Análise Multitemporal da Cobertura Vegetal de São Gabriel do Oeste, MS

A constante modificação do meio ambiente pelo homem tem se imposto como uma barreira à preservação dos recursos naturais. Neste contexto, estudos da dinâmica de paisagem podem permitir a compreensão das modificações ocorridas em uma região e subsidiar a criação de medidas de recuperação ambiental. Esse trabalho teve como objetivo realizar a análise multitemporal da cobertura vegetal do Município de São Gabriel do Oeste, Mato Grosso do Sul, região que abriga diversas nascentes de importantes rios do bioma Pantanal. Utilizando-se a classificação automática de imagens LANDSAT TM foi identificada a cobertura do solo de 1985 e de 2011, um intervalo de mais de 20 anos, com a realização de testes de acurácia e controle de campo, além do apoio de imagens ALOS (AVNIR-2) na atualização dos dados de uso e cobertura do solo de 2011. As classes espectrais de cobertura do solo e áreas de treinamento utilizadas na classificação foram relacionadas com as fitofisionomias propostas por Ribeiro & Walter (1998). Os resultados alcançados mostraram a cobertura de solo da região constituída por 29,25% de vegetação nativa em 1985 e 25,14% em 2011, apresentando uma redução de 4,11%

The 2009 earthquake, magnitude mb 4.8, in the Pantanal Wetlands, west-central Brazil

The main goal of this paper is to characterize the Coxim earthquake occurred in June 15th, 2009 in the Pantanal Basin and to discuss the relationship between its faulting mechanism with the Transbrasiliano Lineament. The earthquake had maximum intensity MM V causing damage in farm houses and was felt in several cities located around, including Campo Grande and Goiânia. The event had an mb 4.8 magnitude and depth was 6 km, i.e., it occurred in the upper crust, within the basement and 5 km below the Cenozoic sedimentary cover. The mechanism, a thrust fault mechanism with lateral motion, was obtained by P-wave first-motion polarities and confirmed by regional waveform modelling. The two nodal planes have orientations (strike/dip) of 300°/55° and 180°/55° and the orientation of the P-axis is approximately NE-SW. The results are similar to the Pantanal earthquake of 1964 with mb 5.4 and NE-SW compressional axis. Both events show that Pantanal Basin is a seismically active area, under compressional stress. The focal mechanism of the 1964 and 2009 events have no nodal plane that could be directly associated with the main SW-NE trending Transbrasiliano system indicating that a direct link of the Transbrasiliano with the seismicity in the Pantanal Basin is improbable

The 2009 earthquake, magnitude mb 4.8, in the Pantanal Wetlands, west-central Brazil

ABSTRACT The main goal of this paper is to characterize the Coxim earthquake occurred in June 15th, 2009 in the Pantanal Basin and to discuss the relationship between its faulting mechanism with the Transbrasiliano Lineament. The earthquake had maximum intensity MM V causing damage in farm houses and was felt in several cities located around, including Campo Grande and Goiânia. The event had an mb 4.8 magnitude and depth was 6 km, i.e., it occurred in the upper crust, within the basement and 5 km below the Cenozoic sedimentary cover. The mechanism, a thrust fault mechanism with lateral motion, was obtained by P-wave first-motion polarities and confirmed by regional waveform modelling. The two nodal planes have orientations (strike/dip) of 300°/55° and 180°/55° and the orientation of the P-axis is approximately NE-SW. The results are similar to the Pantanal earthquake of 1964 with mb 5.4 and NE-SW compressional axis. Both events show that Pantanal Basin is a seismically active area, under compressional stress. The focal mechanism of the 1964 and 2009 events have no nodal plane that could be directly associated with the main SW-NE trending Transbrasiliano system indicating that a direct link of the Transbrasiliano with the seismicity in the Pantanal Basin is improbable