Predicting the likely consequences of an earthquake to a nation, a city or an individual facility is generally covered by the scientific field of seismic risk assessment, often referred to as “Earthquake loss estimation (ELE)”.
Seismic risk assessment is a comparably young discipline, which basically began with the seminal works on earthquake hazard by Luis Esteva and Allin Cornell in the late 1960s. An elementary definition of this discipline was given by the EERI Committee on Seismic Risk in 1984, according to which “seismic risk is the probability that social and economic consequences of earthquakes will equal or exceed specified values at a site, at various sites or in an area during a specified exposure time”.
Earthquake loss estimation studies establish a central component in the causal chain from the basic research disciplines involved to prevention and mitigation actions against the causes of the natural hazard earthquakes (see Figure). The main purpose of earthquake loss assessment studies is to generate reliable estimates of expected physical damage as well as the economic and social losses that are connected to the damages either in a direct or indirect way. Based on the identification of existing weaknesses, e.g. the disproportionate damage extent of a certain building typology, strengthening and retrofitting measures can be proposed. Thus, earthquake loss assessment studies can directly contribute to the prevention of future losses.
The causal chain from basic research disciplines to preventive actions through earthquake loss estimation. The key for reducing earthquake damages is to reduce physical (building-related) vulnerability as well as increase societal resilience, based on an underlying knowledge of earthquake hazard and risk. A number of well-proven preventive measures can be activated for this mitigation purpose (Bungum and Lang, 2010).