Palaeoenvironmental research
Dr Jonathan Palmer extracts a biscuit for carbon dating and tree-ring analysis from a 12,000-yr old kauri log excavated from farmland at Towai, Northland.
The Northland sub-fossil kauri resource represents one of the world’s foremost archives of atmospheric records during the last 60,000 years.
Kauri logs are buried in bogs scattered over a 300 km stretch of northern New Zealand. This wood contains an immense, high-resolution store of information about past environmental conditions, including climate and landforms. Alan Hogg is leading a team comprising 3 radiocarbon laboratories (Wk, UCI, OxA) to study atmospheric 14C concentrations during the Younger Dryas (YD) Stadial, an abrupt Northern Hemisphere (NH) cooling episode, to decipher the timing, duration and causes of this critical cooling event. The 3 laboratories have completed ~700 14C measurements from the time interval ~12,860 – 11,700 cal BP, producing the most accurate and precise 14C data set for any time period.
A paper describing the YD kauri project and revealing errors in the NH IntCal09 data set has been published in Radiocarbon – free to download here (Hogg et al 2013b).