What factor reduces the accuracy of radiocarbon dating easy webbsite updating
The patterns in America could not bias the work on patterns in Europe, because the specimens came from two different local climates, separated by an ocean.
The scientists worked independently of one another.
However, they did agree with the bristlecone chronology as far back as it could be checked by the shorter chronologies.
That is, rings of the same putative dendrochronological age were found to contain the same amount of radiocarbon, and to give the same pattern of fluctuations over time.
This objective, quantitative test of dendrochronology showed it to be reliable and accurate.
But for the specimen to be useful in extending the tree-ring chronology, the absolute calendar age of its rings must be determined.
The annual growth rings vary in thickness each year depending on environmental factors such as rainfall.
By matching ring-width patterns in a specimen of known age (starting with living specimens) to ring-width patterns in an older specimen, the proper placement of the older specimen is determined.
Tree-ring chronologies have been extended to 10,000 years before present in this way.