The Hauraki Rift is a tectonically active structure extending from Matamata to Waiheke Island. Because it produces earthquakes only infrequently, its seismic hazard is poorly understood. However, together, its faults are capable of generating a magnitude 7.4 earthquake. Thus, the rift poses a massive potential hazard to the 30% of NZ’s population living within 50 km. Ground Motion Simulations are used to understand the shaking hazard posed by these kinds of earthquakes at different locations around the country. There are two major obstacles with running these kinds of models. First, there are a large number of uncertainties in the input parameters: what velocity the seismic waves travel at, the length of the fault rupture, or the directivity of the event. Second, the computational burden is massive. The simulations must be performed on NZ eScience Infrastructure, and exploration of parameter space is burdensome.

A series of simulations are run to obtain a preliminary sensitivity analysis, the goal being to explore the extreme ends of parameter space. The ground motion simulation output is processed and various intensity metrics are computed, including peak ground velocities/accelerations and durations. These quantities are measured at important locations e.g. population centres larger than one thousand, economic centres like Auckland CBD and airport, and critical infrastructure. The aims are to assess the extent at which parameter uncertainty affects predictions of ground motion impact, and to develop a better understanding of which data are important to improve the model.