Monday, June 16, 2008

Japanese use computer tomography to analyze fragile ancient artifacts

"Archaeologists working at an ancient tomb in Kurashiki, Okayama Prefecture, are taking advantage of a newly developed, computer-based technique that allows unearthed artifacts to be examined without risking damage by physically handling them.

The technique involves first encasing artifacts in medical resin to protect them from harm. Computer-based technology then applies the principles of tomography--the study of the internal structure of solid objects--to generate three-dimensional images that reveal the encased items in great detail.

Okayama University and the Kyushu National Museum, which jointly developed the method, have used it to examine artifacts found at the late fifth-century Shobuzako tomb in Kurashiki.

Excavation work at the tomb last year uncovered an intact stone chamber that contained about 200 original burial items, including mirrors and harnesses.

Researchers at Okayama University applied large amounts of a synthetic resin, originally designed for medical use, to the artifacts. After the resin had solidified, the researchers were able to remove the items in 14 solid blocks, and analyze the treasures contained in each using the tomography software.

The three-dimensional images generated through the analysis revealed minute details of the items--for example, it showed that a mirror was wrapped in several layers of cloth, and its surface was colored with the red mineral cinnabar. Researchers were also able to tell precisely how the iron parts of a harness were combined.

Takehiko Matsugi, an associate professor at Okayama University and archaeologist, said: "Excavation work is extremely demanding in terms of time, expense and researchers' physical strength. This new method enables us to examine artifacts quickly and efficiently, and to make highly accurate analyses and reproductions."