Carbon dating tree
“Variations in atmospheric radiocarbon concentration are largely the result of carbon dioxide emissions from activity from volcanoes and the ocean, but they are also influenced by changes in solar activity,” explains Oxford University archaeologist Michael Dee, lead author of the study. Such markers can be easily identified in known-age tree-rings and are fixed in time.” According to the researchers, archaeologists have been forced to rely on relatively sparse evidence to date the history of Western civilization before 763 B. In addition to being imprecise, dating archaeological finds by comparing the ratio between two isotopes of the element carbon—slowly decaying carbon-14 and stable carbon-12—in organic materials is expensive. Another potential obstacle is that it’s uncertain just how often intense bursts of solar radiation have struck the Earth.
Dee and co-author Benjamin Pope believe that by mining tree-ring data, scientists will be able to detect similar spikes to those of 775 A. Still, Dee is optimistic about the applicability of the research team’s findings.
Discovered in 2004, the lone Norway spruce—of the species traditionally used to decorate European homes during Christmas—represents the planet's longest-lived identified plant, Kullman said.
The spruce's stems or trunks have a lifespan of around 600 years, "but as soon as a stem dies, a new one emerges from the same root stock," Kullman explained.The Oxford University researchers who authored the study say that those rings could act as “secret clocks” to allow archaeologists to pinpoint exact dates of major events that occurred in ancient history, such as the building of the Great Pyramid of Giza, the collapse of Mayan civilization and the arrival of the Vikings in North America.The dramatic jumps in carbon-14 produced by strong solar storms would be present not just in tree rings but in the surviving tissue of any plant growing at the time.Purpose To determine the absolute age of wood and organic artifacts.Method A scientific date is either absolute (specific to one point in time) or relative (younger or older than something else).
The total mass of the isotope is indicated by the numerical superscript.