Numerical modeling for seismic cycle of great interplate earthquakes along the Nankai trough following a friction law

对南开海槽大板间地震周期的数值模拟进行了如下研究。(1)在有限元模拟中引入摩擦规律，模拟粘弹性非均质介质中的地震周期。我们建立了一个二维粘弹性有限元模型，其中一个板块在一个地壳和地幔楔的岛弧下俯冲，并沿板块界面分配了深度为70 km的摩擦参数。(2)采用基于块弹簧模型的多种摩擦规律模拟地震发生，并与地震发生的观测统计量进行比较。(3)利用地震板块的地壳下地震分布和深层地震板块的层析成像技术，构建了沿日本西南部南开海槽俯冲的三维菲律宾海板块。

The following researches were made for the numerical modeling of seismic cycle of great interplate earthquakes along the Nankai trough.(1) We implemented a friction law in FEM modeling to simulate seismic cycle in a viscoelastic heterogeneous medium. We constructed 2-D viscoelastic FEM model where a plate is subducting beneath an island arc with a crust and a mantle wedge and assigned frictional parameters down to a depth of 70 km along the plate-interface.(2) We simulated earthquake generation using a variety of friction laws based on block-spring model to compare the results with the observed statistics of earthquake occurrence.(3) We constructed the 3-D Philippine Sea plate subducting along the Nankai trough beneath southwest Japan, using the distribution of subcrustal earthquakes for the seismic slab and a tomographic technique for the aseismic slab in the deeper portion.