GPR application for the characterization of sinkholes in Teresina, Brazil

The town of Teresina, in the state Piauí, Brazil, presents a history land sinking processes. Two events deserve to be highlighted, first occurred 1999 at Simplício Mendes Street and other on July 31, 2008, Francisco Street. To identify possible shallow caves associated structures, Geological Survey Brazil/CPRM developed Ground Penetrating Radar (GPR) study verify occurrence reflection patterns characteristic these dissolution structures. In field, team conducted GPR sections along streets with collapse. results obtained shielded antennas 200 MHz allowed identification old areas collapse terrain, maximum depth 3 m. addition, by this show potential applying method characterization subsoil paved streets, making it various layers: asphalt, actual pavement, subgrade soil, saprolite, mixed material. high clay content does not allow investigate further depths research area. interpretation aero-magnetometric data shows that sinkholes is magnetic lineaments mainly NW–SE direction enhances understanding structural framework