Analytical solutions for estimating tsunami propagation speeds

作者：An Chao^*; Liu Philip L F

来源：Coastal Engineering, 2016, 117: 44-56.

DOI：10.1016/j.coastaleng.2016.07.006

• Tsunami speed
• Earth elasticity
• Water viscosity
• Water compressibility
• Ocean stratification
• Numerical dispersion
• Analytical solution

Recent studies suggest that the tsunami speed can be slowed down by around 1% due to Earth elasticity, water compressibility and density stratification. Analytical solutions of wave dispersion relationship, accounting for such effects, were found in previous studies. In this paper, we investigate the additional effects of water viscosity, ocean stratification due to temperature salinity and numerical dispersion. Theoretical solutions are derived and checked with known solutions. All the formulas are then simplified for long tsunamis waves so that the propagation speed can be calculated explicitly. The simplified solutions are evaluated using realistic geophysical parameters. For a typical tsunami wavelength of similar to 200km, the viscous effect is found to be negligible; ocean stratification due to temperature/salinity causes significant speed reduction because of the high density change rate, which has been ignored before. We also evaluate the numerical dispersion of tsunami simulations, which is shown to be potentially comparable to physical dispersion.

• 出版日期2016-11
• 单位中央民族大学