Earthquakes in Brazil

Abstract

Earthquakes are so rare in Brazil that their very rarity is a matter of interest to geologists and seismologists. In order to give an idea of the low seismicity of that country and to facilitate the collection and preservation of data in the future I have brought together in this paper all the information it has been possible to gather from a considerable acquaintance with the literature of Brazilian geology. In January, 1909, Dr. M. A. R. Lisboa of Petropolis, a distinguished Brazilian geologist, published in the Jornal do Commercio of Rio de Janeiro a resume of Brazilian earthquakes that is the most complete list thus far printed. That paper, however, is not accessible to geologists and seismologists, and I have been able to make several additions to the list.' The table gives all the reported earthquakes in their chronological order, and one column shows the intensities by the Rossi-Forel scale as nearly as they can be judged from the accounts. The papers cited include all the known publications regarding earthquakes in Brazil. There is one important article, however, bearing upon seismology in Brazil that has not been used in constructing the table, and that is a paper containing a list of eathquake shocks reported at sea off the northeast coast of Brazil by sailing masters. That article is entitled Note sur I'existence probable d'un volcan sou-marin situ6 par environ o° 20' de latitude sud, et 220 de longitude ouest, par P. Daussy, Comptes Rendus, VI, 512-18 (Paris, 1838). In his Tremblements de Terre, Geographie Seismologique, M. Montessus de Ballore gives a chart of the region at p. 168. i. Manoel Ayres de Cazal.--Corografia Brazilica, ou relagao historico-geografica do Reino do Brazil, I, 261. Rio de Janeiro, 1817. In his description of the province of Matto Grosso the author has this note on earthquakes: On the 24th of September (1744) at noon, during clear weather, underground thunder was heard, and immediately the earth trembled, giving