Mehdi Bahrekazemi - Division of Soil and Rock Mechanics, Royal Institute of Technology, Stockholm, Sweden,
Anders Bodare - Division of Soil and Rock Mechanics, Royal Institute of Technology, Stockholm, Sweden

Technical achievements made in recent years have made it possible to install an Earthquake Warning System (EWS) that can issue alarm a few seconds before the damaging waves reach the area. The main idea behind such systems is to make use of the difference between the propagation velocity of S waves, and radio waves,to issue earthquake alarm before arrival of the damaging seismic waves to the area. As the efficiency and economical aspect of an EWS depends on many factors, each area must particularly be studied in order to determine if such a system would be appropriate or not.In this paper EWS has been studied as a complementary measure against earthquakes in Iran, a country with more than 100,000 casualties due to earthquakes in recent decades. A simplified method has also been suggested for comparing the costs of the project with its economical advantages. Using the suggested method it has been shown that an EWS would be both economical and efficient in some parts of the country