夏威夷ALEUTIAN海啸的NEOWAVES数值模拟

SIMULATION OF ALEUTIAN TSUNAMI BY NEOWAVES MODEL

夏威夷群岛因其特殊的地理位置及周围海底地形,长期遭受太平洋地震带和近岸地震带产生的海啸影响,如何准确地确定夏威夷群岛沿岸的海啸爬高对海洋结构设计具有重大意义。基于非线性浅水方程建立的NEOWAVES模型包含非线性静水压力项和垂向动量方程,用于描述海底的动态变形和弱频散波的传播过程,它能够模拟海啸的整个生命过程,包括产生、传播、爬高和淹没。以对夏威夷地区影响比较严重的1946年Aleutian历史海啸为例,采用NEOWAVES模型模拟其产生、传播以及在夏威夷欧胡岛沿岸地带的爬高。计算结果表明,NEOWAVES模型计算得到的欧胡岛沿岸(北部、西部和南部)的爬高与历史记录的爬高数据接近,验证了NEOWAVES模型的合理性和可靠性,同时也为夏威夷地区海洋结构物的设计提供合理的参考意见。

Hawaiian Islands have long been impacted by tsunamis caused by the Pacific seismic zone and near-field seismic zone, largely attributed to its special geographical location and its offshore geography. How to accurately calculate the tsunami runup along the coast of Hawaiian Islands is of great significance on the design of marine structures. Based on the nonlinear shallow water equation, NEOWAVES is a shock-capturing, dispersive wave model for tsunami generation, basin-wide evolution, and run-up. It utilizes non-hydrostatic pressure and vertical velocity terms to describe dispersion and time-varying seafloor deformation. In this study, the NEOWAVES model is applied to the simulation of generation, propagation and runup of the 1946 a Aleutian historical tsunami at Oahu Island. The result shows that the tsunami runup data at Oahu Island（North, West and South） calculated by NEOWAES model are similar to the historical recorded runup data, which proves that the NEOWAVES is rational and reliable to simulate tsunami, and offers reasonable reference on design of marine structure.