New Zealand, often referred to colloquially as the “shaky isles” due to its position on the boundary between the Pacific and Australian plates, has been involved in a long-term partnership with GEM through GNS Science representatives on the Governing and Science Boards, leading the development of the GEM Faulted Earth Database and collaborating on regional initiatives.
It will now be the first country to run an end-to-end calculation using the OpenQuake-Engine. The researcher’s team led by Nick Horspool and Andrew King converted the existing national hazard model (dated back 2012) in a format compatible with the Engine, while adding new specific NZ Ground Motion Prediction Equations and Fault Scaling Laws to the OpenQuake repository. Initial results of the hazard comparison are promising (Figure 1) and if all goes well the team will soon be keen to share the model on the OpenQuake platform.
a) OpenQuake model
b)NZ National Seismic Hazard Model
Figure 1. Hazard Maps for 10% Probability of Exceedance in 50 years produced using OpenQuake (left) and the New Zealand National Seismic Hazard Model (right) – Copyright GNS 2015
In addition to at the hazard level, GNS Science has also converted all of its vulnerability and exposure models from the RiskScape project into OpenQuake formats, in order to enable risk calculations using the Engine. This will provide a continuous and uniform pathway from seismic hazard to risk modeling for New Zealand (Figure 2).
As part of the risk work, GNS has also shared the consequence data on physical damage and losses to the building stock of Christchurch in the GEM Consequences Database, for use by the whole community.
Figure 2. Results from OpenQuake Scenario Risk Calculator for a M7.5 Wellington Fault Earthquake. This model uses vulnerability and exposure data from GNS Science run in the OpenQuake Engine. Copyright GNS 2015