Análise espacial das ocorrências sísmicas e da vulnerabilidade socioambiental a sismos em Montes Claros - MG

Abstract

In Montes Claros, a city located in north of the state of Minas Gerais, it has been observed in the past few years that is happening a considerable seismic activity, geological phenomenon that already caused some minor damage in fragile houses and it is scaring the population. In this context, it is important to understand the local seismicity and to generate solid information about the seismic characteristics of Montes Claros, once there’s still a lack of technical and scientific paperson the subject. It is also important to carry out studies aimed at identifying the social and environmental areas of vulnerability to earthquakes in the city. Therefore, this paper aims to analyze the seismicity of Montes Claros, featuring seismic occurrences in terms of location, magnitude and frequency. It soughtto also, in addition, identify the areas with higher and lower presence of social and environmental vulnerability within the urban perimeter of the cityfrom the overlap of social vulnerability maps and environmental vulnerability to earthquakes. In order to achieve this objectives seismic event data that occurred in this city were sought, from instrumental registers of regional and local stations, and were made maps, charts and graphs for detailed comprehension of seismicity. Beyond that, it was elaborateda map of social and environmental vulnerability to earthquakes areas of the city. The results showed that the seismic events in Montes Claros have occurred since 1995, with, however, an intensification of tremors, both in terms of frequency and in magnitude since 2012. There was an epicentral concentration in Northwest area of the city where is located the Vila Atlântidaneighborhood and surrounding areas. It was also noted that the tremors occurred in 2014 moved away a few kilometers from the urban area of the city in north-west direction. The results showed that areas with higher social and environmental vulnerability index are located notably in the northwest region and the areas with lower index are located on the south west of the city. It is concluded that the seismicity in Montes Claros stands out for its frequency and moderate magnitude, which is aggravated by the proximity to the urban center. In addition, there are several sectors with high social and environmental vulnerability index and the effects of tremors may be significant for the population living in these areas.