The volcanic activity of Mt Ruapehu had a significant impact on civil aviation in New Zealand during 1995 and 1996. Many flights were cancelled and many more diverted or rerouted. These episodes were the first impact of volcanic ash on modern aviation in New Zealand.

A targeted volcanic ash information system was implemented following those events. CAA recognises the aviation industry's ability to manage its operations in proximity to volcanic ash with the CAA's role being one of facilitation and oversight.

In more recent years, the risks posed by volcanic gases on aircraft and on the health of its occupants have become more apparent, with work now underway within the ICAO MET Panel to develop a sulphur dioxide advisory system. Work is also underway to elevate the Volcanic Observatory Notice to Aviation (VONA) to a recommended practice in Annex 3 to the Convention. This means information on significant pre-eruptive activity and on eruptions themselves will be disseminated alongside other meteorological information. The ICAO MET Panel is also developing a quantitative volcanic ash information service, which will allow operators to make risk-based decisions on observed and forecast concentrations of volcanic ash at various levels in the atmosphere.

The Wellington Volcanic Ash Advisory Centre (VAAC), operated by MetService, provides meteorological information about volcanic ash, such as Volcanic Ash Advisories and Volcanic Ash SIGMET, the standards of which reflect New Zealand’s ICAO obligations. Information on significant pre-eruptive activity of New Zealand volcanoes is available in Volcanic Activity Bulletins provided by GNS Science, while Volcanic Alert Levels of 2 or above for New Zealand volcanoes are indicated on the Graphical NZ SIGWX chart and advised by NOTAM on changing Volcanic Hazard Zones.

The volcanic ash information system is supported through the collaborative effort of MetService, GNS Science, Airways NZ and aircraft operators.

To contact the Manager, Wellington VAAC, email

Video: Accessing and using volcanic activity information for pilots

New Zealand practices and procedures

Living with Volcanic Ash Episodes in Civil Aviation [PDF 1.3 MB]

The New Zealand Volcanic Alert Level (VAL) System [PDF 353 KB]

Volcanic Eruption – Recommended actions for airports [PDF 248 KB]


CA010 Volcanic Activity Report [PDF 144 KB]

Reference information

Taranaki Mounga volcanic ash exercise report [PDF 1.5 MB]

Quantitative Volcanic Ash Information Flyer [PDF 706 KB]

WMO Services for Aviation - Volcanic Ash Clouds and Gases(external link)

Handbook on the International Airways Volcano Watch (Doc 9776)(external link)

IFALPA video: Volcanic Ash, an Aviation Hazard of Explosive Proportions(external link)

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