Prediction of strong ground motion pattern for the Nankai and Tonankai earthquake based on high-resokution 3D large scale numerical simulation.

为了评估未来东南开和南开地震的强地震动模式，我们首先对日本最近发生的破坏性地震进行了强地震动的计算机模拟；例如2004年kii - hando -oki地震（Mw7.3）和2004年新潟县中越地震（Mw6.8），并将模拟结果与密集阵列观测结果进行了比较。通过与观测值的比较，验证了模拟模型的准确性。因此，该模型适用于预测未来南开海槽等地震情景下的强地面运动。历史文献表明，8级地震沿着这些俯冲带反复发生，间隔时间相对均匀，约为100年，这表明下一系列8级地震将在30-40年内发生。模拟结果表明，沿震源区有大强度的发展，人口中心地区有大而长时间的地震动，主导周期较长，大阪和名古屋为3 ~ 6s，东京为6 ~ 10s。这种长时间的运动对最近的人造建筑，如高楼大厦、长桥和大型储油罐，是最具破坏性的。利用详细的地下结构模型和高性能计算机，如地球模拟器超级计算机，可以在区域尺度上进行高频地震波传播的真实模拟。这种高分辨率和高性能的系统使得对过去和未来大地震的地震波传播和强地面运动进行全面研究成为可能。

In order to evaluate the pattern of strong ground motions expecting fur future Tonankai and Nankai earthquake, we first conducted computer simulations of strong ground motions associated with recent damaging earthquakes in Japan ; such as the Kii-hanto-oki earthquake(Mw7.3) in 2004, and the Niigata-ken Chuetsu earthquake(Mw6.8) in 2004 and compared the simulation results with dense array observations.Through comparison with observations, the accuracy of the simulation model was confirmed. Thus, the model is considered to be suitable for predicting the strong ground motions for future earthquake scenarios such as events in the Nankai Trough. Historical documentation indicates that M8 earthquakes have occurred repeatedly along these subduction zones, at relatively uniform intervals of about 100 years, suggesting that the next series of M8 earthquakes should occur within 30-40 years. The simulation results warn the development of large intensity along the source region and large and lengthy ground motions in population centers, with relatively longer predominant period about 3 to 6s(Osaka and Nagoya) and 6 to 10s(Tokyo). Such long-period motions would be most damaging for recent, man-made constructions such as very tall buildings, long bridges, and large oil reservation tanks.Using the detail subsurface structural model and high-performance computer, such as the Earth Simulator supercomputer have made it possible to perform realistic simulations of high-frequency seismic wave propagation on a regional scale. Such high-resolution and high-performance systems made it possible to conduct a comprehensive study on seismic wave propagation and strong ground motions for the past and future large earthquakes.