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The monumental complex of Maredolce (Palermo) includes an Arab‐Norman castle that stands on the banks of an artificial lake carved out of the calcarenitic rock that rests on impermeable clays. The lake was originally filled with water, thanks to the channelling of a spring. Over time, the lowering of the water table and the high hydraulic permeability of the calcarenites have caused the lake to dry up. A project to renovate the monumental complex has recently been launched. It also provides the study of a possible restoration of the original conditions of the lake. To this end, a multidisciplinary geophysical study was carried out to investigate the geotechnical conditions of permeability of the land outcropping and provides valid technical solutions for waterproofing the bottom of the lake. For this purpose, a joint interpretation was performed using data acquired with different geophysical techniques, such as seismic refraction tomography, electrical resistivity and induced polarization tomography, multichannel analysis of surface waves and horizontal‐to‐vertical spectral ratio of environmental vibration recording. Joint interpretation, supported by cluster analysis techniques, allowed the reconstruction of the geophysical and geotechnical model of the subsoil of the ancient lake, helpful to suggest appropriate techniques for waterproofing the bottom of the lake. [ABSTRACT FROM AUTHOR]

Abstract: Seismic refraction, surface wave surveys and P and PS seismic reflection data were acquired and processed to derive the geological setting as well as P and S velocity profiles of the Plio–Pleistocene sediments that are filling a tectonic valley in central Italy. The results were constrained by boreholes, vertical electrical sounding and electrical resistivity tomography. The P-wave data, processed with standard processing, was allowed to detect the top of limestone 50m depth. The converted PS-wave data were processed with Asymptotic Common Conversion Point (ACCP) sort and non-hyperbolic normal move out correction. The study shows that special care must be devoted to data muting because of the low signal-to-noise ratio, which is mainly due to the high energy of the ground roll and the air wave. The stack section was the result of an iterative process. From theoretical analysis, we determined that the use of ACCP binning does not allow the reflection to be focused for all of the time windows because the ACCP approximation is correct only for depths greater than the shot-receiver offset. The joint interpretation of the direct and indirect data proved the capability of P and PS seismic reflection data of constraining the interpretation and removing the ambiguity in the reconstruction of the geological setting and the P and S profiles of the formation of an alluvial valley located in a seismic area. [ABSTRACT FROM AUTHOR]

Abstract: A geophysical study that involved different techniques was carried out with the aim to improve the knowledge of the archaeological site where the Basilica of Maxentius was founded and to discern individual covered structures (foundations). Vertical Electrical Sounding (VES), seismic refraction and Electrical Resistivity Tomography (ERT) studies were performed in the archaeological site. VES and seismic refraction allowed to characterise the main geological formations of the hill where the Basilica was built and to distinguish the concrete floor and backfilling. Electrical data were processed using different algorithms; their results were compared to appraise the inverted models'' robustness. ERT inversion algorithms were used to delineate shape and size of a much more complex structure, that were originally expected from archaeological excavation plan. The results of the commercial program were used as a posteriori information to include them in the algorithm proposed by the authors; the sequential use of the programs defined a processing procedure. The integrated use of different geophysical techniques reduced a great deal the intrinsic ambiguities of each method. Direct explorations (boreholes and archaeological excavations) confirmed the geophysical results. [Copyright &y& Elsevier]