GPR and Geoelectical Studies in a Historical Site in Buenos Aires, Argentina, for Locating an Old Cistern

GRUNHUT, VIVIAN; MARTINELLI, PATRICIA; BONOMO, NÉSTOR; BONGIOVANNI, MARÍA VICTORIA; PINIO,A.; OSELLA, A.,

Malmo

Congreso; Near Surface Geophysics; 2017

EAGE

We performed a geophysical study in a historical site. The main objective was to localize and characterize anold water cistern, no longer in use. Considering its expected dimensions, high density GPR data andgeoelectrical dipole-dipole profiles were acquired. This allowed achieving very good resolution of thesubsurface structures.We could localize the cistern and determine that it would not be risk of collapse. While a very resistive electricalanomaly related to this structure was identified (with a diameter of approximately 1.5 m and extending up to adepth of about 0.9 m), considering the GPR results, this anomaly was associated to resistive filling material andnot to the presence of a void. Below that depth, the structure seems to be filled with compacted material similarto the surrounding soil. Two other anomalous zones were detected that could correspond to structures withhistorical lineage. Exploratory excavations are being carried out.Regarding the geoelectrical data, first, conventional 2D inversions were done. Then, a pseudo-3D model wasbuilt by transversally interpolating those results, and also a fully 3D inversion was performed. This aided tofurther improve the delineation of the anomalies.