The M_w 6.3 Shonbeh (Bushehr) mainshock, and its aftershock sequence: Tectonic implications and seismicity triggering

Authors : Hiwa MOHAMMADI, Yusuf BAYRAK

Pages : 43-56

View : 17 | Download : 8

Publication Date : 2015-09-28

Article Type : Other Papers

Abstract :In this study, the statistics properties of the aftershock sequence and Coulomb stress changes due to the mainshock of the  = 6.3, 9 April 2013 Shonbe earthquake have been studied. The spatial distribution of aftershocks and focal mechanism event with ≥5.0 declared a NW–SE striking rupture with oblique thrust fault mechanism. The b -value is estimated as 0.77± 0.05 and the mainshock occurred in a highly stressed region and sequence comprised larger magnitude aftershocks due to the presence of large size asperities within the rupture zone. Also the high p -value insert ignore into journalissuearticles values(1.16 ± 0.05);, implying fast decay rate of aftershocks, evidences high surface heat flux. A value of the spatial fractal dimension insert ignore into journalissuearticles values( ); equal to 2.60 ± 0.02 indicates random spatial distribution and source in a two-dimensional plane that is being filled-up by fractures. Moreover, the evaluated coseismic Coulomb stress using the variable slip model for depth range 0–20 km reveals a ‘butterfly’ pattern and most of the aftershocks fall insert ignore into journalissuearticles values(95%); in the region of enhanced Coulomb stress. 
Keywords : Shonbeh Earthquake, aftershock sequence, statistics properties, Coulomb stress changes, spatial distribution