Tamarah King, Mark Quigley, Dan Clark

The 20th May 2016 Mw 6.1 Petermann earthquake produced a 21 km long surface rupture with a maximum vertical offset of 0.9 m. Geological and geophysical data provide strong evidence that rupture occurred along a mylonite foliation plane with an orientation defined by deformation from the nearby Woodroffe Thrust, a major Neoproterozoic terrane suture. The most geologically and seismologically reasonable fault model involves 2 bedrock-controlled faults with slightly oblique orientations. In this model, rupture propagates from a hypocentre at ≤ 4 km depth, with a centroid of slip located at the inferred intersection of the two faults at 1 km depth. No evidence of prior rupture has been identified in the landscape or in shallow trenches crossing the rupture.