Electrical Resistivity Tomography Investigations of MultiLayered Archaeological Settlements: Part I – Modelling

Self Cite

To determine the data acquisition and inversion capabilities of electrical resistivity tomography (ERT), which is used in multilayered archaeological settlements, an ERT survey was carried out at the Old Smyrna Höyük site, in the city of İzmir, Turkey. This site dates from the third millennium BC and ERT applications were performed using five different arrays (Wenner-alpha, Wenner-Schlumberger, dipole-dipole, pole-pole and pole-dipole). The resistivity distribution of the subsurface was investigated by two-dimensional and three-dimensional inversion routines, which use data obtained along orthogonal lines. To test the inversion treatments, 'semi-fully three-dimensional' and 'quasi-threedimensional' approaches were also investigated, and comparison indicated a clear distinction between them. The results show that the quasi-three-dimensional solution had insufficient resolution, whereas the semi-fully threedimensional data sets provide interpretable images of the subsurface. In addition, the effects of electrode array type and line interval and orientation were tested to define suitable ERT survey strategies for multilayered archaeological settlements. The array investigations show that dipole-dipole, pole-pole and pole-dipole arrays presented better quality images than the others. The line orientation tests performed in two perpendicular directions (N-S and E-W oriented lines) show that the N-S oriented lines are more suitable in terms of defining the buried architectural plan of Old Smyrna Höyük according to depth-slicing visualizations. However, the combination of the two perpendicular data sets could be useful if large between-line intervals are used. Finally, this ERT study clearly revealed the layered stratigraphy of Old Smyrna Höyük.

Section: Discussionsupporting

confidence: 84%

Electrical Resistivity Tomography Investigations of Multilayered Archaeological Settlements: Part II – A Case from Old Smyrna Höyük, Turkey

Berge

Drahor

2011

Self Cite

“…Three‐dimensional ERT modelling studies point out that the dipole–dipole array generates images that are close to the models used (Berge & Drahor, ). Additionally, this array was chosen to perform the survey as it is very sensitive to lateral changes in resistivity (very good horizontal resolution), has a good lateral coverage, and low electromagnetic coupling between the current and potential circuits.…”

Section: Methods and Instrumentationmentioning

confidence: 74%

Three‐dimensional modelling of a pre‐Aksumite settlement at the archaeological site of Seglamen, Aksum, northern Ethiopia using integrated geophysical techniques

Assefa

Haile

Sernicola

2018

This geophysical study is part of a multidisciplinary archaeological research project designed to provide the framework for the reconstruction of the cultural and environmental history of the region to the southwest of Aksum and for the production of a detailed archaeological map for the cultural heritage management of central Tigray. Seglamen, near Aksum in north Ethiopia, an area of about 70 000 m2, is dated from the early to mid‐first millennium bce and has been detected and excavated since 2010 by the Italian Archaeological Expedition of the University of Naples “L'Orientale”. An objective of this study was to develop a geophysical model that defines the archaeological context of a multilayered archaeological site. In doing so, it was also aimed at guiding future excavations operated by archaeologists on the site, thereby assess the geophysical techniques that work well in this area and make recommendations to several archaeological research projects that have been operating at and around Aksum, with similar archaeological context. Magnetic and electrical resistivity tomography (ERT) techniques were employed. The magnetic reconnaissance survey carried out at 2 m station spacing and 5 m line spacing covering the area and has outlined for further detailed investigation localized anomalies for the ERT. Detailed ERT survey was conducted on a rectangular grid of 21.75 × 44.25 m2 with 0.75 m unit electrode spacing and 0.75 m line spacing. It has yielded two‐dimensional (2D) and three‐dimensional (3D) electrical resistivity sections of the surveyed area. From combined interpretation of the magnetic and electrical imaging survey data, it was possible to delineate localized anomalous zones that could be associated with the existence of subsurface features of archeological interest. Interpreted stone‐based walls were validated through test excavations that revealed well preserved and collapsed walls. These cultural structures are sometimes located at depths of about 20 cm so there is a high possibility of destruction by farming activities of local farmers; ultimately, we would urge conservation work in this area.

“…Underground voids develop naturally as karst or caves with irregular topographies while cavities such as tombs or catacombs, underground mines, tunnels, etc., produced by human activities generally have well defined geometry. Since the electrical resistance of the void is higher than the surrounding substrate, two-dimensional (2D) and three-dimensional (3D) electrical resistivity tomography (ERT) is used successfully for the non-destructive characterization of mounds and tumuli (Papadopoulos, Yi, Kim, Tsourlos, & Tsokas, 2010;Wake, Mojica, Davis, Campbell, & Mendizabal, 2012), for the investigation of multilayered human settlements (Berge & Drahor, 2011a, 2011bTestone, Longo, Algeri, Bottacchi, & Campo, 2012), for the mapping of buried walls, voids and passage-ways (Leucci, Greco, De Giorgi, & Mauceri, 2007;Testone, Longo, Bottacchi, & Mameli, 2015), for the detection of buried and hypogean tombs and defining their geometry (Arato, Piro, & Sambuelli, 2015;Elwaseif & Slater, 2010;Piro, Tsourlos, & Tsokas, 2001).…”

Section: Introductionmentioning

confidence: 99%

Geophysical prospection pilot in rock‐cut tombs: The case study of Anghelu Ruju necropolis (Sardinia)

Testone

Longo

Mameli

et al. 2018

Electrical resistivity tomography (ERT) and ground penetrating radar (GPR) surveys were conducted in the Anghelu Ruju hypogeic necropolis in northern Sardinia (Italy). The main purpose was to calibrate both techniques on a known and already dug tomb. After the calibration the survey was extended to a neighbouring unexplored area with the aim to demonstrate new hypogeic structures. A comparison of the high‐resolution GPR and ERT models was made, and their results are discussed in terms of providing a more complete picture that would not be attainable using a single method. Several anomalies were identified that might represent previously unknown rock‐cut tombs and burial sites in the central part of the investigated area.