1. Surrealism in Facing the Earthquake Risk

The possibility of a violent ground motion in a population center poses multiple threats to the safety and continuity of society. It has to be met on multiple planes including the political and the economical. It is not an exaggeration to claim that the construction trades in many parts of the world understood the threat only in twentieth century. In many towns and cities in seismic zones, a strong ground motion can destroy 10 % or more of the existing buildings. To locate the vulnerable, it is necessary to investigate all. If this study is to be done in detail using codified criteria, it may involve an investment that would be unacceptable to a political system that seldom appreciates the risk. That condition constrains the engineering effort to the minimal and requires a procedure that has to be simple and transparent. Above all, data acquisition needs to be within the reach of workers without technical degrees. The paper investigates such a procedure, the Hassan Index, using available information from five earthquake events and finds it imperfect but useful.