Seven municipalities - Saint-Pierre, of which we see a few houses from the Observatoire Volcanologique de Morne des Cadets, but also Le Prêcheur, Morne-Rouge, Grand-Rivière, Ajoupa-Bouillon, Basse-Pointe, and Macouba - are located on the slopes of Mount Pelée, the only active volcano on the island of Martinique. They have a total population of nearly 35,000 inhabitants placed in the event of an eruption on the front line of the evacuation plan put in place by the authorities. The last magmatic eruption of Mount Pelée took place between 1929 and 1932. Since then, the activity of the volcano has decreased significantly. Its fumarolic activity has been nil since 1970, while its hydrothermal activity is slowly decreasing. As for its low seismic activity, it is linked to the circulations and interactions of gas, steam, and water under pressure in the porous and fractured rock of the mountain.