Search results for "Seismic refraction"
showing 9 items of 19 documents
Hydrogeological and geotechnical modeling of the foundation soils of Maredolce Lake in Palermo, aided by geophysical surveys
2019
The cultural heritage of Maredolce (Palermo) includes an Arab-Norman castle that originally stood on the shores of an artificial lake carved out of a basin dug out of the calcarenite and filled with water thanks to the channeling of the springs of San Ciro upstream. Subsequently, the lowering of the water table and the high hydraulic permeability of the outcropping rocks caused the lake to dry up. Recently, a project of enhancement of the cultural heritage required the restoration of the lake. The geophysical study presented here, including the integrated use of different techniques such as electrical and seismic tomography, Multichannel Analysis of the Surface Waves and ambient vibration r…
Multivariate modelling of geophysical tomography data to identify a tectonized area
2018
An integrated analysis approach, based on geological investigations and 2D high-resolution shallow geophysical data, was proposed along a slope in the Bellolampo landfill area (Palermo, Italy) where the presence of a fault zone was hypothesized. Geophysical surveys included electrical resistivity tomography (ERT), induced polarization tomography (IPT) and seismic refraction tomography (SRT) techniques. The inversion of single geophysical parameter often does not allow to justify the complexity of the subsoil structures. The most appropriate solution should be to add additional physical or geological information so to get a constrained geological model. However, it is not at all easy to work…
Statistical approach for cavity detection using seismic refraction and electrical resistivity data
2017
To test limitations and effectiveness of seismic tomography when coupled to geoelectrical technique for cavity detection 2D synthetic models were used. Synthetic models were created with different number of cavity and blocks of highly cohesive lithological material (high seismic velocity and resistivity values). A modified version of multiple gradient (Martorana et al., 2016) has been used for electrical sequence. The cluster analysis performed on static units defined by electrical resistivity values, P wave velocities, and seismic density on coincident sections, allowed to interpret subsoil structures. The use of the non-hierarchical clustering algorithm has been chosen because it is less …
Cluster analysis for cavity detection using seismic refraction and electrical resistivity tomography
2017
Geophysical methods (in particular ERT technique) constitute an excellent tool for the detection of buried cavities. However the integration approach of e different geophysical methods could minimize the ambiguity of geophysical interpretation of the buried cavity. The technique of electrical tomography has been joined to the technique of seismic refraction tomography in order to obtain more robust interpretations. Many tests have been carried out using synthetic data and experimental ones. It was finally used a statistical approach based on cluster analysis of the P-wave velocity, the density of the seismic rays and the electrical resistivity of the synthetic and experimental models. Distr…
Crustal structure of the Reykjanes Ridge near 62°N, on the basis of seismic refraction and gravity data
2007
Explosion deep seismic sounding data sections of high quality had been obtained with RV Meteor in the Reykjanes Iceland Seismic Project (RRISP77 [Angenheister, G., Gebrande, H., Miller, H., Goldflam, P., Weigel, W., Jacoby, W.R., Palmason, G., Bjornsson, S., Einarsson, P., Pavlenkova, N.I., Zverev, S., Litvinenko, I.V., Loncarecic, B., Solomon, S., 1980. Reykjanes Ridge Iceland Seismic Experiment (RRISP 77). J. Geophys. 47, 228–238]) which close an information gap near 62°N. Preliminary results were presented by Weigel [Weigel, W., 1980. Aufbau des Reykjanes Ruckens nach refraktionsseismischen Messungen. In: Weigel, W. (Ed.), Reykjanes Rucken, Island, Norwegischer Kontinentalrand. Abschluss…
Geophysical study of an landslide in northern Sicily
2002
The San Fratello area in the Nebrodi Mountains (northern Sicily) is a region of high instability. It has suffered many devastating occurrences, which have hit and destroyed the village of San Fratello. At present the area is still subject to a high landslide risk. A series of geophysical surveys have been carried out with the aim of determining the thickness and dimensions of the landslide body as well as some tectonic features, in order to gain insight into the evolution of the landslide. The following geophysical techniques have been used: borehole seismic tomography, i.e. down-hole tomographic seismic soundings (DH TSS), time-domain electromagnetic (TDEM) soundings and georadar profiling…
Recognition of earthquake-induced damage in the Abakainon necropolis (NE Sicily): results from geo-morphological, geophysical and numerical analyses
2017
Seismotectonic activity and slope instability are a permanent threat in the archaeological site of Abakainon and in the nearby village of Tripi in NE Sicily. In recent times, signs of an ancient earthquake have been identified in the necropolis of Abakainon which dating was ascertained to the first century AD earthquake. The site is located on a slope of Peloritani Mts. along the Tindari Fault Line and contains evidence for earthquake-induced landslide, including fallen columns and blocks, horizontal shift and counter slope tilting of the tomb basements. In this paper, we used an integrated geomorphological and geophysical analysis to constrain the landslide. The research was directed to th…
Integration of constrained electrical and seismic tomographies to study the landslide affecting the cathedral of Agrigento
2014
The Cathedral of Saint Gerland, located on the top of the hill of Agrigento, is an important historical church, which dates back to the Arab–Norman period (XI century). Unfortunately throughout its history the Cathedral and the adjacent famous Archaeological Park of the 'Valley of the Temples' have been affected by landslides. In this area the interleaving of calcarenites, silt, sand and clay is complicated by the presence of dislocated rock blocks and cavities and by a system of fractures partly filled with clay or water. Integrated geophysical surveys were carried out on the north side of the hill, on which the Cathedral of Agrigento is founded, to define lithological structures involved …
Geomorphological and geophysical investigations to study the landslide affecting the archaeological site of abakainon
2016
In recent years, a detailed archeoseismological investigation has been carried out in the necropolis of Abakainon in order to identify traces of an ancient earthquake. Although the identification of seismic damage was undoubtedly attributed to the 1st century AD earthquake, it was hypothesised that the level of damaging observed in the necropolis, as well as the counter slope tilting of the tomb basements may have also caused by a seismo-induced landslide, which produced locally an amplification of the seismic shaking. In order to identify the landslide, on which the Greek site lies, detailed geomorphological and geophysical surveys have been carried out. The research was directed to the ac…