965 resultados para Palm, Johannes Henricus van der, 1763-1840.
Resumo:
The focus of this paper is the conversion of radiocarbon ages to calibrated (cal) ages for the interval 24,00-0 cal BP (Before Present, 0 cal BP = AD 1950), based upon a sample set of dendrochronologically dated tree rings, uranium-thorium dated corals, and varve-counted marine sediment. The 14C age-cal age information, produced by many laboratories, is converted to 14C profiles and calibration curves, for the atmosphere as well as the oceans. We discuss offsets in measured 14C ages and the errors therein, regional 14C age diferences, tree-coral 14C age comparisons and the time dependence of marine reservoir ages, and evaluate decadal vs. single-year 14C results. Changes in oceanic deepwater circulation, especialy for the 16,00-1,00 cal BP interval, are reflected in the Delta14C values of INTCAL98.
