Modeling of Submarine Landslide Generated Tsunamis and Its Application in Risk Mitigation and Hazard Management at Nuclear Reactor Sites, 20-R9725Printer Friendly Version
Inclusive Dates: 07/01/07 Current
Background - An important class of natural hazards is destructive waves and associated flooding generated by tsunamis. The effects of landslide-generated tsunamis are complex and variable, and additional research is needed to develop a more comprehensive understanding of these wave hazards. Though significant progress has been made in understanding the entire tsunami evolution process from wave generation to wave run up using simplified wave equations, a more realistic and validated simulation methodology needs to be developed for improved prediction of submarine landslide-generated tsunamis. Most tsunami models to date rely on shallow water equations.
Approach - Advances in computational fluid dynamics and parallel computing have led to the application of full three-dimensional (3-D) Navier-Stokes equations for tsunami simulations. However, modeling of landslide-generated tsunamis using the full Navier-Stokes equations presents a significant computational challenge because of the complex motions and shapes of the waves. These complexities, along with the three-dimensionality of the flow field, require alternative methods that can simulate these complex flows with greater accuracy and relatively fewer computational resources. As an alternative, recent advances in mesh-free, particle-based computing methods such as smoothed particle hydrodynamics (SPH) and discrete element methods may provide equally valid models of landslide-driven tsunamis, which are considered in the present research along with a traditional flow solution approach based on the Navier Stokes equation. The present investigations emphasize developing an integrated computational methodology using both a computational fluid dynamics approach and the SPH method to evaluate tsunami hazards from landslide-generated tsunamis at coastal nuclear facilities.
Accomplishments - Extensive simulations of landslide-generated waves were conducted to evaluate the role of slide deformation on the characteristics of generated waves. These simulations highlighted both the importance and complexity of slide deformation on wave characteristics and the importance of slide rheology in tsunami hazard assessment. Several other simulations provided significant insights about the effects of slide geometry, viscosity, and turbulence on landslide-generated waves. A 3-D SPH code is being developed to simulate landslide-generated surface waves. The two-dimensional version of the code has been validated against well-known fluid dynamics base cases such as Couette Flow and Poiseuille Flow. The full 3-D version of the code is currently being developed.