基于GeoClaw海啸数值模拟程序对2011年日本东北大地震有限断层模型的验证

由于海啸波具有长周期、慢衰减的特征, 对于能够激发海啸的海底地震, 海啸波资料一定程度上可以作为利用地震波资料和大地测量资料反演得到的震源有限断层模型的补充数据, 以验证该模型的合理性. 本文以2011年日本东北大地震海啸期间反演的震源模型为例, 利用Okada弹性半无限空间理论将震源有限断层模型转化为垂向海底变形; 然后利用GeoClaw海啸数值模型进行海啸数值模拟, 在计算区域模拟实际观测点的海啸波波形数据; 并将模拟海啸波波形数据与实际观测值进行对比, 以验证震源有限断层模型的可靠性.

Verification of finite fault model of the 2011 Tohoku Tsunami based on GeoClaw tsunami simulation model

Tsunami waves are characterized by long periods and slow subsidence. For the submarine earthquake triggering a tsunami, the tsunami waveform data can be used as supplementary data for verifying the rationality of the finite fault model obtained by inversion of seismic wave data and geodetic data. Taking the earthquake source of the 2011 Tohoku tsunami as an example, we transform the finite fault model into vertical variation in the seabed topography according to Okada elastic half-space theory. Then we use the GeoClaw tsunami model to perform the tsunami simulation. Some monitoring points in the calculation domain are set on those points which can be utilized to obtain the tsunami waveform data. By comparing the simulated tsunami waveform data with the actual observation data, we analyze the reliability of the models and verify the effectiveness of most reasonable finite fault model of the earthquake.