SOURCE PARAMETERS OF THE 2005 ZARAND EARTHQUAKE IN KERMAN PROVINCE

On February 22, 2005, at 2h 25m 22.6s (GMT), a shallow destructive earthquake with magnitude 6.4 occurred in Zarand, Kerman province. The epicenter was calculated to be 30.78N and 56.90E. This earthquake was felt in Kerman province. The main shock was recorded by 27 stations. Furthermore, 30 aftershocks were recorded with a maximum magnitude of 4.2. There are several methods for finding source characteristics. The basis of stochastic finite fault method has the ability to combine models derived for spectra amplitude of ground motion with respect to the randomness of high-frequency motions. Some parameters that need in stochastic finite fault method are stress reduction, corner frequency, quality factor, and a rate of tectonic. Results in this study suggest that the size of main fault was about 15km in length and 9km in width. The rupture started at depth of 12 km and extended unilaterally to southeast. The best value for strike and dip were 276 and 45 degrees, respectively. The stress drop, corner frequency, quality factor and rate of tectonic were estimated as 33bar, 1.25Hz, 120 and 0.84. Rupture was initiated at (i,j)=(1,3) element and extended to southeast. In addition, the estimated fault plane solution shows the mechanism was mainly reverse and the northern block acted as a hanging wall.

کلیدواژه ها:

Source Characteristics ، Spectrum Method ، February 22 ، 2005 Zarand Earthquake