ATC Williams undertook a site-specific Probabilistic Seismic Hazard Assessment (PSHA) to develop a Uniform Hazard Spectrum (UHS) at the bedrock level in accordance with best practice (i.e. ANCOLD, 2019), with annual exceedance probabilities (AEPs) of earthquake return periods.
Apart from ANCOLD 2019, the 2018 National Seismic Hazard Assessment for Australia is also used as a reference for seismic source and Ground Motion models. The results of this assessment were compared with the following two references.
There was a significant reduction in the seismic hazard at this site for the 2500 return period in the published hazard map NSHA18 compared to the Hazard map published in 2013 by Geoscience Australia. The key reasons for the decrease in seismic hazard factors from 2012 to 2018 seismic hazard maps are due to: