The 2012 Australian Seismic Hazard Map - Introduction and Approach

Geoscience Australia is currently drafting a new Australian Earthquake Hazard Map (or more correctly a series of maps) using modern methods and models. Among other applications, the map is a key component of Australia’s earthquake loading code AS1170.4. In this paper we provide a brief history of national earthquake hazard models in Australia, with a focus on the map used in AS1170.4, and provide an overview of the proposed changes for the new maps. The revision takes advantage of significant improvements in both the data sets and models used for earthquake hazard assessment in Australia since the original map was produced. These include:  Earthquake observations up to and including 2010  Improved methods of declustering earthquake catalogues and calculating earthquake recurrence  Ground-motion prediction equations (i.e. attenuation equations) based on response spectral acceleration rather than peak ground velocity, peak ground acceleration or intensity-based relations.  Revised earthquake source zones  Improved maximum magnitude earthquake estimates based on palaeoseismology  The use of open source software for undertaking probabilistic seismic hazard assessment which promotes testability and repeatability The following papers in this series will address in more detail the changes to the earthquake catalogue, earthquake recurrence and ground motion prediction equations proposed for use in the draft map. The draft hazard maps themselves are presented in the final paper.