2018 National Seismic Hazard Assessment: Questions and Answers

The National Seismic Hazard Assessment (NSHA) is a flagship Geoscience Australia product, used to support the decisions of the Australian Building Codes Board Standards Subcommittee BD-006-11, to ensure buildings and infrastructure are built to withstand seismic events in Australia. The NSHA has been updated in 2018 and includes significant advances on previous assessments including: inclusion of epistemic uncertainty using third-party source models contributed by the Australian seismology community, use of modern ground-motion models, and more. As a consequence of these advances, estimates of seismic hazard have decreased significantly across most Australian localities at the return period (of earthquake ground shaking) currently used by the Australian Standard. The objective of this document is to outline the significant changes to the NSHA18 from the 2012 version, and the science behind these changes. The responses were developed through feedback and consultation with experts in the seismic and engineering industry. If you have additional questions, please contact the project team at hazards@ga.gov.au.