Reanalysis of the 1761 transatlantic tsunami
The tsunami catalogues of the Atlantic include two transatlantic tsunamis in the 18th century the extensively studied 1st November 1755, and 31st March 1761. The latest event struck Portugal, Spain, and Morocco around noontime. Several sources report a tsunami following the earthquake as far as Cornwall (United Kingdom), Cork (Ireland) and Barbados (Caribbean). An earlier analysis of macroseismic information and its compatibility with tsunami travel time information located the epicentre circa 34.5° N 13° W close to the Ampere Seamount at the eastern end of the Gloria Fault (North East Atlantic). The estimated magnitude of the earthquake is 8.5. In this study, we propose a tectonic source for the 31st March 1761 earthquake compatible with the tsunami observations in the Atlantic.