SIMULATION OF STRONG MOTION RECORDS OF TOHOKU(2011), JAPAN EARTHQUAKE USING EMPIRICAL GREEN'S FUNCTION TECHNIQUE

Abstract

A method for estimating the rupture model with the aid of the Empirical Green's Function (EGF) technique is presented in this work which uses aftershock associated with large earthquake as Green's Function. The rupture responsible for an earthquake has been represented by several subfaults. The geometry of these subfaults and their number is decided by the law of self similarity. To test this method the strong motion data of the Tohoku earthquake which occurred on 11th of March,2011, Japan (MAMA= 9.0) has been simulated using three aftershocks associated with them recorded by KiK-NET. The source of this earthquake is modeled by a simple rectangular rupture plane of size 510 x 210 square km, buried at a depth of 10 km in a multilayered earth model. Strong motion record at three selected near-field stations are simulated and compared with the observed records and their response spectrum. The comparison of observed and simulated record confirms the suitability of final parameters of rupture model causing this earthquake. Iterative modeling and comparison of actual and simulated record usingthe root mean square error as a tool for comparison support a rupture velocity of 3.1 km/sec, and nucleation point near to the centre of the rupture plane and nucleating with a dip angle of 13.°