Seismic risk analysis for Mid-America communities (Illinois, Missouri)

Although public concern of seismic risk in Mid-America communities is increasing, scientific studies on seismic risk at the community level lag far behind. This study intends to develop a simple and cost-effective generic approach to seismic risk analysis for these communities.; The approach uses FEMA's HAZUS software, as well as data from ATC-21 rapid visual surveys. Based on historical seismicity, the approach divides Mid-America into three seismic source zones (small, large, and outside), makes four assumptions regarding potential earthquakes in Mid-America, and estimates probabilities of occurrences of the earthquakes. The approach considers moderate and large earthquakes separately.; The approach adopts an integrated way to design earthquake scenarios, which incorporates probabilities into the embedded deterministic approach in HAZUS. The default inventory data of HAZUS and additional data, gained from ATC-21 surveys, are used as inputs to HAZUS. The generic approach utilizes the embedded earthquake loss estimation method in HAZUS to estimate consequences of the scenarios.; This study tests the approach on three cases: the communities of Sikeston, Missouri, Carbondale, Illinois, and Urbana, Illinois. In addition, this study suggests how to extend the results from the cases to Mid-America communities. Accordingly, the most devastating earthquake for communities in the small and the large source zones (represented by Sikeston and Carbondale, respectively) would be an M8 earthquake along the New Madrid seismic fault, and in the outside source zone (represented by Urbana) an on-site M6 earthquake; the dominant seismic risk source for buildings and population in communities in the small and the large source zones is the New Madrid seismic fault, and in the outside source zone the whole of Mid-America; the dominant seismic risk source for lifelines in communities in the small source zone is the New Madrid seismic fault, and in the large and the outside source zones the whole of Mid-America. These results have positive implications for Mid-America communities. The communities can understand their seismic risk and potential problems associated with their resources. Therefore, they can take responsive measures to reduce the seismic risk and address the problems. They can also apply the generic approach to their earthquake response programs.