Attenuation and propagation characteristics of seismic waves in Iran

Category Tectonic & Seismotectonic
Group GSI.IR
Location 4th internetional Conference on Seismology
Holding Date 11 March 2008
     Seismic wave propagation of crustal phases for Iranian earthquakes is examined through different parts of Iran by studying records from the Iranian National Seismological Network (INSN), stations of Mashad University and Iranian Long Period Array (ILP A). The selected crustal phases for analysis were P (Pn or refracted P), Pg, Sn and Lg. Three component rotated seismograms were bandpass filtered (0.1 to 5 Hz) and the presence and amplitude of Sn and Lg were examined relative to the Pn and Pg phases. Also, the data of Iranian stations were used to detennine coda Q over a small area (200 km by 200 km) for small earthquakes. According to this research, Q varies with frequency in different parts of Iran as follows:
Western Iran: Q=105 f1.02
North-Central Iran: Q=147 fo.97
South-Central Iran: Q= 138 f 1.06 North-Eastern Iran: Q=151 f1.01 Eastern Iran: Q=169 fo.86
South-Eastern Iran: Q=194 fo.77
The results of previous works such as Rodgers et al. (1997) were used to complete the gaps of Iranian records in some parts of Iran.

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