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
27th of April 2017, 5 years ago
Rinjani Volcano Observatory has detected an increase in volcanic tremor activity at Rinjani Volcano in Lombok Island, West Nusa Tenggara province. This increase is observed in the past 3 hours. The recorded tremor amplitudes vary around 5.0-24.0 mm while the background is around 0.5-1.00 mm. However, until now, no eruption plume could be observed from the observatory. 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 not visible..View
27th of September 2016, 5 years ago
1st of August 2016, 5 years ago
Report from the National Park mentioned that volcanic activity characterized by rumbling sound with volcanic ashes were observed inside the caldera after the M5.6 earthquake about 150 km in the east direction of Rinjani volcano that taken place on 31 July 2016 23:40:01 UTC (07:40:01 WITA/Central indonesian 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. Due to fog, ash-cloud is not visible from the Rinjani Volcano Observatory (around 9 km on the northeast of Rinjani summit).View
4th of November 2015, 6 years ago
Best estimate of ash-cloud top is around 14500 FT (4400 M) above sea level. Source of height data: ground observer. Eruption with volcanic ash cloud at 0050 UTC (0850 local). Eruption and ash emission is continuing. Best estimate of ash-cloud top is around 85810 FT (26003 M) above sea level, may be higher than what can be observed clearly. Source of height data: ground observer. Ash-cloud moving to west-southwest; may be higher than what can be observed clearly..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.