Urban subsidence as a local response of Amazonas river flooding observed by satellite SAR interferometry

The application of Interferometric Synthetic Aperture Radar (InSAR) for detecting terrain deformation in the Amazon region is an important research tool that allows high accuracy of geophysical models based on satellite data. Amazonian forest cover and climate regime make InSAR implementation very difficult, so literature about the subject in that region is still rare. In this paper, we apply the interferometric technique to a stack of 24 Radarsat-2 images acquired from 2008 to 2010 over Manaus city (Amazonas state, Brazil) aiming to understand the terrain movement in the urban area, which has been detected by previous studies using Radarsat-1 data. The observed subsidence is estimated to be about three centimeters and occurs in the vicinities of the international airport. The phenomena can be associated with the Amazonas river flooding system, and indicates a local response from the seasonal fluctuations and Earth́s elasticity.