In models of triggered seismicity and in their inversion with empirical data, the detection threshold md is commonly equated to the magnitude m0 of the smallest triggering earthquake. This unjustified assumption neglects the possibility of shocks below the detection threshold triggering observable events. We introduce a formalism that distinguishes between the detection threshold md and the min...

Several radial basis function based methods contain a free shape parameter which has  a crucial role in the accuracy of the methods. Performance evaluation of this parameter in different  functions with various data has always been a topic of study. In the present paper, we consider studying the methods which determine an optimal value for the shape parameter in interpolations of radial basis  ...

Despite the various studies carried out to evaluate effects of seismic sequences on structures, matter time gap required be considered between mainshock and its corresponding aftershocks in dynamic analyses has never been focused directly. This subtle but meantime effective subject, influences amount accumulated damage caused by earthquake sequences. In present study, 244 near fault ground moti...

This study investigates geometrical non-linear analysis of composite circular cylindrical shells under external pressure over part of their surfaces and also shells subjected to combined axial compression and triangular external pressure. Donnell non-linear shell theory along with first order shear deformation theory (FOSD) are adopted in the analysis. In the case of combined axial compression ...

[1] We compute and analyze P wave spectra from earthquakes in southern California between 1989 and 2001 using a method that isolates source-, receiver-, and pathdependent terms. We correct observed source spectra for attenuation using both fixed and spatially varying empirical Green’s function methods. Estimated Brune-type stress drops for over 60,000ML = 1.5 to 3.1 earthquakes range from 0.2 t...

Assume that each earthquake can produce a series of aftershock independently of its size according to its “local” Omori’s law with exponent 1+θ. Each aftershock can itself trigger other aftershocks and so on. The global observable Omori’s law is found to have two distinct power law regimes, the first one with exponent p− = 1− θ for time t < t ∗ ∼ κ−1/θ, where 0 < 1−κ < 1 measures the fraction o...

Aftershocks are the most striking evidence of earthquake interactions and the physical mechanisms at the origin of their occurrence are still intensively debated. Novel insights stem from recent results on the influence of the faulting style on the aftershock organisation in magnitude and time. Our study shows that the size of the aftershock zone depends on the fault geometry. We find that posi...

one of the methods for the determination of focal mechanisms of earthquakes is the linear inversion of moment tensor in time domain. that method is used here for determining of the focal mechanisms the darbe astaneh silakhor earthquake of 31 march 2006 and two of its foreshocks and six aftershocks with local magnitude more than 4. the data of six broadband stations of the international institut...