Neotectonic fault significance

Tim Mote

This paper presents a sensitivity analysis on the significance of neotectonic faults at various slip and distance scenarios to seismic hazard ground motion estimates. The analysis implements neotectonic faults into an exemplar probabilistic seismic hazard analysis (PSHA) with no prior known neotectonic faults by iterating 15 hypothetical neotectonic distance-slip scenarios combining, five site-to-fault distances (5, 10, 20, 50, and 80 km) with three slip rate scenarios (~ 1 m/Myr, 10 m/Myr, and 100 m/Myr). The results show the relative increase in calculated ground motion through the addition of the distance-slip fault scenario as a percentage to the baseline hazard (no faults) to demonstrate the significance of neotectonic faults to seismic hazard in an Australian critical infrastructure design context. The sensitivity analysis provides insights to inform decision making in support of more detailed paleoseismological studies following initial desk study/screening level assessments of neotectonic faults near a site.