The national seismic hazard model for New Zealand: Contributions from the deep south

Abstract

The New Zealand National Seismic Hazard Model (NSHM) is being updated for the first time since 2010 in a multi-institutional project led by GNS Science (www.gns.cri.nz/NSHM). In the interim, several major well-instrumented and well-studied earthquakes have occurred in the country. These events increased interest and awareness of seismic hazards, and necessitated urgent updates of the NSHM at the regional scale. The current national update is embracing these regional advances, but also incorporating new ideas and state-of-the-art methods in probabilistic seismic hazard analysis (PSHA). This paper is a precis of work being undertaken by our Otago earthquake science group that contributes to the NSHM update. Our work on magnitude-area scaling relations, an important but typically neglected area of PSHA, is highlighted. Efforts to revise earthquake recurrence relations, and to introduce a testing and evaluation step to the overall PSHA method are also discussed.​