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.