Seminar: Tsunami Generation Mechanism of Historical Hawaii Local Tsunamis

Dr. Yoshiki Yamazaki Assistant Researcher Department of Ocean & Resources Engineering University of Hawai’i at Mānoa   The 4 May 2018 MW  6.9 earthquake offshore of Kilauea Volcano at Hawaii Island has raised concern to emergency management agencies in Hawaii because of locally generated tsunami’s short arrival time and unpredictable amplitude along the Hawaiian Islands. Fortunately, the tsunami impact of the 2018 MW  6.9 earthquake was moderate over the entire Hawaii island chain. However, Hawaii experienced two larger earthquakes in recorded history, the 1975 MW  7.7 Kalapana and 1868 M ~7.9 Ka`u earthquakes at the south flank of Hawaii Island.

Seminar: Numerical Dispersion in Non-Hydrostatic Modeling of Tsunami Propagation

Linyan Li, PhD Post-Doctoral Research Fellow Department of Ocean and Resources Engineering, University of Hawai’i at Mānoa Numerical discretization with a finite-difference scheme is known to introduce frequency dispersion in depth-integrated models commonly used in tsunami research and hazard mapping. While prior studies on numerical dispersion focused on the linear shallow-water equations, we include the non-hydrostatic pressure and vertical velocity through a Keller box scheme and investigate the properties of the resulting system in relation to a hydrostatic model. Fourier analysis of the discretized governing equations gives rise to a dispersion relation in terms of the time step, grid size, wave

PhD Defense: Numerical dispersion in non-hydrostatic modeling of long-wave propagation

Linyan Li Numerical discretization with a finite-difference scheme is known to introduce truncation errors in the form of frequency dispersion in depth-integrated models commonly used in tsunami research and hazard mapping. While prior studies on numerical dispersion have focused on the shallow-water equations, we include the depth-integrated non-hydrostatic pressure and vertical velocity through a Keller-box scheme and investigate the properties of the resulting system. Fourier analysis of the discretized governing equations gives rise to a dispersion relation in terms of the time step, grid size, and wave direction. The interworking of the dispersion relation is elucidated by its lead-order approximation,