Co-seismic surface deformation relating to the March 23, 2012 Mw5.4 Ernabella (Pukatja) Earthquake, intraplate central Australia
Authors / CoAuthors
de Kool, M.
On 23 March 2012, at 09:25 GMT, a MW 5.4 earthquake occurred in the eastern Musgrave Ranges region of north-central South Australia, near the community of Ernabella (Pukatja). This was the largest earthquake to be recorded on mainland Australia for the past 15 years and resulted in the formation of a 1.6 km-long surface deformation zone comprising reverse fault scarps with a maximum vertical displacement of over 50 cm, and extensive ground cracking. Numerous small communities in this remote part of central Australia reported the tremor, but there were no reports of injury or significant damage. The maximum ground shaking is estimated to have been in the order of MMI VI. The earthquake occurred in Stable Continental Region (SCR) crust, over 1900 km from the nearest plate boundary. Fewer than fifteen historic earthquakes worldwide are documented to have produced coseismic surface deformation (i.e. faulting or folding) in the SCR setting. The record of surface deformation relating to the Ernabella earthquake therefore provides an important constraint on models relating surface rupture length to earthquake magnitude. Such models may be employed to better interpret Australia's rich prehistoric record of seismicity, thereby improving estimates of seismic hazard.