Search results for "Seismic refraction"
showing 10 items of 19 documents
Joint interpretation of seismic refraction tomography and electrical resistivity tomography by cluster analysis to detect buried cavities
2020
Abstract In the last few years, the geophysical methods of seismic refraction tomography (SRT) and electrical resistivity tomography (ERT) are among the most used geophysical techniques for the reconstruction of subsoil geometries, for the investigation of underground cavities and also for the archaeological prospecting. However, the main disadvantage of each geophysical method is the difficulty of final interpretation of the data. In order to eliminate artifacts and generally improve the reliability and accuracy of geophysical interpretation, it is useful to perform a joint approach of different geophysical methods, also introducing the a priori information. In this work, it is shown the i…
The marine activities performed within the TOMO-ETNA experiment
2016
<p>The TOMO-ETNA experiment was planned in order to obtain a detailed geological and structural model of the continental and oceanic crust beneath Mt. Etna volcano and northeastern Sicily up to the Aeolian Islands (southern Italy), by integrating data from active and passive refraction and reflection seismic methodologies, magnetic and gravity surveys. This paper focuses on the marine activities performed within the experiment, which have been carried out in the Ionian and Tyrrhenian Seas, during three multidisciplinary oceanographic cruises, involving three research vessels (“Sarmiento de Gamboa”, “Galatea” and “Aegaeo”) belonging to different countries and institutions. During the o…
Joint interpretation of electrical and seismic data aimed at modelling the foundation soils of the Maredolce monumental complex in Palermo (Italy)
2020
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 o…
Gravity modelling of the lower crust in Sardinia (Italy)
1997
In this paper an example is given of an application of statistical techniques to the Bouguer anomalies analysis in order to design a simple crustal model using few a priori assumptions. All gravity measurements carried out in Sardinia have been collected and processed. The Bouguer anomalies have been calculated according to local density estimates. Spectral analysis of the Bouguer anomalies has been carried out along selected profiles in order to estimate the mean depth of the Moho discontinuity and that of an infracrustal discontinuity. The use of this technique inferred the presence of a discontinuity at a mean depth of ~ 28 km, interpreted as Moho and the likely presence of an infracrust…
Coseismic Damage at an Archaeological Site in Sicily, Italy: Evidence of Roman Age Earthquake Surface Faulting
2018
Archaeoseismology can provide a useful chronological tool for constraining earthquakes and documenting significant evidence that would otherwise be lost. In this paper, we report a case of surface faulting on ancient man-made structures belonging to the archaeological site of Santa Venera al Pozzo situated along the eastern flank of Mt. Etna volcano in eastern Sicily (southern Italy), which is affected by well-developed tectonic faults. Geological surveys highlight a set of fractures affecting the archaeological ruins, suggesting the occurrence of a capable fault zone across the area. An integrated geophysical survey was carried out in order to identify the main subsurface tectonic disconti…
Geophysical and geotechnical investigations to support the restoration project of the Roman ‘Villa del Casale’, Piazza Armerina, Sicily, Italy
2011
A multidisciplinary geophysical and geotechnical study, including some non-invasive geophysical applications, was carried out during the restoration of the ‘Villa del Casale’, a Roman villa discovered near Piazza Armerina (Sicily, Italy) in 1929, famous for its Roman floor mosaics. The project aims were to characterize the geology of the subsoil and provide information for solving the main building structural problems including the subsidence of some parts of the floor and the detachment of the tesserae (i.e., the tiles) of the mosaics. Another goal was the detailed study of the underground structures of the Corridor of the Great Hunt, a part of the villa strongly affected by subsidence and…
Application of non-invasive seismic techniques for the characterisation of a gravity concrete dam
2020
The use of non-invasive investigation methods is becoming frequent as a support for the monitoring of water reservoirs and for the management of dam safety. In this context, geophysical techniques are much less invasive than geotechnical tests and allow to obtain two-dimensional or three-dimensional representations of the mechanical parameters of an engineering structure. A case of application of constrained inversion and joint interpretations of non-invasive seismic techniques is discussed, in order to monitor the Dirillo gravity concrete dam, in Sicily. To investigate the foundation soil, a stratigraphic borehole and a vertical seismic profile, carried out in the same hole, were used to c…
Modelo de cabalgamiento profundo para el Alto Atlas (Marruecos). Implicaciones sísmicas en la zona de colisión entre Eurasia y Africa
2007
Previous crustal models of the High Atlas suppose the existence of a mid-crustal detachment where all the surface thrusts merged and below which the lower crust was continuous. However, both seismic refraction data and gravity modeling detected a jump in crustal thickness between the High Atlas and the northern plains. Here we show that this rapid and vertical jump in the depth of Moho discontinuity suggests that a thrust fault may penetrate the lower crust and offset the Moho (deep-rooted “thick skinned” model). The distribution of Neogene and Quaternary volcanisms along and at the northern part of the High Atlas lineament can be related to the beginning of a partial continental subduction…
Wavelet correlation filter for wide-angle seismic data
2002
A new filtering technique for single-fold wide-angle reflection/refraction seismic data is presented. The technique is based on the wavelet decomposition of a set of adjacent traces followed by coherence analysis. The filtering procedure consists of three steps. In the first, a wavelet decomposition of traces into different detail levels is performed. In the second, the coherence attributes for each level are evaluated by calculating cross-correlation functions of detail portions contained in a space–time moving window. Finally, the filtered traces are obtained as a weighted reconstruction of the trace details. Each weight is obtained from the coherence-attributes distribution estimated in …
Deep-rooted “thick skinned” model for the High Atlas Mountains (Morocco). Implications for the structural inheritance of the southern Tethys passive …
2006
A re-interpretation of the deep structure of the High Atlas is presented through integration of geophysical and geological data, highlighting the architectural significance of the southern Tethys palaeomargin. Previous crustal models suggest the occurrence of a flat intra-crustal detachment at a depth of � 20 km, a zone where surface thrusts merge and below which the lower High Atlas crust appears continuous. However, within this study seismic refraction data, electrical resistivity surveys and gravity modelling all appear to detect a jump in crustal thickness between the High Atlas and the northern plains. We interpret these data as penetration by thrusts within the ‘‘South-Atlasic fault’’…