New Zealand is one of the most earthquake-prone countries in the world due to its location along the boundary between the Pacific and Australian tectonic plates.
Each year, more than 15,000 earthquakes are detected and located by GeoNet, most too small, too deep, or too far offshore to be felt. Still, destructive earthquakes can occur at any time.
Historical records dating back to the 1840s show that the country can expect a magnitude 6 earthquake on average every year and a magnitude 7 earthquake roughly every 10 years.
The most recent damaging event was the magnitude 7.8 Kaikōura earthquake in November 2016, while the deadliest was the February 2011 Christchurch earthquake, which killed 185 people and caused more than NZ$40 billion in economic losses, including insurance claims.
Earthquakes and their impact on critical infrastructure
Major earthquakes disrupt essential infrastructure such as roads, water networks, power systems, and communication lines. These disruptions directly affect people’s access to basic needs like food, water, medical care, and emergency services. The longer these outages last, the greater the economic losses and the greater the strain on communities trying to recover.
Given New Zealand’s high vulnerability and history of severe earthquakes, emergency management departments need tools that help communities anticipate disruptions and prepare for them before disaster strikes.
A new tool for visualizing infrastructure outages
A 2024 study published in Progress in Disaster Science outlines the development of a web tool designed for the Wellington region to visualize potential infrastructure outages after a rupture of the Wellington Fault. The tool serves three primary groups:
- Critical Infrastructure Owners – They can identify where upgrades may be needed to maintain reliable service after a major fault rupture and strengthen their emergency response plans.
- Communities – Residents can see how outages could affect their households, including walking distances—shown in both kilometers and minutes—to access essential resources like food and water during prolonged disruptions.
- Emergency Management Sector – Agencies can understand gaps in essential services, identify which communities may need additional support, and plan emergency response strategies based on anticipated service outages.
Supporting planning through the PELOS framework
To help communities and service providers plan for major emergencies, the Wellington Lifelines Group (WeLG) and the Wellington Region Emergency Management Office (WREMO) created the Planning Emergency Level of Service (PELOS) framework. Infrastructure providers often use the term “level of service” to describe asset performance, but few offer measurable, time-bound emergency-specific service commitments.
One notable exception is Wellington Water’s emergency service target:
20 liters of water per person, per day, within 1 km of homes by day 8 after an event.
This publicly stated target reflects Wellington Water’s emergency planning strategy and demonstrates practical application of the PELOS framework.
However, other sectors, such as energy, telecommunications, and transport, lack equivalent publicly available targets, making it more challenging to develop comprehensive PELOS goals across the wider infrastructure system.
How the mapping tool supports better resilience
The mapping tool helps emergency management teams explain to communities what a Wellington Fault rupture could mean for them and how to prepare. It visualizes infrastructure outages, shows public walking distances to essential resources, and highlights areas of good or poor coverage for planners.
Although the tool currently focuses on a single hazard, it provides a valuable demonstration of the potential impacts of a significant earthquake in the region.
By using insights from this tool, households, infrastructure providers, and emergency management professionals can better plan for emergency levels of service, ultimately improving community resilience.
Built on open-source data and developed through collaboration with academic researchers, critical infrastructure organizations, and emergency managers, the tool can be adapted for other regions and hazards, including earthquakes, floods, storms, landslides, and more.
Access the web tool.
Source:
Mowll, R., Anderson, M. J., Logan, T. M., Becker, J. S., Wotherspoon, L. M., Stewart, C., Johnston, D., & Neely, D. (2023). A new mapping tool to visualise critical infrastructure levels of service following a major earthquake. Progress in Disaster Science, 21, 100312. https://doi.org/10.1016/j.pdisas.2024.100312
Earthquakes in Aotearoa New Zealand. (2024). Retrieved from https://www.naturalhazardsportal.govt.nz/s/natural-hazard-risk/about-natural-hazard-risk/earthquake#
Canterbury Earthquakes. (n.d.) ICNZ. Retrieved from https://www.icnz.org.nz/industry/canterbury-earthquakes/
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