Back in 2006, IT’S OUR FAULT supported Wellington to become a more resilient city through a comprehensive study of the likelihood of large Wellington earthquakes, their effects and impacts on humans and the built environment.
Today, the programme is supporting the region's growing resilience with targeted science and policy research projects in line with community and local government needs.
The southern Hikurangi subduction interface represents one of the most significant sources of seismic and tsunami hazard for the Wellington Region. Recent It’s Our Fault research has identified four earthquakes during the past 2000 years. These earthquake ages represent a major constraint for hazard models, but overall the subduction zone is still poorly understood.
In 2024-2025 the work will focus on analysing sediment cores collected over the last two years at the Parangahau Lakes near Pencarrow Head and Mātaora-Wairau Lagoon near Blenheim. The analysis will search for evidence of past subduction earthquake in the form of sudden land level change and/or tsunami. The timing and size of past events will also be examined and correlated to existing paleoearthquake records from the southern Hikurangi Zone.
Results from this work may: (1) help refine probabilistic estimates of a subduction earthquake affecting the Greater Wellington Region in the next 50 years; and (2) constrain the approximate magnitude and location of such an earthquake, with important follow-on effects for seismic hazard.
The central section of the Alpine Fault has a 75% probability of rupture in the next 50 years and there is an ~80% probability that the next earthquake will be a multi-section rupture resulting in magnitude potentially above 8. The direction of rupture also has a significant effect on the ground motions at a given site (e.g., in the Wellington Region) and the rupture direction in the next Alpine Fault earthquake is currently unknown. Ground motion modelling for the AF8 project produced relatively low shaking in the Wellington Region but the 2022 update of the New Zealand National Seismic Hazard Model produced plausible multi-segment ruptures on the Alpine Fault that could produce appreciable shaking in Wellington. This project will perform simulations of ground-motions for such potential future earthquakes.
The simulations will be performed for 3-5 rupture geometries that initiate on the Alpine Fault and extend northward towards Wellington. The ground motions (shaking) will then be calculated incorporating recent advances in modelling of sedimentary basins in Wellington and the upper South Island, as well as improvements in crustal velocity modelling, and source rupture description. The results will be compared with those from conventional empirical ground-motion models and displayed in map view and in video animations.
Modelling the impacts (e.g., damage, casualties, downtime, impacts to infrastructure) for the Wellington Region will be undertaken in 2025-2026.
A pilot study was undertaken in 2023-24 at Takapūwahia Marae, Porirua, with Ngāti Toa Rangatira to assess the impacts of multi-hazards (earthquake shaking, tsunami, liquefaction, landslides) to its facilities and community. This mahi supports decision-making, raising awareness and education and there is significant interest among other Iwi, and demand for this work for other marae in the region.
Building upon the lessons learnt from the pilot study, the team will work with Māori, Iwi partners and the IOF Programme committee to identify and codesign future case studies in the Wellington Region. A desk-based assessment will be undertaken in 2024 of the vulnerability of marae and communities to natural hazards and to identify potential communities for future engagements. These engagements will be held in 2025 to socialise the project, assess demand, interest and capacity, and to codesign projects at two marae in 2025-2026.
This project is new in 2024-2025 and aims to build capacity of communities to prepare and respond to earthquakes and natural hazards through community education programmes. Effective and culturally appropriate hazard education programmes will initially be developed for tamariki and rangatahi, including integrating such natural hazard education into wider science curricula. This will encourage the development of mental models for natural hazards, risk, and scientific uncertainty that can be used more effectively in future adult populations to encourage them to prepare for, and mitigate, natural hazard risk. This project is co-funded by QuakeCoRE and leverages off existing education projects being undertaken by research partners (including Māori) in the Wellington Region.
In 2024-2025 a pilot study will be co-led with local iwi, including kura kaupapa Maori from Otaki and Puna Matauranga students from Porirua and pacifika community. These will include a community activity on Waitangi Day, developing and testing of new materials and modules for Kura Kaupapa Māori/Schools, a codesigned programme to enhance a matauranga and iwi historical and present response knowledge to natural hazards, and a codesigned awareness and education pathways plan, to support education providers (e.g., mana whenua marae, schools, libraries, local museums, and other groups). These outputs and the knowledge generated by and within them will be shared through a variety of pathways from written reports and papers, training and briefings, public outreach, and stakeholder interactions.
A core part of the Planning and Policy project, and its predecessors, are the Science to Practice Workshops.
A core part of the Planning and Policy project, and its predecessors, are the Science to Practice Workshops. For 2024–2025 the Planning and Policy workstream will focus on completing a multi-council Science to Practice Workshop. The team will work to establish a relationship and understanding of the natural hazard planning challenges the councils face and tailor a workshop to assist in addressing these challenges.
It’s Our Fault programme datasets are currently not explicitly publicly released (e.g., on the IOF website), or consistently hosted on a single website or portal. A stocktake of legacy datasets will be undertaken to assess:
From this a plan will be developed to make them available, which will largely be undertaken in 2025-26.