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Catastrophe risk modelling firm, AIR Worldwide (AIR) has unveiled its updated earthquake model for New Zealand.
According to AIR, the model provides the most current and comprehensive view of earthquake risk as it incorporates the latest scientific research after the 2010–2011 Canterbury earthquake sequence, the 2016 Kaikoura earthquake, and earthquakes worldwide. It captures the effects from sub-perils, including ground shaking, liquefaction, landslide, tsunami, and fire following earthquakes.
The model is said to be the first to cover transocean basin tsunami risk from distant earthquakes, such as those off the western coast of South America. It features an expanded vulnerability module that includes support for additional risk types, such as large industrial facilities, infrastructure, marine cargo, and construction. This model is also said to be AIR’s first earthquake model to support land damage, because land is covered under residential policies in New Zealand.
The model was developed to meet the earthquake risk management needs of the insurance industry, AIR executive vice president and chief research officer Dr. Jayanta Guin said.
“[I]t accounts for unique risks and policy conditions specific to New Zealand,” he noted. “This includes the capability to use two seismicity models for the region.”
Guin detailed that one is a time-independent model (TID) with no memory of past rupture history; the other is a time-dependent (TD) model that considers historical or prehistorical ruptures of specific faults.
“New Zealand has a variety of faults and earthquake sources, which can produce different types of earthquakes,” AIR senior engineer and model manager Dr. Andrew O’Donnell explained. “These different earthquake types produce ground motion waves with different characteristics, so they often require their own unique ground motion models.”
Various aspects of the hazard component of the model have been peer-reviewed by local seismologists to ensure they are relevant to modelling ground motion attenuation in New Zealand and to confirm that the model agrees with the scientific consensus, he added.
