Analysis of seismic intensities observed in Israel

Macroseismic data of earthquakes felt in Israel and also recorded instrumentally are analyzed. The analysis yields the following empirical relations: {Mathematical expression} where M is the local magnitude, Î is the expected seismic intensity (MSK-scale), R is the epicentral distance, I_tE is the average seismic intensity in the focal area (within 20 km), and D is the radius of the area in which seismic intensities of grade III or more were observed, σ is the one standard deviation. Using macroseismic observations in Israel following distant-earthquakes and by using the empirical attenuation function (see above), an attempt is made to identify areas within Israel with unusual response. The results indicate a poor correlation between the intensity response of a site and its geological and geotechnical properties.