The Caribbean Sea countries are often affected by various marine natural hazards: hurricanes and cyclones, tsunamis and flooding. The historical data of marine natural hazards for the Lesser Antilles and specially, for Guadeloupe are presented briefly. Numerical simulation of several historical tsunamis in the Caribbean Sea (1755 Lisbon trans-Atlantic tsunami, 1867 Virgin Island earthquake tsunami, 2003 Montserrat volcano tsunami) are performed within the framework of the nonlinear-shallow theory. Numerical results demonstrate the importance of the real bathymetry variability with respect to the direction of propagation of tsunami wave and its characteristics. The prognostic tsunami wave height distribution along the Caribbean Coast is computed using various forms of seismic and hydrodynamics sources. These results are used to estimate the far-field potential for tsunami hazards at coastal locations in the Caribbean Sea. The nonlinear shallow-water theory is also applied to model storm surges induced by tropical cyclones, in particular, cyclones “Lilli” in 2002 and “Dean” in 2007. Obtained results are compared with observed data. The numerical models have been tested against known analytical solutions of the nonlinear shallow-water wave equations. Obtained results are described in details in [1-7].
The strong earthquake (M = 6.3) occurred on 21st November 2004 in the DominicaPassage, between Guadeloupe and Dominica (Lesser Antilles), generated aweak tsunami with maximum amplitude 80 cm on neighbouring islands. Field surveyis conducted on November 27, 2004. Data of the field survey are described. Results ofthe numerical simulations in the framework of the shallow-water theory are in reasonableagreement with observed data.
The problem of long-wave scattering by piecewise-constant periodic topography is studied both for a linear solitary-like wave pulse, and for a weakly nonlinear solitary wave [Korteweg–de Vries (KdV) soliton]. If the characteristic length of the topographic irregularities is larger than the pulse length, the solution of the scattering problem is obtained analytically for a leading wave in the framework of linear shallow-water theory. The wave decrement in the case of the small height of the topographic irregularities is proportional to δ2, where δ is the relative height of the topographic obstacles. An analytical approximate solution is also obtained for the weakly nonlinear problem when the length of the irregularities is larger than the characteristic nonlinear length scale. In this case, the Korteweg–de Vries equation is solved for each piece of constant depth by using the inverse scattering technique; the solutions are matched at each step by using linear shallow-water theory. The weakly nonlinear solitary wave decays more significantly than the linear solitary pulse. Solitary wave dynamics above a random seabed is also discussed, and the results obtained for random topography (including experimental data) are in reasonable agreement with the calculations for piecewise topography.
<p>Tropical cyclones can be considered one type of extreme event, with their destructive winds, torrential rainfall and storm surge. Every year these natural phenomena affect millions of people around the world, leaving a trail of destruction in several countries, especially along the coastal areas. Only in 2017, two devastating major hurricanes (Irma and Maria) moved across the Caribbean and south-eastern USA, causing extensive damage and deaths. Irma formed in the far eastern Atlantic Ocean on 30 August 2017 and moved towards the Caribbean islands during the following week, significantly strengthening, becoming a Category 5 Hurricane. It caused wide-ranging impacts such as significant storm surge (up to 3m according to US National Oceanic and Atmospheric Administration, NOAA report) to several islands in the Caribbean and Florida. On the second half of September, 2017, another strong Category 5 Hurricane named Maria formed over the Atlantic and moved west towards the Caribbean Sea. Maria also caused several impacts and severe damage in Caribbean Islands, Puerto Rico and the U.S. Virgin Islands due to high speed winds, rainfall, flooding and storm surge with a maximum runup of 3.7 m (US NOAA) on the southern tip of Dominica Island. The most recent devastating event for the Atlantic is Hurricane Dorian. It formed on August 24, 2019 over the Atlantic Ocean and it moved towards the Caribbean islands, as getting stronger as moving, becoming a Category 5 before reaching the Bahamas, where it left a trail of destruction after its passage. The major effect of Dorian was on north-western Bahamas with very strong winds, heavy rainfall and a large storm surge.</p><p>In this context, a rapid and reliable modeling of storm surge generated by such kind of events is essential for many purposes such as early accurate assessment of the situation, forecasting, estimation of potential impact in coastal areas, and operational issues like emergency management.</p><p>A numerical model, NAMI DANCE GPU T-SS (Tsunami-Storm Surge) is developed building up on tsunami numerical model NAMI DANCE GPU version to solve nonlinear shallow water equations, using the pressure and wind fields as inputs to compute spatial and temporal distribution of water level throughout the study domain and respective inundation related to tropical cyclones, based on the equations used in the HyFlux2 Code developed by the Joint Research Centre of the European Commission. The code provides a rapid calculation since it is structured for Graphical Processing Unit (GPU) using CUDA API.</p><p>NAMI DANCE GPU T-SS has been applied to many cases as regular shaped basins under circular static and dynamic pressure fields separately and also different wind fields for validation together with combinations of pressure and wind fields. This study has been conducted to investigate the potential of numerical modeling of tropical cyclone generated storm surge based on recent events Irma, Maria and Dorian. The results are presented and discussed based on comparison with the measurements and observations. The study shows promise for developing a cyclone modeling capability based on available measurement and observational data.</p>
Results of the numerical modeling of potential tsunamis generated in the center of the Caribbean Sea are given.Numerical modeling is performed with the use of TUNAMI N3 and NAMI DANCE.The maximum amplitude of the water elevation in Lesser Antilles can reach upto 3-4m.The travel time of tsunami is 1.5 hours to Northern islands of Lesser Antilles and 2 hours to Southern islands of Lesser Antilles.It must also be noted that the southern coast of Caribbean Sea will be much more effected comparing to the Lesser Antilles when a tsunami is generated in the center of the Caribbean Sea.
Tsunamis are among the most deadliest threat of coastal areas and a large number of tropical island are exposed because of their proximity to potential tsunami sources.However, far field sources may represent a threat and thus can not totally be eluded.In the framework of the project C3AF which studies the consequences of climate changes over the French West Indies, we used the numerical model SCHISM (ZHANG et al., 2016) to simulate several potential tsunamis propagation as well as their impacts over the Guadeloupe Island (French West Indies).In this study, we present the simulation of a potential tsunami scenario based on the collapse of the Cumbre Viera volcano, in the Canary Islands (ABADIE et al., 2012) to assess the potential threat of the Guadeloupe archipelago.Several scenario have been simulated and time arrival, wave heights and potential inundation are investigated.
Abstract. In the Lesser Antilles, coastal inundations from hurricane-induced storm surges pose a great threat to lives, properties and ecosystems. Assessing current and future storm surge hazards with sufficient spatial resolution is of primary interest to help coastal planners and decision makers develop mitigation and adaptation measures. Here, we use wave–current numerical models and statistical methods to investigate worst case scenarios and 100-year surge levels for the case study of Martinique under present climate or considering a potential sea level rise. Results confirm that the wave setup plays a major role in the Lesser Antilles, where the narrow island shelf impedes the piling-up of large amounts of wind-driven water on the shoreline during extreme events. The radiation stress gradients thus contribute significantly to the total surge – up to 100 % in some cases. The nonlinear interactions of sea level rise (SLR) with bathymetry and topography are generally found to be relatively small in Martinique but can reach several tens of centimeters in low-lying areas where the inundation extent is strongly enhanced compared to present conditions. These findings further emphasize the importance of waves for developing operational storm surge warning systems in the Lesser Antilles and encourage caution when using static methods to assess the impact of sea level rise on storm surge hazard.
The present study examines the propagation of tsunami waves generated by the 1755 Lisbon earthquake in the Atlantic Ocean and its effects on the coasts of the French West Indies in the Caribbean Sea.Historical data of tsunami manifestation in the French West Indies are briefly reproduced.The mathematical model named NAMI DANCE which solves the shallow-water equations has been applied in the computations.Three possible seismic source alternatives are selected for 1755 event in the simulations.The results obtained from the simulations demonstrate that the directivity of tsunami energy is divided into two strong beams directed to the southern part of North America (Florida, the Bahamas) and to the northern part of South America (Brazil).The tsunami waves reach the Lesser Antilles in 7 hrs.The computed distribution of tsunami wave height along the coasts of Guadeloupe and Martinique are presented.Calculated maximum wave amplitudes reached 2 m in Guadeloupe and 1.5 m in Martinique.These results are also in agreement with observed data (1.8-3 m).The experience and data obtained in this study show that transatlantic events must also be considered in the tsunami hazard assessment and development of mitigation strategies for the French West Indies.
Parametric cyclonic wind fields are widely used worldwide for insurance risk underwriting, coastal planning, and storm surge forecasts. They support high-stakes financial, development and emergency decisions. Yet, there is still no consensus on a potentially “best” parametric approach, nor guidance to choose among the great variety of published models. The aim of this paper is to demonstrate that recent progress in estimating extreme surface wind speeds from satellite remote sensing now makes it possible to assess the performance of existing parametric models, and select a relevant one with greater objectivity. In particular, we show that the Cyclone Global Navigation Satellite System (CYGNSS) mission of NASA, along with the Advanced Scatterometer (ASCAT), are able to capture a substantial part of the tropical cyclone structure, and to aid in characterizing the strengths and weaknesses of a number of parametric models. Our results suggest that none of the traditional empirical approaches are the best option in all cases. Rather, the choice of a parametric model depends on several criteria, such as cyclone intensity and the availability of wind radii information. The benefit of using satellite remote sensing data to select a relevant parametric model for a specific case study is tested here by simulating hurricane Maria (2017). The significant wave heights computed by a wave-current hydrodynamic coupled model are found to be in good agreement with the predictions given by the remote sensing data. The results and approach presented in this study should shed new light on how to handle parametric cyclonic wind models, and help the scientific community conduct better wind, wave, and surge analyses for tropical cyclones.
