越洋海啸的数值模拟

Preliminary study on numerical simulation of transoceanic tsunami

破坏性海啸基本上都是越洋海啸,如1960年智利海啸、2004年苏门答腊海啸。越洋海啸的传播机制与近场海啸不同,进行数值模拟所采用的数学模型也不同。本文分析比较Boussinesq方程和线性浅水方程,选用后者作为进行越洋海啸数值模拟的数学模型,基于有限差分法,运用蛙跃格式求解微分方程。以2004年苏门答腊海啸作为算例,把计算结果与NOAA和NGDC的计算结果进行对比,验证本文的数学模型和计算方法的可靠性,为以后进一步的海啸危险性分析和海啸预警等研究工作提供技术支持。

Most transoceanic tsunamis are destructive, such as 1960 Chile tsunami and 2004 Sumatra tsunami. The propagation mechanisms of transoceanic tsunami and near-field tsunami are different, so are the mathematical models. In this paper, based on the finite difference method, the leap-frog scheme is used to solve the linear shallow equations by comparing with Boussinesq equations. As an example, 2004 Sumatra tsunami is simulated, and the calculation results are compared with those provided by NOAA and NGDC. The methodology suggested in this paper will give the technological support to the tsunami hazard analysis and the tsunami warning service.