## Abstract

Accurate predictions of maximum initial wave amplitude are essential for coastal impact assessment of tsunami waves generated by submarine landslides. Here, we analyse the existing predictive equations for the maximum initial amplitude (η_{max}) of submarine landslide-generated waves and study their performance in reproducing real-world landslide incidents. Existing equations include various landslide parameters such as specific gravity (γ_{s}), initial submergence (d), slide length (B), width (w), thickness (T) and slope angle (θ). To determine how landslide parameters affect wave amplitude, we conduct a systematic sensitivity analysis. Results indicate that the slide volume (V = B × w × T) and d are among the most sensitive parameters. The data from the 1994 Skagway (observed η_{max}: 1.0–2.0 m) and 1998 Papua New Guinea (PNG) (observed η_{max}: 10–16 m) incidents provided valuable benchmarks for evaluating the performance of the existing equations. The predicted maximum initial amplitudes of 0.03–686.5 m and 3.7–6746.0 m were obtained for the 1994 and 1998 events, respectively, indicating a wide range for wave amplitudes. The predicted estimates for the smaller-sized event, i.e. the 1994 Skagway, appear to be more accurate than those made for the larger event, i.e. the 1998 PNG case. We develop a new predictive equation by fitting an equation to actual submarine landslide tsunamis: ηmax=50.67(Vd)0.34, where V is the slide volume (km^{3}), d is initial submergence depth (m), and η_{max} is in metres. Our new equation gives wave amplitudes of 1.6 m and 7.8 m for the 1994 and 1998 landslide tsunamis, respectively, which are fairly consistent with real observations.

Original language | English |
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Pages (from-to) | 1591-1611 |

Number of pages | 21 |

Journal | Natural Hazards |

Volume | 103 |

Issue number | 1 |

DOIs | |

Publication status | Published - 21 May 2020 |

### Bibliographical note

Funding Information:We are grateful to Prof Alexander Rabinovich (Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, Canada) for providing the observed tide gauge waveform of the 1994 Skagway tsunami. We sincerely thank Professor James Goff (the Editor-in-Chief) and two anonymous reviewers for their constructive review comments which greatly helped to improve this article. MH is funded by the Royal Society, the United Kingdom, under Grant Number CHL\R1\180173.

Publisher Copyright:

© 2020, The Author(s).

## Keywords

- Landslide
- Landslide-generated waves
- Papua New Guinea
- Tsunami

## ASJC Scopus subject areas

- Water Science and Technology
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)