At the bottom of a lake near Japan's Wakasa Bay, more than 50,000 years of history has been pulled out of the ground in the form of sediment and leaves.
The information contained in those samples will allow scientists to determine the age of organic materials and fossils with new clarity by improving carbon dating, according to a study published Thursday in the journal Science.
Carbon dating works by detecting the relative amounts of two varieties of carbon: carbon-14, or C-14, and carbon-12, or C-12. Animals take up both varieties during our lifetimes, but only C-14, which is also known as radiocarbon, decays over time. That means that the amount of C-14 relative to C-12 can be used to determine how much time has passed since the fossil was alive.
But the amount of C-14 in the atmosphere changes over time, which has the potential to throw off the calculations. So scientists need ways to correlate their measurements to fossils whose timelines are known. The best examples of this are tree rings, as scientists can relate the C-14 levels to the rings that build up over time. But the oldest tree ring examples are only about 13,000 years old.
