Publication Date:
2015-04-01
Description:
We present a ground-motion prediction equation (GMPE) for Turkey and Iran to investigate the possible regional effects on ground-motion amplitudes in shallow active crustal earthquakes. The proposed GMPE is developed from a subset of the recently compiled strong-motion database of the Earthquake Model of the Middle East Region project (see Data and Resources ). A total of 670 Turkish and 528 Iranian accelerograms with depths down to 35 km are used to estimate peak ground acceleration, peak ground velocity, and 5% damped elastic pseudospectral acceleration ordinates of 0.01 s≤ T ≤4 s. The moment magnitude range of the model is 4≤ M w ≤8, and the maximum Joyner–Boore distance is R JB =200 km. The functional form considers three major fault mechanisms (strike slip, normal, and reverse). The nonlinear soil behavior is a function of V S 30 (average shear-wave velocity in the upper 30 m of soil profile). Our observations from empirical and estimated ground-motion trends advocate regional differences in the territories covered by Iran and Turkey that originate from the differences in Q factors, kappa, and near-surface velocity profiles. These factors eventually affect the magnitude- and distance-dependent scaling of spectral amplitudes in Iran and Turkey. In essence, the ground-motion amplitudes of these two neighboring countries would draw patterns different than the ground-motion estimates of GMPEs developed from the strong-motion databases of shallow active crustal earthquakes from multiple countries. Online Material: MATLAB code and regression coefficients for computing the response spectrum and distance scaling.
Print ISSN:
0037-1106
Electronic ISSN:
1943-3573
Topics:
Geosciences
,
Physics
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