Non-invasive methods for in situ assessing and monitoring the vulnerability of rock art monuments

In England, as in many other countries, there are significant numbers of surviving open-air rock art monuments, which are exposed to all the extremes of weather conditions. Despite this, they have managed to survive over 4,000 years. The decay rate of these rocks must have been very slow, however, with the increased pollution levels in the last couple of hundred years the rate of decay may have accelerated. It is therefore important to monitor the microscopic changes in these rocks over time in order to inform and help with the formulation of conservation strategy.

English Heritage manages many important open-air rock art monuments in upland areas which need to be preserved in context for public understanding and enjoyment. There is at the moment considerable uncertainty about how to assess condition and vulnerability in these monuments. Porosity is an important indicator of vulnerability, as voids are open to freeze-thaw, to rootlets and to hyphae. A non-invasive method of measuring porosity below a carved rock surface would make an important contribution to assessing vulnerability and understanding decay.

With the portable optical coherence tomography (OCT) and magnetic resonance imaging (MRI) instruments available at NTU, we will be able to non-invasively image the surface and subsurface of a rock art panel and measure the vulnerability of the rock art monuments.

Academic Investigator: Professor Haida Liang

Co-supervisors

• Dr Martin Bencsik
• Sebastian Payne, English Heritage

PhD research student

• Elizabeth Bemand

Conference Presentations

• Presentation by Elizabeth Bemand on "Non-invasive in situ moisture detection with near infrared hyperspectral imaging and NMR" at the international workshop "Application of imaging science to the interdisciplinary study of wall paintings along the silk road", 1-3 December 2010, Xi'an China
• Presentation by Elizabeth Bemand on "Optical Coherence Tomography for non-invasive in-situ monitoring of the bioreceptivity of sandstone monuments" at the International Conference on the Research and Conservation of the Kucha Caves, August 2011 Kizil, China
• Presentation by Elizabeth Bemand on "OCT and NMR for non-invasive in-situ monitoring of the vulnerability of rock art monuments" at SPIE Optical Metrology symposium, O3A: Optics for Arts, Architecture, and Archaeology, 23-26 May 2011 in Munich, Germany
• Presentation by Elizabeth Bemand at Photonex Optical Metrology October 2011, Coventry
• Presentation by Elizabeth Bemand on "Non-invasive methods for in-situ monitoring of the vulnerability of rock art monuments", The European Association of Archaeologists 16th Annual Meeting 1-5 September 2010, The Hague, Netherlands
• Presentation and poster by Elizabeth Bemand at the Science and Heritage Programme Collaborative Research Studentship Symposium. Lady Margaret Hall, Oxford, 14 September 2010

Journal Publications

• Bemand E., Liang H., 2013, Optical Coherence Tomography for vulnerability assessment of sandstone, Applied Optics, 52 (14) 3387-3393
• Bemand, E., M. Bencsik, H. Liang, 2011, OCT and NMR for non-invasive in-situ monitoring of the vulnerability of rock art monuments, SPIE 8084, 80840H
• Bemand, E., H. Liang, M. Bencsik, 2014, Chapter on "Non-invasive methods for in-situ assessing and monitoring of the vulnerability of rock-art monuments" in Open-air Rock-art Conservation and Management: State-of-the-art and Future Perspectives, Edited by Timothy Darvill and Antonio Pedro Batarda Fernandes