Publication Date:
2012-01-21
Description:
The 16 October 1979 landslide at Nice airport, France, produced tsunami waves observed in several harbors, and the city of Antibes was significantly flooded. A new simulation of this event is presented in this paper to assess the sensitivity of the tsunami to the properties of the slide and to evaluate how local bathymetry and harbor resonance influence the effects of the tsunami at the coast. A study of slide viscosity and water incorporation is performed using a detailed numerical model with a single initial volume of about 107 m3. The propagation of the tsunami is then simulated with a multigrid finite difference code, using high-resolution bathymetry in the harbors, to a greater level of detail than previous studies. We show that while the slide parameters are of great importance to properly model the later stages of the slide, the initial volume and early dynamics of the slide are the relevant factors for determining the characteristics of the tsunami. Numerical results are compared with tide recordings in Nice and Villefranche, as well as a mapping of the flood. Computed maximum elevation maps are compared with witness reports, highlighting a focusing of the waves on Antibes, which explains its vulnerability. This kind of focusing pattern should be considered when assessing the tsunami hazard for coastal regions. Calculated resonant periods in Nice, Villefranche, Port Vauban, and La Salis are matched with components present in both observed and computed waveforms. Most of the observed waves in Nice and Villefranche can be attributed to resonance.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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