Analysing tsunami generation through rapid accelerated sea-floor rise: a theoretical and numerical investigation based on Boussinesq-type model

Abstract

This paper describes tsunami generation through topographic rise with rapid acceleration. The phenomenon and the impact of the rapid bottom acceleration on tsunami generation were investigated both theoretically and numerically, using a Boussinesq-type model that accounts for vertical acceleration on the bottom. Analytical solutions for water depth and velocity were derived for scenarios where the bottom elevation increases according to a power law over time. The derived solutions showed good agreement with numerical simulation results. In the hydrostatic model, the solutions for both variation in water depth and velocity approached zero as the acceleration of the bottom elevation increases. In contrast, the Boussinesq-type model demonstrated that the solutions for velocity distribution changed with upward acceleration, while the solutions for water depth converged to a certain finite waveform. These findings reveal that the vertical acceleration on the bottom significantly influences the magnitude of the generated tsunami, especially affecting the velocity distribution.