Rainfall-induced variations in pore water pressures are the most common sources of significant disasters involving soils like landslides and structural collap-ses of man-made infrastructures. This study aimed at communicating preliminary results of seasonal monitoring of the Sobradinho landslide, Brasilia, Brazil, using ambient seismic noise. The noise was recorded before, during and after the rainy season with three L4-3A seismometers (2Hz) installed in a triangular array within the landslide mass. These records were processed using horizontal to vertical spectral ratio (HVSR) technique. As it is resulted from the performed analyses, two frequency (ubiquitous (2Hz) and iniquitous (>2Hz)) peaks were observed over HVSR curves. The fluctuations in the secondary peak of HVSR curves are possibly related to changes in soil properties of landslide mass (i.e. saturation, water content, consistence) in response to seasonal meteorological conditions. Experiments with a denser observation system are required to validate such a behavior. The proposed method can be used for the monitoring of landslides as well as civil engineering structures like dams, enbankments, backfills.
