HVSR, MASW, SPD, Noise Interferometry, Empirical Green Function
Resumo
Ever 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.
Biografia do Autor
Yawar HUSSAIN, University of Brasilia
Author has finished his masters and masters of philosophy degrees in applied geophysics.
Currently I am a PhD student at UnB working on: Seismoacoustic emissions of tropical clays under variable loading conditions by numerical simulation, Nanoseismic Monitoring and Noise Interferometry. An application of Geophysical methods for a Geotechnical problem
