Meteotsunamis in Brazil: an overview of known occurrences from 1977 to 2020

From 1977 to March 2020, eight atmospherically induced tsunami-like events have been observed in Brazil. Six of them occurred in the southern region of the country, where the atmosphere tends to be more unstable due to the passage of low-pressure systems, which often move from the south to the north along the coast. This trajectory combined with the shallow continental shelf in the region can favor the occurrence of resonance and, consequently, the amplification of the waves. Most events resulted only in material losses, sometimes severe, but at least one fatal victim was registered. On the vast majority of the occasions, seven in eight, the tsunami-like waves happened on the open coast, and half of them under bad-weather situations. The sparse tide gauge network and its low sampling frequency surely prevented them from being recorded, and mostly the only references about these events came only from the media.