TY - GEN

T1 - Influence of velocity distribution and density stratification on generation or propagation of tsunamis

AU - Kakinuma, T.

AU - Nakamura, K.

AU - Yamashita, K.

AU - Nakayama, K.

PY - 2011/1/1

Y1 - 2011/1/1

N2 - A set of wave equations derived on the basis of a variational principle in consideration of both strong nonlinearity and strong dispersion of surface/internal waves is numerically solved to simulate generation and propagation of tsunamis in the vertical two-dimension. The velocity potential in each fluid layer is expanded into a power series of vertical position, such that the accuracy of vertical distribution of velocity depends on the number of expansion terms. Numerical results of surface displacement are compared with the existing experimental data, where tsunamis are generated by the seabed uplift. When the fundamental equations are reduced to nonlinear shallow water equations, the numerical model cannot represent propagation of a long wave group especially in distant-tsunami propagation, leading to overestimation of both the wave height and wave steepness of the first wave. The wave height becomes larger in the stratified ocean than that in a one-layer case, although the present density distribution hardly affects the tsunami phase over a long-distance travel.

AB - A set of wave equations derived on the basis of a variational principle in consideration of both strong nonlinearity and strong dispersion of surface/internal waves is numerically solved to simulate generation and propagation of tsunamis in the vertical two-dimension. The velocity potential in each fluid layer is expanded into a power series of vertical position, such that the accuracy of vertical distribution of velocity depends on the number of expansion terms. Numerical results of surface displacement are compared with the existing experimental data, where tsunamis are generated by the seabed uplift. When the fundamental equations are reduced to nonlinear shallow water equations, the numerical model cannot represent propagation of a long wave group especially in distant-tsunami propagation, leading to overestimation of both the wave height and wave steepness of the first wave. The wave height becomes larger in the stratified ocean than that in a one-layer case, although the present density distribution hardly affects the tsunami phase over a long-distance travel.

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U2 - 10.1142/9789814366489_0193

DO - 10.1142/9789814366489_0193

M3 - Conference contribution

AN - SCOPUS:85066761635

SN - 9789814366489

T3 - Asian and Pacific Coasts, 2011 - Proceedings of the 6th International Conference

BT - Asian and Pacific Coasts, 2011 - Proceedings of the 6th International Conference

A2 - Lee, Joseph Hun-Wei

A2 - Ng, Chiu-On

PB - [publishername] World Scientific

T2 - 6th International Conference on Asian and Pacific Coasts, APAC 2011

Y2 - 14 December 2011 through 16 December 2011

ER -