Atividade Sísmica Em Pedra Preta-RN Em 2010

In this study, the earthquake events from the seismic activity in Pedra Preta area, Potiguar Basin border in northeastern Brazil, were analyzed. This area is one of the most active seismic areas in Brazil. The activity began on December 04, 2010, when a 3.1 mb earthquake occurred. After this event, a network with nine short period stations was installed on December 9, 2010. In this study, we analyze events between December 9 and December 27, 2010. The epicentral location was determined with the HYPO71<br>program, and the composite focal mechanism was obtained based on visual inspection of the focal sphere aided by the hypocentral location. The fault plane direction and dip was determined by distribution of the hypocenters. The epicentral location showed that there is no correlation between the seismic activity in the area and mapped geological structures. This new seismologenic fault was named as Cabeço Preto Fault. The estimated fault parameters are the following: 238° strike, 78 ° dip and -70° rake. This means that the fault in question is a normal fault.