A violent earthquake of intensity XI on the Modified Mecalli Intensity (MMI) scale occurred in the morning of November 1, 1755, the All Saints Day Catholic holiday, near the Gorringe Bank off the Iberian Coast near Lisbon, Portugal. The earthquake generated a destructive tsunami that affected the coast of Portugal, Spain, North Africa, and the Caribbean.

The tsunami wave reached Lisbon about 40 minutes after the first destructive shock and surged up to 18 meters in some places near Lisbon. At Azores the wave height was up to 15 meters. In 9.3 hours the tsunami arrived to Saba, Netherland Antilles having 6.4 m in height. The total number of fatalities in Portugal is estimated to be 60,000. It is difficult to resolve what part of them was due to tsunami, but we can assume that it is at least half of the total that gives the estimated 30,000 victims. The Moroccan Atlantic coast was struck by 15-m waves at a cost of 9,000 - 11,000 lives (O'Loughlin, Lander, 2003). There is no quantitative data on tsunami victims in the Caribbean islands, but taking into account the reported run-up height (from 6 to 8 meters) there should be at least some.

Image shows Tsunami travel time chart for the 1755 Lisbon tsunami. Solid ellipse marks position of the earthquake source. Red color shows the area within 1-hour propagation time. Digits near the isochrones - propagation time in hours. Digits in bold show the reported fatalities, digits in italic - maximum reported run-up within the particular tsunami travel time interval.