By understanding earthquakes and the hazards they cause, we can work to build a more earthquake-resilient society.
Land of the long complex plate boundary
Aotearoa New Zealand straddles the Pacific and Australian tectonic plates. These plates are colliding with huge force, causing one to slowly grind over, under or alongside the other. As the brittle crust gives way under the pressure, a fault ruptures and an earthquake is unleashed. Every year, GNS Science records over 20,000 earthquakes in New Zealand. About 100-150 of these quakes are large enough to be felt – the others we only know about because they are recorded by seismographs.
The team at GNS Science leads and contributes to a variety of research efforts to understand our earthquakes and the associated hazards and risks they pose to New Zealand. Our research ensures our communities are prepared and resilient.
New Zealand's Plate boundary – New Zealand is located on the boundary of two of the world’s major tectonic plates – the Pacific Plate and the Australian Plate, this animation shows how the plates interact. transcript
In New Zealand, the Australian and Pacific Plates push against each other along a curving boundary. How they meet each other changes along this boundary. At the southern end of the South Island, the Australian Plate dives down below the Pacific Plate. In the North Island the opposite situation occurs with the Pacific Plate being pushed under by the Australian Plate. In between, through most of the South Island, the two plates grind past each other along the Alpine Fault.
Earthquake monitoring and response
Nationwide, there are hundreds of seismographs and strong motion sensors monitoring thousands of small shakes and many large quakes per year. Continuous GPS is being used to monitor “slow” earthquakes, recording land movement down to a few millimetres. These data are acquired, collected, stored and made available for research and monitoring by the GeoNet programme.
GeoNet is a collaboration between GNS, Toka Tū Ake EQC and Toitū Te Whenua LINZ and includes the National Geohazards Monitoring Centre (NGMC), which contributes significantly to the analysis of seismic data and monitors seismic activity around the country. Earthquake monitoring feeds into applications such as emergency response and the rapid analysis of possible tsunami. Through a number of programmes, GNS works to develop and maintain scientific capability to rapidly assess and analyse earthquakes, ensure timely and accurate advice is provided to emergency management and stakeholders and inform the public about the event.
One of the goals of natural hazard research is to help communities build resilience. We work to deliver earthquake research that supports the aspirations of communities to increase their resilience. Specifically, we contribute earthquake-specific knowledge and data to hazard and risk modelling so that communities can predict and respond to multi-hazard scenarios. We also partner with research groups and communities to inspire, educate and facilitate a deeper understanding of our hazard-prone nation.
We incorporate several fields of study in our research to best understand earthquakes in the context of our complex plate boundary. Our research involves models of earthquakes and their ground motions (seismology), earthquake geology, geodynamics and geodesy.
We contribute our expertise in these fields to a variety of projects, drawing on our wide range of disciplines. Recent projects and programmes we have led and supported include Resilience to Nature’s Challenges, Rapid Characterisation of Earthquakes and Tsunami (RCET), National Seismic Hazard Model (NSHM) and It’s Our Fault.