A Twin of the Great Lisbon Earthquake (Based on Materials from the Newspaper Sankt-Peterburgskie vedomosti for the 18th Century)

Abstract

The article generalizes materials on the earthquake of March 31, 1761, which is almost unknown in our scientific discourse, although very significant in its seismological impacts; it can therefore be considered as a twin of the Great Lisbon disaster of November 1, 1755. The 1761 earthquake struck a large part of Europe and, although it did not involve such disastrous consequences as the 1755 Lisbon quake, it significantly changed the seismic regime observed after after the latter. Both earthquakes were followed by tsunamis on the western margins of Europe and the eastern coasts of North America; they also triggered seismic activations of vast, spatially different regions in Western Europe and North Africa. It is possible to associate a number of strongest seismic events in the West Atlantic region with the 1761 earthquake. In the recent research literature on the topic, predominantly by Portuguese authors, the sources of both earthquakes are located in the eastern part of the Azores–Gibraltar Transform Fault. It is of particular interest that the initial data for this article were taken from the newspaper Sankt-Petersburgskie vedomosti for the 18th century and were supplemented with information from historical catalogs and recent foreign papers.