A tsunami deposit at Anse Meunier, Martinique Island: Evidence of the 1755 CE Lisbon tsunami and implication for hazard assessment

Abstract

This study presents the results of paleo-tsunami investigation in marshes of the southern and eastern coasts of Martinique Island (Lesser Antilles, France). A sand unit dated 1726–1813 cal. CE at 30 cm depth at Anse Meunier represents the most convincing evidence of high-energy coastal flooding of the last 5000 years on the island. Sedimentological analyses combined with tsunami simulations demonstrate that this sand deposit likely corresponds to the 1755 CE Lisbon transatlantic tsunami. No other tsunami or hurricane event was identified on the 11 marshes investigated. The 1755 Lisbon tsunami is thus the only tsunami recorded in the stratigraphy of coastal marshes of the southern and eastern coasts of Martinique Island during the last 3500 years, even if we cannot exclude the possibility of larger-magnitude but lower-frequency tsunamis that would not be recorded in coastal stratigraphy during this period.