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Principal Scientists

GNS Science has a proud tradition of scientific excellence and internationally recognised research. Leading the way are our principal scientists who have substantial and enduring reputations in their fields. They demonstrate high productivity and outstanding achievement in science innovation and original thinking. They are recognised by their peers and by non-research entities as pre-eminent. Our principal scientists attract valuable collaborations and business opportunities and represent New Zealand with distinction on the international stage.

Stephen Bannister
Stephen is a seismologist with a research focus on imaging Earth’s structure using seismic waves from earthquakes. His work has included investigations of the Alpine Fault, and the deep structure beneath Transantarctic Mountains, and the Terror rift in Antarctica.
Currently   he is investigating the deep heat source beneath New Zealand’s geothermal fields, and characterising the seismic signature of earthquakes and tremor associated with the Hikurangi subduction megathrust. He currently leads the GNS Science research programme on Understanding Earthquakes and Tsunami.


Rafael Benites
Rafael is a geophysicist who specialises in numerical modelling of seismic wave propagation and earthquake fault ruptures. One of his main projects is to combine numerical techniques and observed earthquake data to predict strong ground motion in the Wellington metropolitan region in the event of a large earthquake on the Wellington Fault. Rafael's work on different subjects of wave propagation has led to numerous collaborations with international colleagues. In 1998 he won a Japanese Fellowship for the Promotion of Science, and in 2003 he worked as a consultant in the Bullard Laboratory, University of Cambridge, England. In 2005 he was an invited speaker at the Department of Geophysics of Beijing University, China, and in 2008 at the Earthquake Research Institute, Tokyo University, Japan.

Kelvin Berryman

Kelvin Berryman
Kelvin is a geologist by training specialising in the geology of earthquakes, tsunami, the Alpine Fault and the Hikurangi subduction margin. He often interacts with engineers, planners, and policy makers on the design of new structures, seismic safety assessment of infrastructure and disaster risk management. His research and applied science has been undertaken throughout New Zealand and extensively around the Pacific. He currently serves as NZ representative on the Governing Board of the GEM (global earthquake model) Foundation, is an associate editor of the Bulletin of the Seismological Society of America, an elected Fellow of the NZ National Society for Earthquake Engineering, and has received the two principal awards of the NZ Geosciences Society. In 2012 he received a Queens Service Order for services to science and Canterbury earthquake recovery.

Greg Browne

Greg Browne
Greg is a sedimentologist with special interests in process sedimentology, sequence stratigraphy and reservoir characterisation of both deep-water and non-marine successions.  His work has included a range of research and applied projects throughout Zealandia, particularly in Taranaki and Canterbury basins, but also in Canada, Australia, South Korea and Antarctica. He has held various research leadership roles at GNS Science including his current position as the petroleum basin research programme leader, and as a former Head of Department. Greg is an Adjunct Professor at the University of Canterbury and an Honorary Research Associate at Victoria University of Wellington.

Simon Cox
Simon is a structural geologist with professional expertise in the fields of geological mapping, tectonics, GIS modelling, fluid-flow and mineralisation, but claims he is a 'non-specialist' geoscientist. The geological mapping of the Southern Alps and southern Victoria Land, Antarctica, are among his most significant contributions. Simon has also run experiments on Southern Alps hot springs and characterised the effects of earthquakes on groundwater. One area of this research has examined the hypothesis that leakage of pressured groundwater from aquifers beneath Christchurch exacerbated liquefaction brought to the surface. Based in the Dunedin office, he is presently leading an international collaboration to build a geological dataset of Antarctica, runs the National Characterisation of Aquifers project, is working on impact of sea level rise on groundwater and landslide runout. Simon is widely recognised as a public speaker and communicator of science, maintains close ties with local iwi/māori, supervises research students, and is a recipient of the McKay Hammer Award from the New Zealand Geoscience Society.


James Crampton
James works half time at GNS and half time at Victoria University of Wellington. He is a paleontologist with expertise in the quantitative analysis of paleontological data for both applied and blue skies research. Recent paleobiological research has focussed on the relationships between climate, environmental change and biodiversity, using examples from various groups of marine plankton – plants and animals that float in the ocean - and New Zealand’s rich fossil record of shellfish. James has also worked extensively in the areas of high resolution quantitative biostratigraphic correlation, geological time scale development, the numerical description of biological form, and the Cretaceous stratigraphy, biostratigraphy and history of New Zealand. He is currently collaborating with several overseas scientists on a range of projects, is a member of several international advisory and editorial boards, an editor of the journal Paleobiology, a fellow of the Paleontological Society, and a recipient of the McKay Hammer Award from the Geological Society of New Zealand.


Cornel de Ronde
Since 1997 Cornel, a geologist, has led a sustained GNS Science programme to discover and understand submarine volcanism and hydrothermal venting along the Kermadec section of the Pacific Ring of Fire northeast of New Zealand. This frontier research includes exploring active submarine volcanoes and their seafloor hot springs using surface ships, remotely operated vehicles, autonomous underwater vehicles, and manned submersibles. Cornel has successfully brought together diverse groups of highly skilled specialists from many organisations and numerous countries to study the 2500km stretch of volcanic arc between New Zealand and Samoa. He is internationally recognised for this work and is in high demand as a speaker at a wide variety of forums from scientific conferences to special interest groups and schools. He is President-elect of the International Marine Minerals Society.

Susan Ellis
Susan specialises in geodynamic modelling of crustal deformation, from short (human) to long (millions of years) timescales. Her work has involved development of innovative numerical methods to investigate the influence of faulting on stresses and earth deformation in New Zealand. She has participated in fieldwork and numerical modelling of continental rift mechanics in Papua New Guinea; fluid and magma generation and flow in the Taupo Volcanic Zone; and brittle-ductile deformation in the Southern Alps. Recently she has led a Marsden-funded research programme studying the mechanics of New Zealand’s Hikurangi subduction margin.  Susan is a past president of the New Zealand Geophysics Society (now part of the New Zealand Geoscience Society) and has been a participant in 6 Marsden projects since 2004. She has also convened several scientific meetings including an international NSF-funded GeoPrisms workshop studying New Zealand tectonics.

Matt Gerstgenberger

Matt Gerstenberger 
Matt is a seismologist who focuses on earthquake forecasting and seismic hazard modelling. He has particular interests in better understanding and quantification of uncertainties, developing testable models (and testing them), and also developing methods for propagating uncertainties through to end uses of forecasting and hazard models. He has actively worked in seismology in the USA, Japan, Europe and Australia. He currently leads the National Seismic Hazard Model and also the earthquake forecasting teams at GNS. He is a GeoNet earthquake duty seismologist and is an Associate Editor for the Bulletin of the Seismological Society of America.

Stuart Henrys

Stuart Henrys
Stuart Henrys – Theme Leader Land and Marine Science
Stuart studies how tectonic plates collide and break apart. He uses seismology methods to provide detailed images of the earth’s crust and integrates these with a wide range of other geophysical and geological observations. The results are used to promote collaboration across the earth science community and include contributions to subduction zone structure, exploration of natural resources, and interpreting paleo-climate rock records. Stuart gained his PhD from Auckland University in 1987 and has held research positions at Rice University, Houston, and Victoria University of Wellington before joining GNS in 1994. Stuart has been a member of the International Ocean Discovery Program (IODP) Science Evaluation Panel and the Australian-New Zealand IODP Science Committee and is also the current Chair of the New Zealand IODP Committee. Stuart was a Visiting Professor at Tokyo University in 2012. He is a member of the Geoscience Society of New Zealand, American Geophysical Union, and the Society of Exploration Geophysics.

Chris Hollis

Chris Hollis
Chris Hollis is a micropaleontologist and paleoclimatologist with a particular interest in southern Pacific climate variation during the greenhouse world of the Paleogene. He has been the principal investigator on three Marsden Fund projects and was awarded the McKay Hammer by the Geological Society of New Zealand in 2005 for his Marsden team's research on the mass extinction that wiped out the dinosaurs at the Cretaceous-Paleogene boundary. Chris has been programme leader of the Global Change Through Time programme, Paleontology Department Head and Chair of the New Zealand IODP Committee. He has played a leading role in the development and delivery of several outreach and community engagement initiatives, notably Te Kura Whenua.

John Vedamuthu Kennedy

John Kennedy
John is an ion beam physicist who works on new materials development and ion beam analysis for advanced materials, biology, geology and environmental applications. He is currently investigating metal and metal oxide nanoparticle growth and their structural, electrical, optical and magnetic properties. His team is working on developing a proof-of-concept sensor devices. John leads the GNS Science core science programme of ion beam applications which focuses on research and development of ion beam technology for industry and environment sectors. He is a Principal Investigator in the high technology industry focused Materials Accelerator at University of Auckland. He is also an Associate Investigator in the MacDiarmid Institute and Research Associate at Victoria University of Wellington and The University of Auckland. John is a New Zealand representative in the international Marine pollution projects in Asia coordinated by the International Atomic Energy Agency

Nick Mortimer

Nick Mortimer
Nick is a Dunedin-based petrologist who uses the composition and texture of rocks to help answer a variety of geological, tectonic and forensic questions. He has worked in the U.S., Canada, Australia, Antarctica, all over New Zealand and in several offshore SW Pacific areas. Nick is best known for his work to define and refine the extent of Zealandia, and understand how and why it came to be Earth’s most submerged and smallest continent. This work continues. He was Senior Editor of the New Zealand Journal of Geology and Geophysics for six years, is a former Curator of GNS Science’s National Petrology Rock Collection and Petlab database, and a past-President of the Geoscience Society of New Zealand. In 2017, Nick was made a Fellow of the Royal Society of New Zealand.


Martin Reyners
Martin is a seismologist who focuses on the seismicity, structure and tectonics of the plate boundary through New Zealand. His particular interest is the country’s two subduction zones, which he has studied in detail with dense deployments of portable seismographs. A major motivation for this work has been to determine the seismic hazard posed by the shallow part of the plate interface. He has also increased understanding of recent large earthquakes through detailed aftershock studies. Martin’s work has led to substantial international collaboration, and has been recognised with a New Zealand Science and Technology Medal, the New Zealand Geophysics Prize (three times), and Fellowship of the Royal Society of New Zealand.


David Rhoades
David is a geophysical statistician who works on improving models for earthquake hazard and risk, to provide better information on the likelihood of future large earthquakes and their damaging effects, and to increase our understanding of how earthquakes are generated and what make us vulnerable to them. His pioneering collaborative studies on patterns in the occurrence of small earthquakes before big ones, are leading the way internationally in developing testable methods for long-range earthquake forecasting. He is an active participant in the California-led Collaboratory for the Study of Earthquake Predictability and is co-chair of the Working Group on Earthquake Predictability of the International Association for Seismology and Physics of the Earth's Interior.

Richard Sykes

Richard is a petroleum geochemist who studies organic-rich rocks and petroleum fluids to help exploration companies to find and produce oil and gas resources for New Zealand. Whilst New Zealand still needs oil and gas (for transportation, electricity generation, and methanol production, etc.), it is far better we produce our own rather than be entirely dependent on imports. In 2004, Richard discovered that New Zealand crude oils are derived mostly from fossil leaf cuticle in coal seams, helping to dispel the widely held theory that coals expel only gas. His current research interests involve using the geochemical fingerprints of oils to identify genetic oil families and determine oil maturity, information which helps to reveal the petroleum “plumbing systems” in the subsurface. He is also interested in the use of multivariate statistical analysis to apportion contributions in comingled well streams from different reservoir zones and fields, for improved field management. Richard is the leader of the Petroleum Source Rocks, Fluids, and Plumbing Systems research programme funded by MBIE. He has been a visiting scientist at the Geological Survey of Canada and the GeoForschungsZentrum (Germany) and regularly presents seminars and short-courses at international conferences and directly to exploration companies.

Laura Wallace

Laura Wallace
Laura Wallace is a geodetic scientist specializing in crustal deformation studies at active tectonic plate boundaries, with a focus on New Zealand, Japan, Papua New Guinea, and other regions of the western Pacific. She has worked on all types of plate boundaries, but has a particular interest in subduction plate boundary processes, including interseismic coupling and slow slip events. She primarily uses Global Positioning System (GPS) data in her research, but has more recently made the foray into seafloor geodesy and scientific drilling methods to investigate subduction plate boundary processes and their associated hazards. She is currently leading an MBIE Endeavour Fund project to better understand hazards posed by the Hikurangi subduction zone, and is co-leading an effort to use IODP scientific drilling offshore New Zealand's North Island to understand the mechanisms behind slow slip events.