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Caldera Advisory Group (CAG)

"To identify the risks and potential consequences of caldera unrest and eruption, and co-ordinate the management and mitigation of the effects on behalf of the communities at risk and at the national level"- CAG mission statement


Taupo caldera
 Taupo Caldera


The Waikato Regional Council is a founding member of the Caldera Advisory Group (CAG) steering committee. The CAG formed in late 2010 to provide a specific mechanism for national and local authorities, the science community and other stakeholders to share hazard information relating to the eight caldera volcanoes in the Taupo Volcanic Zone. In particular, how caldera unrest (i.e. not eruptive activity) would impact on the social and economic environments and focusing on what measures can be taken to manage these impacts.

The current members of the CAG steering committee are:

  • Bay of Plenty CDEM Group
  • Ministry of Civil Defence and Emergency Management
  • Waikato CDEM Group
  • Taupo District Council
  • Rotorua District Council
  • GNS Science
  • Waikato Regional Council
  • Bay of Plenty Regional Council
  • Earthquake Commission (EQC).


Previous unrest episodes in New Zealand and similar volcanoes overseas have resulted in months to years of earthquake swarms, metres of deformation and self-evacuations. To this end, a Caldera Advisory Group (or CAG) involving a number of key agencies has been established to progress the thinking and planning from a caldera unrest event. The Okataina and Taupo Volcanic Centres are regarded as some of the most active caldera systems in the world, and yet little has been done to prepare for the consequences of an unrest event, or a resulting low frequency but high impact eruption. Caldera unrest, consists of earthquakes, ground deformation where gas flux occurs frequently and can pose hazards which need to be adequately managed.

CAG Formation

The impetus behind the CAG formation was twofold: Firstly, the science advisory groups based on the Auckland, Central Plateau, and Taranaki volcanoes highlighted the gap in advice available for local government and other agencies dealing with the effects of caldera volcanoes. Secondly, it has been identified that caldera unrest could last for significant periods of time (years to decades) and the effect of this would have a profound impact on the social and economic environments. The initial work of the CAG is to identify the major potential impacts of caldera unrest and to address each of the areas identified. Caldera unrest is also of "national interest" given the likely impacts, multi-CDEM Group involvement and the lengthy duration of any unrest event. The BOP and Waikato CDEM Group Plans rank caldera unrest as the 4th and 3rd highest hazard respectively.

For further information on New Zealand's active volcanoes visit the GNS Science website. For the current alert level status of all the volcanoes monitored, please visit the GeoNet website.


View the Caldera unrest management in New Zealand presentation in pdf format below:

Caldera unrest management in New Zealand (1.3mb)


This is an interesting video on the research into Caldera unrest conducted by Dr Sally Potter:

Find out more about regional hazards and emergency management.




Caldera Advisory Group Members can log into their page here.