New Physical Insight into Landslide-Tsunamis Using Non-Linear Wave Decomposition

Constance, Ben; Heller, Valentin

Abstract

Potentially devastating tsunamis are generated by landslides impacting into water bodies. Such subaerial landslide-tsunamis are typically predicted with empirical equations, which, however, fail to appropriately capture some of the underlying physics. Considering the spectral composition of subaerial landslide-tsunamis provides new physical insight into subaerial landslide-tsunamis and in predicting their future behaviour. This work introduces the University of Nottingham Insight into Ocean-wave Non-linear Superposition (UNIONS) software package for MATLAB which uses a nonlinear Fourier transform in one spatial dimension based on the Korteweg–de Vries (KdV) equation to characterise shallow-to intermediate-depth gravity waves. This article describes the Inverse Scattering Transform methodology behind the software. The code’s application to landslide-tsunami characterisation is discussed and demonstrated by analysis of laboratory flume experiments. Cnoidal spectral decompositions of experimental data are obtained, allowing nonlinear filtering to be performed and solitary wave components to be identified. These results are compared with a traditional linear Fourier analysis. The UNIONS decomposition, which consists of physical solutions to the KdV equation, is shown to provide greater insight into the data. Future work will extend UNIONS to two spatial dimensions using the Kadomtsev-Petviashvili equation and potential applications beyond water gravity waves will be examined.

Citation

Constance, B., & Heller, V. (2022). New Physical Insight into Landslide-Tsunamis Using Non-Linear Wave Decomposition. In Proceedings of the 39th IAHR World Congress (Granada, 2022) (6234-6243). https://doi.org/10.3850/IAHR-39WC2521711920221094

• Presentation Conference Type: Edited Proceedings
• Conference Name: 39th IAHR World Congress
• Start Date: Jun 19, 2022
• End Date: Jun 24, 2022
• Acceptance Date: Jun 19, 2022
• Publication Date: 2022
• Deposit Date: Jan 8, 2024
• Publisher: International Association for Hydro-Environment Engineering and Research
• Pages: 6234-6243
• Book Title: Proceedings of the 39th IAHR World Congress (Granada, 2022)
• ISBN: 9789083261218
• DOI: https://doi.org/10.3850/IAHR-39WC2521711920221094
• Public URL: https://nottingham-repository.worktribe.com/output/29273334
• Publisher URL: https://www.iahr.org/library/infor?pid=21506