A New Dating Method Using Magnetic Declination Extracted from Historical Sources
NALANDA–SRIWIJAYA CENTRE LECTURE SERIES
About the Lecture
The magnetic north pole is a moving point at the Northern Hemisphere and is crucial to maritime navigation. The information on the magnetic north has been found encoded in ancient travel notes, rutters (mariners’ notes), and nautical charts. As the position of magnetic north moves slowly from east to west and vice versa every few hundred years, it has provided scholars with useful data to date materials which contain compass bearings.
In this talk, the dates of the compass bearings which have been recorded in certain rutters and nautical charts are identified. The Southeast Asian location which ancient Chinese navigators visited most often is singled out and used as an example to show how this method works. The historical magnetic north information for this location is first compiled in chronological sequence.
To date a compass bearing recorded in historical material, the figure from these materials is compared with the compiled historical magnetic north information. The date of the nearest magnetic north figure on the list shows when the compass bearing was taken. This dating method can be used for maps, rutters, text records, and archaeological sites or structures which were oriented to particular compass bearings. This dating method becomes useful when other dating methods, such as carbon-14, are not applicable.
About the Speaker
Dr Tai Yew Seng is Visiting Fellow at NSC. He is an archaeologist and specialises in excavating and handling ceramic from kiln sites, shipwrecks, ruins and tombs, as well as Southeast Asian maritime trade with China. His current project is on Chinese navigation charts and texts. He was a Research Fellow at the Earth Observatory of Singapore, Nanyang Technological University (NTU), and was involved in the Aceh Geohazard Project which collected and analysed over 52,000 pieces of ancient ceramics sherds. He has taught courses on Chinese culture and lectured on material culture at the Chinese Department at NTU and the National University of Singapore. He has authored a number of papers and book chapters on ceramic archaeology and maritime trade in English and Chinese.