CALDERAConnections Among Life, geo-Dynamics and Eruptions in a Rifting Arc caldera

We propose a research project to explore the inner workings of the Okataina Volcanic Centre in the central North Island.


Caldera volcanoes produce Earth’s largest explosive eruptions but also multiple smaller eruptions that can still have major effects on communities. Under the surface of calderas, cold and hot water circulate vigorously, and researchers suspect there is plenty of life in the form of microbes

Calderas have long been studied from the surface. Scientific drilling, with extensive data collection, is needed to recover geological records of small old eruptions missing from the surface, observe water circulations and discover the underground life.

We propose the idea of a scientific drilling programme at the Okataina Volcanic centre because it is an ideal place to explore the multi-faceted inner workings of calderas. It is an active system that has been studied from the surface for a long time. Volcanic and earthquake activity is being monitored by GeoNET. A varied biosphere has already been mapped in surface hot springs.

This programme aims to…

  • identify how caldera volcanoes and the nearby tectonic plates evolve through time
  • identify what affects circulations of cold groundwater and hot geothermal or magmatic fluids
  • discover the conditions that can support underground life
  • improve monitoring of the volcano, to help understand what causes big and small eruptions and their impacts on land and communities

To achieve these objectives we...

  • are developing a scientific programme for one or two drillholes – results will provide key knowledge outcomes to local communities and advance international research on calderas
  • will conduct surveys from surface before, during and after drilling so the drillholes become underground laboratories and monitoring stations
  • will conduct multiple outreach and education activities

The project

CALDERA is a project currently being designed to explore how active calderas work using scientific drilling. Extensive data collection and multi-faceted research will spur significant scientific discoveries to improve understanding of calderas.

These discoveries will underpin

  1. resilience to volcanic and earthquake hazards;
  2. sustainable management of groundwater and geothermal resources,
  3. understanding of subsurface microbial diversity, function and geobiological interactions. There will be significant education and outreach events, at the OVC and globally.

Caldera volcanoes produce Earth’s largest explosive volcanic eruptions. These rare events create large ground depressions. In-between these rare large events, the calderas experience smaller eruptions, earthquakes (“Rocks”), but also host geothermal and groundwater resources (“Fluids”) and a largely unexplored underground life (“Life”).

In a caldera, Rocks, Fluids and Life are inter-connected

The rifting apart of tectonic plates in a rift makes space for magma to come closer to the surface. The rain naturally permeates the ground, and some of it gets heated up by the magma then migrates towards the surface. The hot water may reach the surface at hot springs, or stay trapped underground with the potential for renewable geothermal energy use. Multiple types of microbial life forms have been found in surface hot springs, and it is very likely there are some underground. The microbe’s types and their activity depend on the nearby rocks and fluids that bring nutrients.

Active calderas are found at major plate boundaries. The Okataina Volcanic Centre (OVC) is one of two giant active calderas in the Taupō Volcanic Zone, Aotearoa New Zealand, where the Taupō Rift stretches the tectonic plate. The OVC is ideal for scientific drilling and as a testbed for novel volcano monitoring approaches.

Cecile Massiot Geothermal Geoscientist

Cécile is a structural geologist and borehole log interpretation specialist who aims to unravel characteristics of fracture systems which conduct fluid flow in the Earth's crust. Her structural and geomechanical analyses in geothermal, hydrocarbon and active fault systems improve resource management and understanding of tectonics. She complements borehole data with outcrop, completion well test data and 3D-modeling studies and thrives in cross-disciplinary projects. Cécile has been involved in most borehole image log interpretations in New Zealand geothermal fields since the first deployment of ALT high temperature ABI tool in 2009. She has also interpreted borehole data in three scientific drilling programs: Iceland Deep Drilling Program (Iceland, 2009); Deep Fault Drilling Program (Alpine Fault, South Island of New Zealand, 2014); and IODP Exp. 376 Brothers Arc Flux (Kermadec arc offshore New Zealand, 2018).

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Research Project Details

Collaborators: This project is in design phase with scientists at GNS Science, and universities in New Zealand and internationally; local communities, especially iwi/hapū; regulatory and emergency management experts. Preliminary and workshop proposals have been submitted to the International Continental Scientific Drilling Program, an international research consortium that New Zealand is part of. 




Cécile Massiot


in future: ICDP, NZ and other research