MACROSEISMIC INTENSITY ATTENUATION FOR CRUSTAL SOURCES ON ROMANIAN TERRITORY AND ADJACENT AREAS

The macroseismic intensity attenuation (m.i.a.) laws for the main seis mic provinces with crustal foci of the Romanian territory and adjacent areas were established. The input data consist of MSK-64 intensities of 18 earthquakes with epicentral/maximum intensity in the range V to X degrees (MSK scale), whose isoseismal maps were available. The atten uation was analyzed as a function of distance and azimuth and from the three main attenuation formulas (logarithmic, exponential, and power- law) (the last one was preferred, as it best fits the observed data) a nd, consequently, were used for each seismogenic region. The bulk of d erived equations is intended to be further used in the assessment of t he seismic hazards of Romania.