A scenario approach to estimate the maximum foreseeable loss for buildings due to an earthquake in Cape Town

Abstract

A methodology for the assessment of the probable maximum loss associated with an earthquake is described and applied to the Cape Town central business district. The calculations are based on the effect of the two largest earthquakes that occurred in Milnerton in 1809 and Ceres–Tulbagh in 1969. The investigation concludes that if buildings and infrastructure in an area follow the SANS Standard 10160 for seismic loading of 0.1 g, they are exposed to significant seismic risk. The main purpose of this research is not the accurate quantification of expected losses to Cape Town’s infrastructure, but to raise awareness between civil engineers, the insurance industry and disaster management agencies that seismic hazard is an issue in South Africa and must be considered as a potential threat to its residents and infrastructure.

Keywords: Probable maximum loss (PML); seismic risk; hazard; expected damage; Cape Town; short-term insurance