، در منطقه البرز به كمك داده هاي ميدان نزديك حركت نيرومند زمين لرزه كجور در محدوده بسامدي 1 تا 23 هرتز QB تعيين فاكتور كيفيت امواج برشي مستقيم

Attenuation of shear-waves in the Alborz region for frequencies from 1 to 32 Hz, using near field accelerograms obtained during Balade-Kojour earthquake

Near-field data obtained from the main shock of May 28, 2004 Baladeh-Kojour earthquake, with Mw = 6.2 is used to determine the frequency dependence of direct shear wave quality factor Q? , in the range of 1 to 32 Hz .Based on the regression analysis, the following equation is proposed: Q? = 90f 0.74 High attenuation factor and frequency dependence of quality factor for shear waves imply the high seismicity of the region and agrees well with similar studies in other seismically active regions such as Greece, Japan, India, etc.