, 4 years ago
29th of March 2017, 4 years ago
Eruption with volcanic ash cloud observed at 0058 UTC (0958 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 19272 FT (5840 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash cloud moving to north..View
16th of January 2017, 4 years ago
Eruption with ash cloud observed at 2218 UTC (0718 local). Eruption is continuing. Best estimate of ash-cloud top is around 16104 FT (4880 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. White grey ash cloud moving to east..View
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.