Radiocarbon dating range
The technique hinges on carbon-14, a radioactive isotope of the element that, unlike other more stable forms of carbon, decays away at a steady rate.
Radiocarbon present in molecules of atmospheric carbon dioxide enters the biological carbon cycle: it is absorbed from the air by green plants and then passed on to animals through the food chain.
Two distinct sediment layers have formed in the lake every summer and winter over tens of thousands of years.
The researchers collected roughly 70-metre core samples from the lake and painstakingly counted the layers to come up with a direct record stretching back 52,000 years.
What methods do they use and how do these methods work?
In this article, we will examine the methods by which scientists use radioactivity to determine the age of objects, most notably carbon-14 dating.