We describe a numerical treatment for a two-layer coupled model developed for the investigation of submarine landslides and resulting tsunami generation over irregular bathymetry. The landslide model is formulated in a Cartesian coordinate system oriented with the still water level in order to facilitate coupling between water and ground motions. Motions in the upper water layer are simulated using the 3D non-hydrostatic wave model NHWAVE. Governing equations for the lower-layer landslide are integrated over the slide thickness, and include options for choosing either Newtonian viscous or granular rheology closures. The lower layer equations retain the effects of non-hydrostatic pressure, allowing the model to simulate motions over arbitrary and locally steep bathymetry. The model equations are solved using a Runge–Kutta scheme for time integration and a Godunov-type finite volume scheme for spatial derivatives, with non-conservative terms formulated using a finite difference scheme. The resulting model is verified in comparison to two laboratory experiments involving granular slide motion, and compared to observations for a field event during the 1964 Alaska earthquake.

我们描述了一种两层耦合模型的数值处理方法，该模型用于调查海底滑坡和因不规则测深仪而导致的海啸产生。滑坡模型是在以静止水位为方向的笛卡尔坐标系中制定的，以利于水与地面运动之间的耦合。使用3D非静水波模型NHWAVE模拟上水层中的运动。下层滑坡的控制方程式在滑坡厚度上积分，并包括用于选择牛顿粘性或颗粒流变闭合的选项。下层方程式保留了非静水压力的影响，从而使该模型可以模拟任意和局部陡峭测深仪上的运动。使用用于时间积分的Runge-Kutta方案和用于空间导数的Godunov型有限体积方案求解模型方程，并使用有限差分方案制定非保守项。与两个涉及粒状滑移的实验室实验进行了比较，并与1964年阿拉斯加地震期间的现场观察结果进行了比较，验证了所得模型的准确性。