Precise radiocarbon dating using Miyake event
Prof. Andrzej Rakowski1, Prof. Marek Krąpiec2, Dr. Jacek Pawlyta1, M.Sc. Damian Wiktorowski2
1Silesian University Of Technology, Gliwice, Poland, 2AGH, University of Sciences and Technology, Kraków, Poland
Miyake et al. (2012, 2013 and 2014) described a sudden increase of radiocarbon (14C) concentration in annual tree rings of Japanese cedar (Cryptomeria japonica) and Hinoki cypress (Chamaecyparis obtusa) between AD 774 and 775 and between AD 993 and 994.
Due to the characteristic of the sharp increase in radiocarbon concentration that occurs in Miyake event, and due to the global character of this event, it is possible to use it for accurate dating of annual tree rings, using radiocarbon method. In practice, linking the relative dendrochronological dating and radiocarbon analysis of annual growth rings is possible by useing the “Wiggle matching” technique to precisely determine the calendar age of samples of pine from the floating pine chronology (2U_02A) for central Poland. Absolute dating chronology 2U_02A is covering 227 years, determined on the basis of 50 individual sequences, and is of great importance for archaeology of the early Middle Ages. This is particularly important for the polish history, as during the period covered by this chronology, evolutionary changes occurred, such us the transition from tribal organization to state organization and the emergence of a series of fortified towns, for which dendrochronology dating without pine standard is difficult. So far, summarized standard curves for pine in Poland date back from the present to 1106 AD for Gdańsk Pomerania (Zielski 1997) and 1091 AD for Lesser Poland (Szychowska-Krąpiec 2010) and does not include the Xth century AD.
The procedure is divided into three phases. In the Phase I, four samples, each contain five consecutive annual rings, were selected from the floating chronology 2U_02A. The results of wiggle-matching are presented on Figure 3. Taking into account position of the first ring dated with the radiocarbon method, it is possible to determine the period represented by the curve 2U_02A for the years 860-180 (±10) cal. AD. In the Phase II, five samples of annual tree rings were selected and measured to compare with the curve representing radiocarbon concentrations for the period AD 986 – 1013. The results are presented in Figure 4. In the last Phase III, which is planned, around 25 annual ring samples, covering the period between AD 985 – 1010, will be measured and compared with the curve form Miyake et al. (2013, 2015).
My scientific career started in the year 1993; since then, I have been employed in the Institute
of Physics (Division of Radioisotopes) at Silesian University of Technology (SUT) in Gliwice.
Between 1995 and 1999, I undertook my doctoral study in SUT, receiving in 1999 the degree
of Doctor of Sciences in Physics.
Most of my research is concerned with applications of the radiocarbon method in the study
of the changes in the environment under the influence of human activities.