Strongly nonlinear steepening of long interfacial waves

International audienceThe transformation of nonlinear long internal waves in a two-layer fluid is studied in the Boussinesq and rigid-lid approximation. Explicit analytic formulation of the evolution equation in terms of the Riemann invariants allows us to obtain analytical results characterizing strongly nonlinear wave steepening, including the spectral evolution. Effects manifesting the action of high nonlinear corrections of the model are highlighted. It is shown, in particular, that the breaking points on the wave profile may shift from the zero-crossing level. The wave steepening happens in a different way if the density jump is placed near the middle of the water bulk: then the wave deformation is almost symmetrical and two phases appear where the wave breaks

The 1867 Virgin Island Tsunami

International audienceThe 1867 Virgin Island Tsunami reached large magnitude on the coasts of the Caribbean Islands. A maximum tsunami height of 10 m was reported for two coastal locations (Deshaies and Sainte-Rose) in Guadeloupe. Modelling of the 1867 tsunami is performed in the framework of the nonlinear shallow-water theory. The directivity of the tsunami wave source in the Caribbean Sea according to the assumed initial waveform is investigated. The tsunami records at the several coastal regions in the Lesser Antilles, Virgin Islands, Puerto Rico and South America are simulated. The comparison between the computed and observed data is in reasonable agreement

Evaluation of tsunami risk in the Lesser Antilles

International audienceThe main goal of this study is to give the preliminary estimates of the tsunami risks for the Lesser Antilles. We investigated the available data of the tsunamis in the French West Indies using the historical data and catalogue of the tsunamis in the Lesser Antilles. In total, twenty-four (24) tsunamis were recorded in this area for last 400 years; sixteen (16) events of the seismic origin, five (5) events of volcanic origin and three (3) events of unknown source. Most of the tsunamigenic earthquakes (13) occurred in the Caribbean, and three tsunamis were generated during far away earthquakes (near the coasts of Portugal and Costa Rica). The estimates of tsunami risk are based on a preliminary analysis of the seismicity of the Caribbean area and the historical data of tsunamis. In particular, we investigate the occurrence of historical extreme runup tsunami data on Guadeloupe, and these data are revised after a survey in Guadeloupe

La réserve naturelle de Petite-Terre (Guadeloupe) : entre enjeux et vulnérabilité face aux aléas submersion marine

Since the tropical hurricane Hugo devastated Guadeloupe Archipelago in 1989, the island is more or less prepared to face another cyclonic event (alerts, shelters, etc.). On the other hand, tsunamis have only become a great concern in the Caribbean and more particularly in Guadeloupe for a couple of years (after the 2004 Indian Ocean tsunami, the 2010 Haiti earthquake and the 2011 Japan tsunami). Thus research projects have been led to try to assess marine submersion hazards as the INTERREG IV TSUNAHOULE project in which this study of the natural sanctuary of Petite-Terre has been done. Through 3 extreme scenarios chosen in agreement with meteorological and geological knowledge in the region, the modeled impact of a tsunami, a long period north swell, and a 4-5 category hurricane are presented and discussed separately after having detailed the different stakes of the sanctuary, which leads to start on thought about the vulnerability of its inhabitants, temporary or not, in front of those natural hazards

Tsunami hazard assessment of Guadeloupe Island (F.W.I.) related to a megathrust rupture on the Lesser Antilles subduction interface

International audienc

La réserve naturelle de Petite-Terre (Guadeloupe) : entre enjeux et vulnérabilité face aux aléas submersion marine

Since the tropical hurricane Hugo devastated Guadeloupe Archipelago in 1989, the island is more or less prepared to face another cyclonic event (alerts, shelters, etc.). On the other hand, tsunamis have only become a great concern in the Caribbean and more particularly in Guadeloupe for a couple of years (after the 2004 Indian Ocean tsunami, the 2010 Haiti earthquake and the 2011 Japan tsunami). Thus research projects have been led to try to assess marine submersion hazards as the INTERREG IV TSUNAHOULE project in which this study of the natural sanctuary of Petite-Terre has been done. Through 3 extreme scenarios chosen in agreement with meteorological and geological knowledge in the region, the modeled impact of a tsunami, a long period north swell, and a 4-5 category hurricane are presented and discussed separately after having detailed the different stakes of the sanctuary, which leads to start on thought about the vulnerability of its inhabitants, temporary or not, in front of those natural hazards

Discussion about tsunami interaction with fringing coral reef, in: Tsunami events and lessons learned; Advances in Natural and Technological Hazards Research, 2014, 35, 161-176.

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