Dendrochronology is the science of dating the age of timber by comparing the sequence of its tree-ring width variations with that of timbers of a known date, ideally belonging to the same species and from the same location. As with any science it is not without its difficulties(c), but is generally considered to be more accurate than radiocarbon dating, which is frequently calibrated using dendrochronology. Fully anchored chronologies now exist for river oaks in parts of Germany dating back over 10,000 years and a similar chronology extending back 6500 years exists for the bristlecone pine of California’s White Mountains. A new project(b) involving the Kauri trees of New Zealand has commenced, which should give an accurate climate record for the past 30,000 years. Some of these trees are dated to 130,000 years ago.
Professor Mike Baillie, one of the leading dendrochronologists in Europe, has written about ‘dendro’ evidence of cometary impacts. One such impact has been suggested by a number of commentators, as the possible cause of the demise of Atlantis.
While the science of dendrochronology is perfectly sound there can a need for fine tuning to take account of unexpected factors like the nibbling of tree trunks by animals such as sheep. Recent studies in Norway(d) over a nine year period provided data enabling appropriate calibration to be achieved.
In 2014, Gunnar Heinsohn, a German chronology revisionist, questioned the value of dendrochronology, which was followed by a rebuttal from Mike Baillie(e). This debate continues, with many specific details far from resolved (f).
Professor Henri D. Grissino-Mayer, of the University of Tennessee, has a most informative website(a) on dendrochronology.
(c) http://uts.cc.utexas.edu/~wd/courses/373F/notes/lec20den.html (offline May 2016)
^see Archive 3046