Successful adaptation of three-dimensional inversion methodologies for archaeological-scale, total-field magnetic data sets

Cheyney, S.; Fishwick, Stewart; Hill, Ian A.; Linford, Neil

doi:10.1093/gji/ggv177

Cited by 8 publications

(4 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the absence of remnant magnetization, our approach is alternative to three‐dimensional inversion techniques that generate magnetic susceptibility maps from total field data in archaeological geophysics (e.g. Cheyney, Fishwick, Hill, & Linford, ).…”

Section: Resultsmentioning

confidence: 99%

Magnetic field modelling and analysis of uncertainty in archaeological geophysics

Schettino

Ghezzi

Pierantoni

2018

Archaeological Prospection

View full text Add to dashboard Cite

One of the major problems in the forward modelling of magnetic anomalies is the assessment of a minimum level of acceptable accuracy in the fit between observed and theoretical anomalies. We present a new approach to the analysis and interpretation of archaeological magnetic anomalies, based on classical algorithms of forward modelling and a new technique of error assessment. This approach allows us to determine geometry, physical properties, and location of buried archaeological features, as well as the occurrence of fires or other historical events that may have affected the observed magnetic signal. Our method starts from the acquisition of total field data, usually in a regular grid arrangement, and proceeds through their reduction to archaeological magnetic anomalies. This reduction is performed subtracting from the observed total field data a polynomial representation of the regional field, on the basis of a rigorous criterion that tries to separate archaeological anomalies from geological (crustal) contributions. At the next step, a map of the maximum allowed misfit is built, which depends from the estimated uncertainty at each point of the magnetic anomaly field. This map specifies the maximum allowed deviation of theoretical anomalies from the observed values. The last step is the analysis of these anomalies through a new forward modelling tool, with the objective to reconstruct the three-dimensional arrangement of buried features and possibly obtain some information about the history.

show abstract

Section: Resultsmentioning

confidence: 99%

Magnetic field modelling and analysis of uncertainty in archaeological geophysics

Schettino

Ghezzi

Pierantoni

2018

Archaeological Prospection

View full text Add to dashboard Cite

show abstract

“…The general problem of magnetic data inversion is the principal ambiguity of magnetic source models that can explain observed magnetic anomalies. Attempts have been made to reduce this ambiguity, for example, by applying weight functions regarding the magnetic field decay with depth (Argote et al, 2009), by making certain assumptions on the magnetic susceptibility (Eder-Hinterleitner et al, 1996; Herwanger et al, 2000; Neubauer and Eder-Hinterleitner, 1997), or by constraining positive and negative ranges of allowed susceptibility contrasts (Cheyney et al, 2015). Compared with these approaches, our computational scheme is quite simple, as it is basically a variant of the well-known equivalent-layer approach (e.g., Blakely, 1995), the realization of which is straightforward and merely a question of available computer power.…”

Section: Methodological Discussionmentioning

confidence: 99%

“…This trend was caused by the advantages of the method: it allows rapid data acquisition – especially if motorized – and reveals the location and contours of subsurface findings such as buildings, pits, and ditches situated in a variety of geological setups if they show a magnetization contrast to the surrounding soil (e.g. Cheyney et al, 2015; Fassbinder, 2015; Gaffney, 2008; Linford, 2006). Usually, as a final product, the measured magnetic data are depicted in the form of maps, basically areal grayscale images of the magnetic field strength.…”

Section: Introductionmentioning

confidence: 99%

Deciphering archeological contexts from the magnetic map: Determination of daub distribution and mass of Chalcolithic house remains

et al. 2019

View full text Add to dashboard Cite

The unique size and development of prehistoric megasites of the north Pontic Cucuteni-Tripolye Chalcolithic groups (4100–3600 BCE) challenge modern archeology and paleoecology. The extremely large number of houses (approximately 3000, mostly burned) necessitates the development of multidisciplinary technologies to gain a holistic understanding of such sites. In this contribution, we introduce a novel geophysical methodology and a detailed analysis of magnetic data – including evolved modeling techniques – to provide critical information about the setup of findings, enabling a thorough understanding of the settlement dynamics, apart from invasive excavation techniques. The case study is based on data from magnetic field maps and distribution maps of the daub and pottery find categories. This information is used to infer magnetic models for each find category to numerically calculate their magnetic fields for comparison with the archeological data. The comparison quantifies the sensitivity of the magnetic measurements with respect to the distribution of the different find categories. Next, via inversion computation, the characteristic depth functions of soil magnetization are used to generate maps of magnetization from the measured magnetic field maps. To validate the inverted soil magnetization maps, the magnetic excavation models are used, providing an interpretational frame for the application to magnetic anomalies outside excavated areas. This joint magnetic and archeological methodology allows estimating the find density and testing hypotheses about the burning processes of the houses. In this paper, we show internal patterns of burned houses, comparable to archeological house models, and their calculated masses as examples of the methodology. An application of the new approach to complete megasites has the potential to enable a better understanding of the settlement structure and its evolution, improve the quality of population estimations, and thus calculate the human impact on the forest steppe environment and address questions of resilience and carrying capacity.

show abstract

“…The seldom inversion of magnetic data originates from the inherent ambiguity of potential field data and the lack of constraints. Consequently, the ambiguity and the need for constraints lead to specific inversion schemes for individual sites (e.g., [3][4][5][6][7][8][9][10]). Usually the inversion computations are applied to selected magnetic anomalies rather than to complete sites.…”

Section: Introductionmentioning

confidence: 99%

Inverse Filtering of Magnetic Prospection Data—A Gateway to the Social Structure of Cucuteni–Tripolye Settlements?

et al. 2022

View full text Add to dashboard Cite

Magnetic mapping is a common method for investigating archaeological sites. Typically, the magnetic field data are treated with basic signal improving processing followed by image interpretation to derive the location and outline of archaeological objects. However, the magnetic maps can yield more information; we present a two-step automatized interpretation scheme that enables us to infer the social structure from the magnetic map. First, we derive the magnetization distribution via inverse filtering by assuming a constant depth range for the building remains. Second, we quantify the building remains in terms of their total magnetic moment. In our field example, we consider this quantity as a proxy of household prosperity and its distribution as a social indicator. The inverse filtering approach is tested on synthetic data and cross-checked with a least-squares inversion. An extensive modeling study highlights the influence of depth and thickness of the layer for the filter construction. We deduce the rule of thumb that by choosing a rather too deep and too thick a layer, errors are smaller than for layers too low and too thin. The interpretation scheme is applied to the magnetic gradiometry map of the Chalcolithic Cucuteni–Tripolye site Maidanetske (Ukraine) that comprises the anomalies of about 2300 burned clay buildings. The buildings are arranged along concentric ellipses around an inner vacant space and a vacant ring. Buildings along this ring corridor have increased total magnetic moments. The total magnetic moment indicates the remaining building material and therefore the architecture. Lastly, architecture can reflect economic or social status. Consequently, the increased magnetic moment of buildings along the ring corridor indicates a higher economic or social status. The example of Maidanetske provides convincing evidence that the inversion of magnetic data and the quantification of buildings in terms of their magnetic moments enables the investigation of the social structure within sites.

show abstract

Successful adaptation of three-dimensional inversion methodologies for archaeological-scale, total-field magnetic data sets

Cited by 8 publications

References 28 publications

Magnetic field modelling and analysis of uncertainty in archaeological geophysics

Magnetic field modelling and analysis of uncertainty in archaeological geophysics

Deciphering archeological contexts from the magnetic map: Determination of daub distribution and mass of Chalcolithic house remains

Inverse Filtering of Magnetic Prospection Data—A Gateway to the Social Structure of Cucuteni–Tripolye Settlements?

Contact Info

Product

Resources

About