Atlantic seaquakes on 1.XI.1755 (Great Lisbon earthquake) and 31.III.1761

Abstract

The article deals with data on the seismic regime before and after the Lisbon earthquake on November 1, 1755, which was accompanied by an unusual seismic activation over a large area of Western Europe, North Africa and the Atlantic, which is practically not reflected in the scientific literature. After November 1, 1755, the seismic series was observed in Western Europe, which cannot be attributed to the typical aftershock process. A distinctive feature of the post-Lisbon three phase-activ ation was the occurrence of ea rthquakes, sometimes simultaneously, in separated isolated regions of Europe, far beyond the aftershock area manifestation. In the post Lisbon seismic scenario an important and underestimated value is occupied by the earthquake of March 31, 1761, which can be considered as a “twin” of the Great Lisbon catastrophe on November 1, 1755. Both earthquakes were generated in the western Atlantic, therefore it is more correct to call them seaquakes.