Problems with radiocarbon dating methods

Radiometric Dating: Problems with the Assumptions

Radiocarbon dating is a key tool archaeologists use to determine the age of plants and objects made with organic material. But new research shows that commonly accepted radiocarbon dating standards can miss the mark -- calling into question historical timelines. Archaeologist Sturt Manning and colleagues have revealed variations in the radiocarbon cycle at certain periods of time, affecting frequently cited standards used in archaeological and historical research relevant to the southern Levant region, which includes Israel, southern Jordan and Egypt. These variations, or offsets, of up to 20 years in the calibration of precise radiocarbon dating could be related to climatic conditions. Pre-modern radiocarbon chronologies rely on standardized Northern and Southern Hemisphere calibration curves to obtain calendar dates from organic material. These standard calibration curves assume that at any given time radiocarbon levels are similar and stable everywhere across each hemisphere.

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Scientists who study organic materials from the past 55, years may see some changes in their data. By Megan I. More than 3, years ago a catastrophic volcanic eruption struck ancient Thera, known today as the Greek island of Santorini. Ash and pumice rained across the Mediterranean, and tsunami waves rolled onto faraway shores in Crete. In the s archaeologists on Santorini uncovered a Minoan settlement frozen in time, with vibrant wall frescoes decorating multistory houses, all buried by volcanic debris.

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Radiocarbon dating also referred to as carbon dating or carbon dating is a method for determining the age of an object containing organic material by using the properties of radiocarbon , a radioactive isotope of carbon. The method was developed in the late s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon 14 C is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting 14 C combines with atmospheric oxygen to form radioactive carbon dioxide , which is incorporated into plants by photosynthesis ; animals then acquire 14 C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of 14 C it contains begins to decrease as the 14 C undergoes radioactive decay.

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Carbon dating accuracy called into question after major flaw discovery

Dating is everything in archaeology. Exciting discoveries of ancient burial sites or jewelry might make headlines, but for scientists, this kind of discovery is only meaningful if we can tell how old the artifacts are. So when chemist Willard Libby developed radiocarbon dating in , it was a breakthrough for archaeology and he was awarded a Nobel prize for his achievement.

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