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1.
The integrated use of electrical resistivity tomography (ERT) and ground penetrating radar (GPR) measurements, and in particular the joint analysis of 2D and 3D data, can represent a valid solution for target identification at complex archaeological sites. A good example, in this respect, is given by the case study of a Phoenician–Punic necropolis in the archaeological site of Nora, in southern Sardinia (Italy), where GPR and ERT measurements were collected before site excavation. In this specific case, the mix of soil and air in the buried chambers, as well as the orientation and the complex spatial distribution of these structures into the sandstone bedrock, generated a number of anomalies difficult to interpret only using 2D results. Only the integration of all GPR and ERT data in a 3D view, and the comparison with archaeological evidence after the excavation, allowed a solid interpretation of geophysical anomalies visible in the 2D sections. Overall, this case study demonstrates the efficiency of the combined use of GPR and ERT acquisitions and shows how, in general, only the joint analysis of 2D data and in a 3D view can help the interpretation of the real distribution of the buried archaeological remains at similar archaeological complex sites.  相似文献   

2.
A multi-method geophysical survey has been carried out on a Roman archaeological site, where part of an apse had previously been found and then refilled by archaeologists during an excavation test. Magnetic gradient measurements were performed over the whole study area and a sub-area of interesting anomalies beside the excavation test site was found. Two-dimensional filtering of a more detailed magnetic gradient map and 2D inversion of magnetic profiles were performed, using an on-purpose implemented software, in order to reduce the effect of noise and to stress the eventual presence of buried structures in agreement with the archaeologists' hypothesis. Resistivity tomography and GPR profiles were carried out along some selected profiles to obtain information on the vertical distribution of the anomalous bodies. GPR profiles, carried out in the area containing the test excavation, supplied good results, particularly when processed as time slices. The whole structure of the apse was clearly outlined. The authors were then able to suggest to the archaeologists further excavation tests on the basis of GPR results and of the filtered magnetic gradient map. A comparison of the results of the applied surveying methodologies has supplied an example of the relative strengths and weaknesses of the different electric, magnetic and GPR techniques.  相似文献   

3.
Within the extraordinary archaeological site of Pompeii, the Porta Nocera necropolis represents one of the most important sites with funerary monuments, burials and associated graves. The inherent informative potential of the archaeological/monumental heritage present in the Porta Nocera necropolis poses notable problems for the conservation and restoration of the structures and surfaces of the funerary monuments. Brought to light at different times during the second half of last century, they show signs of degradation caused by atmospheric agents and the rising level of the water table, which threatens the foundations. Other important monuments could be still buried. In order to verify both the state of preservation of the foundations of funerary buildings, the presence of still active causes of deterioration and the probable presence of other buried archaeological structures, integrated geophysical surveys, with ground penetrating radar (GPR), passive (Self Potential—SP) and active electrical resistivity tomography (ERT), were undertaken. Furthermore a three-dimensional model of the entire necropolis was created. This involved the creation of a specific survey methodology, combining laser scanning with ortho-photogrammetry using shots taken on the ground and from the air by the use of a drone. The integration of the acquired data allows us to plan future interventions of restoration.  相似文献   

4.
Muro Leccese (Lecce) contains one the most important Messapian archaeological sites in southern Italy.The archaeological interest of the site arises from the discovery of the remains of Messapian walls, tombs, roads, etc. (4th–2nd centuries BC) in the neighbourhood. The archaeological remains were found at about 0.3 m depth.At present the site belongs to the municipality, which intends to build a new sewer network through it. The risk of destroying potentially interesting ancient archaeological structures during the works prompted an archaeological survey of the area. The relatively large dimensions of the area (almost 10,000 m2), together with time and cost constraints, made it necessary to use geophysical investigations as a faster means to ascertain the presence of archaeological items. Since the most important targets were expected to be located at a soil depth of about 0.3 m, a ground-penetrating radar (GPR) survey was carried out in an area located near the archaeological excavations. Unfortunately the geological complexity did not allow an easy interpretation of the GPR data.Therefore a 3D electrical resistivity tomography (ERT) scan was conducted in order to resolve these interpretation problems.A three-way comparison of the results of the dense ERT measurements parallel to the x axis, the results of the measurements parallel to the y axis and the combined results was performed.Subsequently the synthetic model approach was used to provide a better characterization of the resistivity anomalies visible on the ERT field data.The 3D inversion results clearly illustrate the capability to resolve in view of quality 3D structures of archaeological interest. According to the presented data the inversion models along one direction (x or y) seems to be adequate in reconstructing the subsurface structures.Naturally field data produce good quality reconstructions of the archaeological features only if the x-line and y-line measurements are considered together. Despite the increased computational time required by the 3D acquisition and 3D inversion schemes, good quality results can be produced.  相似文献   

5.
The Roman fort from Sfârleanca is one of the most representative archaeological sites dating from the Roman period (2nd century A.D.) in Northern Muntenia. The existing natural and anthropic features of the environment required the application of geophysical methods in order to outline the spatial pattern of the buried remains, to define the geometry of the anthropogenic settlements and to obtain detailed information about different archaeological materials without digging. During the survey, two different geophysical methods have been employed: total magnetic field measurements and electrical resistance mapping using Twin-probe array. The instrument consists of GSM19W Overhauser magnetometers with GPS, in base-rover system, and a twin-probe array LGM 4-Point light hp. The measurements were used to draw primary maps of the physical parameters (total magnetic field strength/intensity, electrical resistance), and also processed maps (filtering, derivative). The magnetic results obtained by interpreting the anomalies yielded information about the limits of the fort, about the internal organization of the military structure (its axial road, partially its secondary road, the localization and the shape of its constructions) and at the bath and heating installation. A previously unknown element is the possible water supply pipe made of ceramic material highlighted by the mathematical modelling of the data obtained by the magnetic investigations. Electrical resistance results provide complementary information to the magnetic survey concerning the limits of the baths and the remains of the fort structure. This paper brings to light geophysical investigations into this Roman fort and baths, extending the picture produced by previous archaeological excavations that only dealt with a small part of the site. It indicates the importance of using geophysical methods in preliminary archaeological research and the advantages of combining total magnetic field measurements and electrical resistance mapping when investigating an archaeological site characterized by a number of environmental difficulties.  相似文献   

6.
The Peinan archaeological site is the most intact Neolithic village with slate coffin burial complexes in Taiwan. However, the area that potentially contains significant ancient remains is covered by dense vegetation. No reliable data show the distribution of the ancient village, and no geophysical investigation has been performed at this site. To evaluate various geophysical methods under the geological setting and surface condition of the site, the physical properties of the remains were measured and four geophysical methods involving magnetic, electromagnetic (EM), electrical resistivity tomography (ERT), and ground-penetrating radar (GPR) were tested along three parallel profiles. The results imply that the EM and magnetic methods are much cost-effective and suitable for investigating the entire area. GPR and ERT methods can provide high resolution subsurface image, which are much suitable for subsequently detail investigation.The EM and magnetic surveys were thus conducted over the entire Peinan Cultural Park to understand the distribution of the ancient building remains at the Peinan site. The results of this study were verified by subsequent excavations, which indicate that the EM survey was successful in delineating the majority of the ancient village because the basements of building are highly resistive in comparison to the background sediment. The results of this investigation suggest that the ancient village was broadly distributed over the eastern part of the Peinan Culture Park and extended to the southeast.  相似文献   

7.
The results of geophysical studies conducted with selected electrical and electromagnetic methods in the Kondratowa Valley in the Tatra Mountains (the Carpathian Mountains, Poland) are presented in the article. The surveys were performed with the following methods: electrical resistivity tomography (ERT), georadar (GPR) and conductivity meter (CM). The objective of the noninvasive geophysical measurements was to determine the thickness of the Quaternary postglacial sediments that fill the bottom of the valley and to designate the accumulation of boulders deposited on Quaternary sediments. The results of ERT surveys conducted along the axis of the valley allowed to determine the changeability of the thickness of the postglacial sediments and allowed to designate a few areas of occurrence of boulders. The ERT, GPR and CM surveys conducted across the valley allowed to designate with high accuracy the thickness of the accumulation of boulders sliding down the valley bottom from the couloirs surrounding the valley.  相似文献   

8.
This paper highlights the efficiency and complementarity of a light package of geophysical techniques to study the structure of karst Unsaturated Zone (UZ) in typical Mediterranean environment where soil cover is thin or absent. Both selected techniques, 2D Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT), are widely used in environmental studies and their application is accessible for a lot of scientists/engineers. However, GPR or ERT alone is not able to provide an enhanced characterization of geological features in karst media. In the present study, GPR results supply a near surface high resolution imaging and thus can provide relevant geological information such as stratifications and fractures. Despite the quality of the results GPR's investigation depth remains limited to around 12 m. Apparent and inverted resistivity provided by ERT surveys shows strong lateral and vertical variations. These variations can inform about general geological structuring and feature orientation. ERT is able to prospect down to 40 m but it's a low resolution integrative technique. In the study area the investigated limestone is a commonly electrical resistive formation (more than 2000 Ω.m). However deeper than 5–7 m, the ERT profiles reveal several zones of moderate resistivity (around 900 Ω.m). In these zones a stratification change corresponding to slanted bedding is clearly identified by GPR results. The combination of both GPR and ERT results can allow a well-established geological interpretation. These moderate resistivity zones with slanted beddings can explain the presence of a perennial water flow point 35 m below the surface of the studied site within the underground gallery of the Low-Noise Underground Laboratory (LSBB).  相似文献   

9.
This paper explores the suitability and advantages of combining the trenching technique with geophysical surveys [ground penetrating radar (GPR) and electrical resistivity tomography (ERT)] for sinkhole characterization in a mantled karst area. The approach is applied to two active sinkholes concealed by anthropogenic deposits and formed by contrasting subsidence mechanisms; collapse and sagging. The ERT section acquired across the collapse sinkhole images the clayey fill of the depression as an obvious low resistivity area, showing the approximate location of the sinkhole edges. Spatially dense GPR surveys provide information on the position of the boundaries of the concealed subsidence structures and their three‐dimensional (3D) internal geometry, revealing the dominant subsidence mechanism. We illustrate the impact of several factors on the quality of the GPR data such as sinkhole size, nominal frequency of the antennas, antenna shielding, and the presence of backfilled excavations and above‐surface objects. Trenches provided detailed information on the subsurface structure of the sinkhole, subsidence magnitude, partitioning of the strain, and the position of the sinkhole edges, especially when they are deep enough and excavated across the central sector and perpendicular to the boundaries. The stratigraphic and structural relationships observed in the trench were then used to infer the spatial evolution of the sinkholes (e.g. enlargement), their kinematic behavior (episodic versus progressive), and to differentiate discrete subsidence events and their associated magnitude. Numerical dates were used to estimate average subsidence rates and the recurrence of subsidence events. Such integrated data sets may be used as an objective basis to forecast the future behavior of potentially damaging sinkholes and to assess the associated hazard and risk. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

10.
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11.
The Carlo's V Castle, located in Crotone Town, on the Ionian coast of the Calabria Region (Italy), date back to the 13th century d.C. (Fig. 1). During its long life, the building changed several owners and sustained the damages and the consequent reconstructions due to the innumerable naval battles. Moreover, the castle suffered the action of the earthquakes which always afflict the region.With the principal aim of detecting the location, depth and geometry of the rests of destroyed structures, a systematic Ground Penetrating Radar (GPR) survey was carried out in the area inside the boundary walls. The results are sixty-two one-meter-spaced, filtered and migrated radargrams arranged in four 3D data-sets. From each data-set, the most significant time-slice was extracted.To reduce the ambiguity in the GPR data interpretation, additional geophysical techniques, such as Magnetic (M), and Electrical Resistivity Tomography (ERT), were carried out with a partial superimposition with the GPR data. A comparison and a joint interpretation amongst different geophysical data pointed out some very remarkable features associated to buried remains and possible buried cannonballs.With the secondary aim to check the presence of an old military walkway linking two bastions a GPR profile was carried out on the sea side boundary wall. The GPR results are in agreement with an ERT survey carried out on the same profile and consistent with the presence of an underground passage.  相似文献   

12.
Archaeological indications near Mugardos (Ferrol, NW Spain) suggest the existence of a Roman settlement. In fact, in the area were found pavements, walls with north-south and east-west orientations and some structures that endured heating. These remains are covered by soil, more than 1 m thick, and lie over schists. In order to determine the archaeological potential of the area and to delimit future excavations a geophysical survey, consisting of a joint resistivity and magnetic survey, was planned and carried out. The square array of electrodes was used and the data are discussed as apparent square array resistivity maps and azimuthal inhomogeneity ratio (AIR) maps. The magnetic survey included total field measurements using sensor heights of 0.30 and 2.30 m above the ground, so that a magnetic gradient could be computed.A combined interpretation of both resistivity and magnetic data is discussed. Later excavations have confirmed the geophysical interpretation.  相似文献   

13.
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 discontinuity ascribable to the fault zone. The information derived from different geophysical techniques, such as electrical resistivity tomography, seismic refraction tomography, ground-penetrating radar, and magnetic surveys allowed us to infer that the fractures observed at the surface could have been produced by coseismic rupture. They are conceivably linked to a strong earthquake that probably occurred in the Roman period, around mid-end of the third-century AD; time constraints are inferred through the dating of buildings of the archaeological site.  相似文献   

14.
This paper describes the ground-penetrating radar (GPR) survey performed inside the Cathedral of Valencia, Spain. It is part of historical studies performed in the Cathedral in order to add information to old maps and documents in the Cathedral Archives and also to analyze the extent and importance of potentially destructive moisture areas that were appearing on the floor. The construction of the Cathedral of Valencia occurred in three stages, all of which are well-documented in the Cathedral Archives with detailed drawings, maps, and charts. The radar data were successful in locating crypts, ossuaries, sepulchers, and graves, and the location of ancient walls that existed before the final Cathedral expansion. Three cultural layers corresponding to the three periods of construction were also identified corresponding to the Roman, Arabian and Middle Age Epochs. Measurements of relative sub-floor moisture were obtained by comparing dielectric permittivity changes and radar velocity differences between materials in humid and non-humid areas.  相似文献   

15.
Kamarina, located in southern Sicily (Italy), was an important Greek colony since its foundation in the sixth century BC. Archaeological excavations, carried out since the twentieth century, uncovered only limited portions of the site so far. Despite the importance of the Greek colony, the presence of remarkable buildings that archaeologists expected to bring to light has not found fully correspondence in the archaeological excavations. Consequently, the integrated geophysical prospection carried out in the study area is aimed to support and address the future archaeological investigations. After the photographic and thermographic survey obtained by an unmanned aerial vehicle, we performed a systematic survey through ground magnetic and GPR methods over an area of 6200 m2. The acquisition procedures have been optimized in order to get the best results combining high resolution and elevated speed of acquisition. The results derived from the three geophysical techniques have been conveniently combined by means of a cluster analysis, allowing us to clearly identify a series of buried archaeological features. Because of their geometrical characteristics, often in good agreement with the spatial arrangement of the archaeological remains at the surface, these buried archaeological features can be interpreted as roads, walls, or buildings foundations in which the various construction phases of the city can be clearly recognized. The integrated approach has proven to be essential for a robust interpretation of the archaeogeophysical investigation.  相似文献   

16.
We propose a Bayesian fusion approach to integrate multiple geophysical datasets with different coverage and sensitivity. The fusion strategy is based on the capability of various geophysical methods to provide enough resolution to identify either subsurface material parameters or subsurface structure, or both. We focus on electrical resistivity as the target material parameter and electrical resistivity tomography (ERT), electromagnetic induction (EMI), and ground penetrating radar (GPR) as the set of geophysical methods. However, extending the approach to different sets of geophysical parameters and methods is straightforward. Different geophysical datasets are entered into a trans-dimensional Markov chain Monte Carlo (McMC) search-based joint inversion algorithm. The trans-dimensional property of the McMC algorithm allows dynamic parameterisation of the model space, which in turn helps to avoid bias of the post-inversion results towards a particular model. Given that we are attempting to develop an approach that has practical potential, we discretize the subsurface into an array of one-dimensional earth-models. Accordingly, the ERT data that are collected by using two-dimensional acquisition geometry are re-casted to a set of equivalent vertical electric soundings. Different data are inverted either individually or jointly to estimate one-dimensional subsurface models at discrete locations. We use Shannon's information measure to quantify the information obtained from the inversion of different combinations of geophysical datasets. Information from multiple methods is brought together via introducing joint likelihood function and/or constraining the prior information. A Bayesian maximum entropy approach is used for spatial fusion of spatially dispersed estimated one-dimensional models and mapping of the target parameter. We illustrate the approach with a synthetic dataset and then apply it to a field dataset. We show that the proposed fusion strategy is successful not only in enhancing the subsurface information but also as a survey design tool to identify the appropriate combination of the geophysical tools and show whether application of an individual method for further investigation of a specific site is beneficial.  相似文献   

17.
Ground penetrating radar, electromagnetic terrain conductivity, and electric tomography have proven to be effective tools if they are combined together to investigate archeological sites. We have conducted a geophysical survey at the Akhmim archaeological site, the main objective of our survey is to locate additional buried structures for further excavation. Geophysical data were acquired in the area using the GEM-300 multi-frequency terrain conductivity profiler, the SIR 2000 ground penetrating radar, and the Syscal R2 resistivity meter systems. The results of the integrated interpretation show a number of buried features and a strong linear zone about 1 m wide that coincides with the suspected trend of a buried wall. There appears to be two parallel ridges of strong reflections on either side, indicating two parallel walls extended East-West and a room is identified at the bottom left comer of the site. Moreover, the interpretation results of some selected GPR and dipoledipole resistivity profiles adjacent to the open-air museum suggest the existence of a second statue of Ramses Ⅱ to the right of the previously discovered statue which could still be buried in the sand.  相似文献   

18.
Tumuli are artificially erected small hills that cover monumental tombs or graves. In this work, the surface three-dimensional (3D) Electrical Resistivity Tomography (ERT) method, composed of dense parallel two-dimensional (2D) tomographies, was used to investigate the properties of the tumuli filling material and to resolve buried archaeological structures inside the tumuli.The effectiveness of the method was investigated by numerical modeling and through 3D inversion of synthetic apparent resistivity data. A resistivity model that simulates the inhomogeneous tumulus material and the tombs that are buried inside the tumulus was assumed. The Dipole–Dipole (DD), Pole–Dipole (PD), Pole–Pole (PP), Gradient (GRAD), Midpoint-Potential-Referred (MPR) and Schlumberger Reciprocal (SCR) arrays, which are suitable for multichannel resistivity instruments, were tested. The tumulus topography (pyramid or capsized cup) was incorporated into the inversion procedure through a distorted finite element mesh. The inversion procedure was based on a smoothness constrained Gauss–Newton algorithm in which the Active Constraint Balancing (ACB) method was also applied in order to enhance the least-squares resolving power and stability.Synthetic modeling showed that the different tumulus layers and the horizontal contact of the artificial tumulus material with the natural background soil were reconstructed by all of the tested electrode arrays. Generally, PD and the GRAD arrays comprise the optimum choices to investigate the subsurface properties of a tumulus and locate buried tombs. The MPR model was inferior to the GRAD model, while the DD, PP and SCR models had the poorest resolution. It was also shown that the inversion models are practically independent from the survey direction and the topography shape of the tumulus.The real field data collected employing the PD array along a small tumulus from the archaeological site of Vergina in northern Greece enhanced the synthetic modeling results. The inversion model outlined a number of archaeological structures that exhibit a high possibility to correlate with graves. Overall, this work signifies that the surface 3D ERT method can provide a valuable tool in the non-destructive archaeological exploration of tumuli.  相似文献   

19.
The aim of the research was to examine subsurface soil layers with the use of the Ground Penetrating Radar (GPR) method. Neolithic archaeological post in Karmanowice was examined. On the basis of earlier geophysical researches and archaeological premises, eight measurement profiles had been chosen. Ground Penetrating Radar system with antenna of 500 MHz frequency was applied. The measurements were made with 30 and 60 ns time windows. The results were shown as the GPR sections. The analysis of the obtained results allowed us to outline anomalies connected with the appearance of archaeological objects in subsurface soil layers. The border between the anthropogenically changed upper layer and undisturbed loess was established, and the sections of slope wash layers were designated. Anomalies were confirmed by digging and test drillings. Additionally, 2D resistivity imaging method was used for verification of specific anthropogenic anomalies.  相似文献   

20.
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.  相似文献   

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