Simplified approach models tsunami-causing landslides quickly and accurately
Simplified approach models tsunami-causing landslides quickly and accurately lead image
Underwater landslides are often implicated in the formation of tsunamis. However, when a tsunami occurs, there is little time for applying the computationally demanding, detailed models needed to effectively prepare for landfall.
Researcher Peter Lo developed a simplified method for modeling landslides that can be performed quickly. By analyzing wave energies through numerical computations, Lo’s model examines the relationship between the energy of the oceanic free wave and the locked wave of the landslide. He then used the landslide and tsunami that struck Papua New Guinea in 1998 as an example to demonstrate the model’s use for real events.
The simulations show a path forward for more practical projections of how to respond to the waves.
“Given the high uncertainty in a landslide tsunami event, it may not be feasible to perform a complex numerical simulation to model the landslide tsunami generation process, because the input parameters cannot be precisely known,” Lo said. “Alternatively, by using the simple model in this study and analyzing the energy evolution curve, we can quickly come up with a conservative estimate or a representative estimate for a potential landslide tsunami event.”
He found the often overlooked locked wave component of a landslide tsunami to be as important as the free wave component. This can be relatively easily overlooked because the locked wave’s large flow velocities yield deceivingly small wave amplitudes.
By finding the peak energy generated from the landslide and the asymptotic value it then decreases to, the model can quickly provide a conservative estimate in predicting the parameters of the resultant tsunamis.
He looks to continue comparing simulations with real-world examples.
Source: “Analytical and numerical investigation on the energy of free and locked tsunami waves generated by a submarine landslide,” by Peter H.-Y. Lo, Physics of Fluids (2023). The article can be accessed at https://doi.org/10.1063/5.0144533 .
