708 research outputs found
Calibration of the Radiocarbon Time Scale for the Southern Hemisphere: AD 1850-950
No full textWe have conducted a series of radiocarbon measurements on decadal samples of dendrochronologically dated wood from both hemispheres, spanning 1000 years (McCormac et al. 1998; Hogg et al. this issue). Using the data presented in Hogg et al., we show that during the period AD 950-1850 the 14C offset between the hemispheres is not constant, but varies periodically (~130 yr periodicity) with amplitudes varying between 1 and 10‰ (i.e. 8-80 yr), with a consequent effect on the 14C calibration of material from the Southern Hemisphere. A large increase in the offset occurs between AD 1245 and 1355. In this paper, we present a Southern Hemisphere high-precision calibration data set (SHCal02) that comprises measurements from New Zealand, Chile, and South Africa. This data, and a new value of 41 ± 14 yr for correction of the IntCal98 data for the period outside the range given here, is proposed for use in calibrating Southern Hemisphere 14C dates
The design of phishing studies: challenges for researchers
No full textAbstract not availableKathryn Parsons, Agata McCormac, Malcolm Pattinson, Marcus Butavicius, Cate Jerra
w,w'-Dialkylated Tetraaza Linear Ligands as More Appropriate Reference Ligands for Tetraaza Macrocycles. A Comparison of 1,4,7,10-Tetraazacyclododecane with 3,6-Diaza-1,8-diamonooctane
No full text
Individual differences and Information Security Awareness
No full textAbstract not availableAgata McCormac, Tara Zwaans, Kathryn Parsons, Dragana Calic, Marcus Butavicius, Malcolm Pattinso
Variations of radiocarbon in tree rings: southern hemisphere offset preliminary results
No full textThe Queen's University of Belfast, Northern Ireland and University of Waikato, Hamilton, New Zealand radiocarbon laboratories have undertaken a series of high-precision measurements on decadal samples of dendrochronologically dated oak (Quercus patrea) and cedar (Libocedrus bidwillii) from Great Britain and New Zealand, respectively. The results show a real atmospheric offset of 3.4 ± 0.6% (27.2 ± 4.7 ¹⁴C yr) between the two locations for the interval AD 1725 to AD 1885, with the Southern Hemisphere being depleted in ¹⁴C. This result is less than the value currently used to correct Southern Hemisphere calibrations, possibly indicating a gradient in Δ¹⁴C within the Southern Hemisphere
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