Survey of Kalgoorlie Earthquake Damage

Australia has a low seismicity when compared to countries located along tectonic plate boundaries. Seismic risk, however, is the combination of hazard, community exposure and infrastructure vulnerability. The legacy of older unreinforced masonry buildings is a particular subset of the built environment that may contribute disproportionately to community risk. Documented information on the damage to buildings caused by earthquake events is fundamental to understanding this risk. The Earthquake Earlier this year on the 20th April a magnitude 5.0 (ML) earthquake shook the Western Australian goldfields town of Kalgoorlie. The earthquake was shallow (1.7 km) and was located immediately south of the business district of the Kalgoorlie suburb of Boulder (refer Figure 1). The severity of ground motion was found to vary markedly across the town with the older masonry building stock in Boulder experiencing a greater intensity of shaking than the corresponding building age group in the Kalgoorlie business district 4 km away. The event has provided the best opportunity to examine the earthquake vulnerability of Australian buildings since the Newcastle Earthquake of the 28th December 1989, over twenty years prior. The Survey Following the earthquake Geoscience Australia (GA) arranged a staged collaborative survey that would capture information from which vulnerability knowledge could be derived.