4.2 Rupture process of the Mainshock (Mw5.1)
The obtained hypocenter in section-3 has been used as the initiation point of rupture, and different trial planar rupture geometries were tested in the inversion using one elliptical slip patch to find the optimum geometry based on waveform fit to the strong-motion records. The WNW striking nodal plane provides a better wave-fit of 58%, suggesting that the rupture occurred on the MSH. The geometries close to the NW striking nodal plan were investigated as well, to find a rupture plane that provides the best waveform-fit to the data (Fig. 3b). The preferred geometry has a strike/dip = 292°/60°. This geometry is close to the general NW strike of the MSH in this area. However, the dip angle is 10 degrees less than the average dip of 70° proposed by Tatar et al., (2012) for the MSH.