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portuguesA crescente urbanizacao sobre o solo espesso e pouco coeso do Distrito Federal (DF) – Brasil, aumentou a vulnerabilidade da area aos riscos naturais, especialmente a erosao do solo e movimento de massa. Este estudo preliminar aplicou tecnicas de geofisica baseadas em ruido, como a densidade espectral de potencia (PSD), relacao espectral horizontal a vertical (HVSR), analise multicanal de ondas de superficie (MASW) e interferometria de ruido para um movimento de massa em Brasilia para a compreensao de processos geodinâmicos que atuam na ocorrencia destes acidentes. Os resultados obtidos aqui mostram um pico estratigrafico uniforme a 2 Hz observado em todas as curvas de HVSR, uma secao de onda de cisalhamento em quatro camadas foi obtida por MASW. A curva de dispersao (frequencia vs velocidade de fase) mostra as primeria e segunda modas fundamentais em frequencias de 5 e 25 Hz, respectivamente. Os correlogramas de ruido mostram atrasos de tempo maiores que + - 0,5 seg nas formas de onda da componente ZR (vertical-radial), principalmente na parte acausal. As mudancas de velocidade relativa calculadas pela tecnica de alongamento mostram tendencias anomalas em resposta a eventos pluviometricos. A sequencia da pesquisa incidira na deteccao de possiveis mudancas nos registros de ruido no movimento de massa, principalmente relacionadas a fatores desencadeantes naturais (erosao de chuva e de rio) em condicoes de dados mais controladas EnglishEver increasing urbanization over the thick and less cohesive soil of the Federal District (DF) – Brazil, has increased area's vulnerability to natural hazards, especially the soil erosion and mass movement. This preliminarily study applied noise based geophysical techniques like power spectral density (PSD), horizontal to vertical spectral ratio (HVSR), multichannel analysis of surface waves (MASW) and noise interferometry to a mass movement in Brasilia for the understating of geodynamic processes working in the background of these hazards. Here obtained results show a uniform stratigraphic peak at 2 Hz observed on all HVSR curves, a four layered shear wave section was obtained by MASW. Dispersion curve (frequency vs phase velocity) shows first and second fundamental modes at frequencies of 5 and 25 Hz, respectively. Noise correlograms show time delay larger than +- 0.5 sec on the waveforms of ZR (vertical-radial) component, mainly in acausal part. Relative velocity changes calculated by stretching technique show anomalous trends in response to rainfall events. Follow research will focus on the detection of possible changes in noise records within mass movement mainly related to natural triggering factors (rainfall and river erosion) under more controlled data conditions

ANALYSIS OF SURFACE WAVES RECORDED AT A MASS MOVEMENT IN BRASÍLIA, BRAZIL: AN IMPLICATION IN HAZARD MITIGATION