With the aim of improving our understanding of the development and potential instability of the Randazzo landslide which occurred in the months of March and April, 1996, inclinometric, piezometric and topographical data were collected and compared with the results of differential interferometric elaboration (DIFSAR), up till the end of 1998 using the data of ERS1 and ERS2 satellites, that detected displacements of 1cm a day. The elaborations enable us to individuate the morphology of the earth mass in movement, and to consider displacements detected in a short time-interval at the end of paroxysmal stage (3-4 April). They show that after the event displacements stopped, or were of such low velocity so as to be not detectable by this technology, apart from in limited areas. These results seem to be in accord with those obtained from inclinometric measurements, which show displacements all within the range of instrumental error. Recently, a DIFSAR elaboration over a period of seventy days (25 August- 4 November 1998) has revealed a clear image of the entire landslide body. Coming at the end of a particularly dry period and being associated with a discrete lowering of the water table the variations could be the combined result of a small contraction of the flowed masses (not detected by inclinometric measurements) on account of drought and/or a strong variation in the dielectric constant. In either cases the detected variations are caused by the strong difference in physical properties of the flowed masses from the surrounding areas. (C) 2000 Elsevier Science Ltd. All rights reserved.
