Elaboração de catálogo sísmico para a região Nordeste do Brasil do ano de 2018

Abstract

The objective of this work is to prepare a seismic catalog for the Northeast region of Brazil in 2018, thereby monitoring seismic activity in the Northeast region, expanding the LabSis database and contributing to a better understanding of the occurrence of tremors in the region. region. A seismic catalog is composed of the epicentral coordinates, time of origin, depth and local magnitude of events. LabSis/UFRN routinely monitors seismic activity in the Northeast region of Brazil, one of the areas with the greatest seismic activity in the country. Monitoring is carried out through a permanent network of 21 broadband seismographs. To analyze the seismic data, obtain the hypocentral location and calculate the local magnitude of the events in this work, the SEISAN software was used. 3882 seismic events were identified, of which 3466 are local events, 109 are regional events and 307 are distant events. Of the 3466 local seismic events, 580 were located. The largest number of events identified was recorded at the twentieth hour of the day (UTC), with a total of 97 seismic events, possibly related to human activity carried out in the region. Between 0 and 1 km, 528 seismic events occurred, that is, more than 90% of localized events. Between 1.1 and 2 km, 2.1 and 5 km, 5.1 and 12 km and depths greater than 12 km, 16, 18, 10 and 8 events occurred, respectively. The local magnitude of localized events varied between -0.4 to 1.8 Ml.