Supervisors: Dr. Ian Hill (University of Leicester), Dr. Neil Linford (English Heritage), Dr. Stewart Fishwick (University of Leicester), Mr. Chris Leech (Geomatrix Earth Science)

Research

Archaeomagnetic surveying is commonly used as a first-pass archaeological survey, to target areas for more detailed investigation, or excavation. Results are typically viewed as greyscale maps and anomalies interpreted as likely archaeological structures. This technique ignores some of the information content of the data.

The data collected using dense spatial sampling with modern precise instrumentation are capable of yielding numerical estimates of the depths to buried structures, and their physical properties. The magnetic field measured at the surface is a superposition of the responses to all anomalous magnetic susceptibilities in the subsurface, and is therefore capable of revealing a 3D model of the earth's magnetic properties.

Starting model rapidly generated from the data, prior to inversion.

3D inversion techniques can yield a model of subsurface susceptibilities with a good fit to the recorded data, however, the final model is biased to the starting model provided, and the run time and computer power are often restrictive.

My PhD aims to use methods involving combinations of the horizontal and vertical derivatives, analytic signal, pseudo-gravity transformation and Euler deconvolution to derive initial values for position and susceptibility of anomalous features from the data.

Using these rapidly obtained results, inversion of data can be achieved quicker and with increased confidence in the final result. Many of these methods are proven on regional-scale surveys, but have not been applied to the specific problems of high resolution archaeological data.

Depth slices from 3D magnetic susceptibility model of a buried Roman temple, Silchester, Hampshire, UK

Recent publications

Cheyney S, Hill I, Linford N. 2011. Advantages to Using the Pseudogravity Transformation to Aid Edge Detection of Total Field Archaeomagnetic Datasets. Archaeological Prospection 18(2) p.81-93

Cheyney, S, Hill I, Linford N, Fishwick S, Leech, C. 2011. 3D quantitative interpretation of archaeo-magnetic data: Adaptation of aero-magnetic interpretation techniques for archaeological purposes. Paper presented at the AGU Fall Meeting, 5th-9th December 2011, NS14A-04.

Cheyney S, Hill I, Linford N, Fishwick S, Leech, C. 2010. Adaptation of aeromagnetic interpretation techniques for archaeomagnetic purposes. Recent Work In Archaeological Geophysics. NSGG.

Cheyney S, Hill I, Linford N, Leech C. 2010. Investigating automated depth modelling of archaeo-magnetic datasets. Geophysical Research Abstracts 12

Other research interests

• Controlled Source Electromagnetic Imaging (CSEM) - 2 years industry experience
  
• Seismic Tomography - Undergraduate dissertation and Masters project.