Understanding and assessing volcanic hazards, scenarios, and risks in the Lesser Antilles – implications for decision-making, crisis management, and pragmatic development – CASAVA

The Lesser Antilles volcanic arc of the West Indies is the smallest volcanic region in the world with 21 live volcanoes. However it consists of 12 different countries with different socio-economic characteristics and elevated population densities, most of which concentrate near the coast as well as on the flanks of live volcanoes. This region is known worldwide for having experienced the most lethal eruption caused by a primary volcanic phenomena, and one of the worst in recorded history. On May 8 1902, a laterally-directed pyroclastic density current destroyed the town of Saint-Pierre in Martinique killing 28 000 people. An additional 3000 people perished in the town of Morne Rouge on August 30 1902. Volcanic risks will pose an increasing threat to insular populations also vulnerable to other hazards such as hurricanes, earthquakes and tsunamis. Over the last 14 years the exceptionally long-lived and on-going eruption of Soufrière Hills volcano on Montserrat has dramatically affected the island's population and fragile socio-economic equilibrium. The capital city of Plymouth has been ravaged like St. Pierre 100 years ago. The towns of Basse-Terre (Guadeloupe) and Saint-Pierre (Martinique) are exposed to volcanic hazards as was Plymouth. Soufrière of Guadeloupe and Montagne Pelée threaten up to 200 000 people directly and perhaps more than 500 000 additional people indirectly in the region incase of renewed magmatic eruptions of high magnitude that could also involve edifice collapse. Risk assessment and management are thus fundamental scientific, economic, and political issues, especially in densely populated areas. The most efficient treatment of these aspects requires accurate quantitative assessment and mitigation strategies, the development of effective tools for forecasting, prediction and management of crises and the promotion of capacity building and sustainable development within such regions. It implies that scientists, engineers, governments, civil protection agencies, communities develop synergistic activities. The geologic past of both volcanoes is well-known, the volcanoes are well-monitored,and numerous independent studies in the social sciences have improved the overall assessment of volcanic risk in Guadeloupe and Martinique. Nevertheless, a nationally-funded multidisciplinar French research project has never addressed the challenges of state-of-the-art risk quantitative assessment, crisis management and prevention in one integrated approach building on a synergy between various disciplines. In the CASAVA project (Compréhension des Aléas, Scénarios, et risques Volcaniques aux Antilles), we aim at reducing this gap by providing a state-of-the-art integrated basic research strategy for achieving quantitative volcanic risk assessments that takes into account the socio-cultural dimension and is focused on active volcanoes of the French Lesser Antilles, Soufrière of Guadeloupe and Montagne Pelée of Martinique. Building on the important corpus of lessons learnt from the study and management of the Soufrière Hills eruption, CASAVA will provide new insights into the reconstruction of the eruptive past of La Soufrière and Montagne Pelée, improved modelling of key volcanic hazards and their impact, as well as improved probabilistic tools and vulnerability assessment methodologies to address the forecasting, management, and prevention of volcanic risks from a future eruption. The CASAVA project is a multidisciplinary research project that spans the entire spectrum of disciplines and includes: earth sciences, computer and engineering science applied to simulation of volcanic phenomena, physical geography and the analysis of territorial vulnerability, social sciences and analysis of socio-cultural and human vulnerability, archeology of volcanic impact on recent pre-Colombian human occupation, legal issues of natural disasters, probabilistic decision making and risk assessment, crisis management and mitigation measures, institutional policy on risk management, the role of natural disaster insurance policy on risk management, and applied mathematics and artificial intelligence to simulate realistic eruption scenarios, impact, and population behavior.