Reservoir-induced seismicity in Brazil

A compilation of 16 cases of reservoir-induced seismicity in Brazil is presented with maximum magnitudes ranging from 1.6 M-L to 4.2 m(b). The compilation includes: location of the main epicentral area with respect to the reservoir (inside the lake, at the margin, or outside), predominant geology, and the temporal distribution of the main phase(s) of activity (initial or delayed in relation to impoundment). Data on the regional stress field for some reservoirs is also included. Four recent cases are discussed in more detail: Tucurui, Nova Ponte, Miranda, and Serra da Mesa. A comparison with all other reservoirs deeper than 30 m and 50 m suggests that the hazard for induced-seismicity varies within Brazil: the NE part of the intracratonic Parana basin has higher hazard as compared with the southern part of the same basin. No correlation of the induced hazard with variations in natural seismicity can be observed.