A study, and field survey on the island of Guadeloupe, have concluded that the magnitude 6.3 earthquake of November 21, 2004 near Dominica and Guadeloupe generated a weak tsunami with runup not exceeding 0.7 meters or 28 inches.
This event constitutes at least the seventh tsunami documented in the Guadeloupe-Dominica area. The earthquake was remarkably destructive, notably in Terre-de-Bas but some damage was sustained in Dominica and Guadeloupe. While the tsunami amplitudes remained minimal, this earthquake serves to emphasize the constant tsunami risk in the area, notably in view of the numerous landslides triggered by the seismic event.
Village of Trois-Rivières: One person (a 5-year old girl) was killed, at least two other injured, and several houses destroyed or damaged. In the port, one fisherman reported that his boat dropped down about 50 cm during the earthquake and then rose back; he was afraid his boat could hit the sea bottom and tip over.
Marina de Rivière Sens (city of Basse-Terre): One witness informed the study group that the water dropped down a few cm and then rose back during the earthquake.
Island of Terre-de-Bas, Les Saintes:
Village of Grande Anse, Bay “Anse des Muriers”. A ship captain reported that 3 minutes after the earthquake, the sea receded 5 m (and dropped 80 cm) and rose back to its still level, over perhaps 1 minute.
Beach of Grande Anse. A restaurant owner reported that the tsunami began as an ebbing phase, and then a positive wave reached a house on the beach; this run-up was surveyed as 70 cm.
Village of Petites Anses. At least eight houses were destroyed and twenty-five damaged in this village. At the small bay “Anse à Dos”, a fisherman said that water receded a distance of 2 to 3 m just after the earthquake, and then rose back to normal level.
Dominica:
(Reported to survey team by Public Seismic Network Inc., Dominica).Ten to twenty minutes after the main 6.3 shock, credible witnesses including a retired high-school teacher and a younger high-school teacher reported a significant drawing back of the sea in the Portsmouth harbour leaving fish stranded. The younger of the two even entered the area where the sea drew back and started throwing fish back into the withdrawn sea before he was beckoned to get out as there may be a possible danger of tsunami.
Photos show buildings damaged by earthquake in Guadeloupe, Terre-de-Bas and Dominica and entry in international tsunami database.
(Zahibo N. et al)