Radiocarbon 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.
Dendrochronology is the scientific method of dating tree rings to the exact year they were formed in a tree. As well as dating them, this can give data for dendroclimatology, the study of climate and atmospheric conditions during different periods in history from the wood of old trees. Dendrochronology derives from the Ancient Greek dendron, meaning "tree", khronos, meaning "time", and -logia, "the study of".
Carbon-14, C-14, 14
C or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples. Carbon-14 was discovered on February 27, 1940, by Martin Kamen and Sam Ruben at the University of California Radiation Laboratory in Berkeley, California. Its existence had been suggested by Franz Kurie in 1934.
A varve is an annual layer of sediment or sedimentary rock.
Before Present (BP) or "years before present (YBP)" is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date (epoch) of the age scale, with 1950 being labelled as the "standard year". The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must account for.
Tephrochronology is a geochronological technique that uses discrete layers of tephra—volcanic ash from a single eruption—to create a chronological framework in which paleoenvironmental or archaeological records can be placed. Such an established event provides a "tephra horizon". The premise of the technique is that each volcanic event produces ash with a unique chemical "fingerprint" that allows the deposit to be identified across the area affected by fallout. Thus, once the volcanic event has been independently dated, the tephra horizon will act as time marker. It is a variant of the basic geological technique of stratigraphy.
The Minoan eruption was a catastrophic volcanic eruption that devastated the Aegean island of Thera circa 1600 BCE. It destroyed the Minoan settlement at Akrotiri, as well as communities and agricultural areas on nearby islands and the coast of Crete with subsequent earthquakes and paleotsunamis. With a Volcanic Explosivity Index (VEI) of 6, it resulted in the ejection of approximately 28–41 km3 (6.7–9.8 cu mi) of dense-rock equivalent (DRE), the eruption was one of the largest volcanic events in human history. Since tephra from the Minoan eruption serves as a marker horizon in nearly all archaeological sites in the Eastern Mediterranean, its precise date is of high importance and has been fiercely debated among archaeologists and volcanologists for decades, without coming to a definite conclusion.
The Oruanui eruption of New Zealand's Taupō Volcano was the world's most recent supereruption, and largest phreatomagmatic eruption characterised to date.
Lake Taupō, in the centre of New Zealand's North Island, fills the caldera of the Taupō Volcano, a large rhyolitic supervolcano. This huge volcano has produced two of the world's most powerful eruptions in geologically recent times.
The Hallstatt plateau or the first millennium BC radiocarbon disaster, as it is called by some archaeologists and chronologists, is a term used in archaeology that refers to a consistently flat area on graphs that plot radiocarbon dating against calendar dates. When applied to the Scythian epoch in Eurasia, radiocarbon dates of around 2450 BP, so c. 500 BC, always calibrate to c. 800–400 BC, no matter the measurement precision. The radiocarbon dating method is hampered by this large plateau on the calibration curve in a critical period of human technological development. Just before and after the plateau, radiocarbon calibration gives precise dates. However, during the plateau the calendar date estimates obtained when calibrating single radiocarbon measurements are very broad and cover the entire duration of the plateau. Only techniques like wiggle matching can yield more precise calendar dates during this period. The plateau is named after the Hallstatt culture period in central Europe with which it coincides.
Gabarnmung is an archaeological and rock art site in south-western Arnhem Land, in the Top End of Australia’s Northern Territory. Habitation of the site has been dated to at least 44,000 years ago, placing it among the oldest radiocarbon dated sites in Australia. The oldest rock art was produced more than 28,000 years ago, making it the oldest securely dated prehistoric art in Australia. The cave was still visited by members of the Jawoyn within living memory, possibly until as late as the 1950s, but its existence had been forgotten until its 2006 rediscovery.
The ASPRO chronology is a nine-period dating system of the ancient Near East used by the Maison de l'Orient et de la Méditerranée for archaeological sites aged between 14,000 and 5,700 BP.
The 774–775 carbon-14 spike is an observed increase of around 1.2% in the concentration of the radioactive carbon-14 isotope in tree rings dated to 774 or 775 CE, which is about 20 times higher than the normal year-to-year variation of radiocarbon in the atmosphere. It was discovered during a study of Japanese cedar tree-rings, with the year of occurrence determined through dendrochronology. A surge in beryllium isotope 10
Be, detected in Antarctic ice cores, has also been associated with the 774–775 event. The 774–775 CE carbon-14 spike is one of several Miyake events and it produced the largest and most rapid rise in carbon-14 ever recorded.
Christopher Bronk Ramsey is a British physicist, mathematician and specialist in radiocarbon dating. He is a professor at the University of Oxford and was the Director of the Research Laboratory for Archaeology and the History of Art (RLAHA) from 2014 until 2019. He is a member of Merton College, Oxford and a Bodley Fellow. His doctorate, completed in 1987, included the first successful implementation of carbon dioxide gas as a target for radiocarbon dating via accelerator mass spectrometry.
Lake Suigetsu is a lake in the Hokuriku region of Honshu, Japan, which is one of the Mikata Five Lakes located in Mihama and Wakasa, Fukui Prefecture, close to the coast of the Wakasa Bay in the Sea of Japan. Since 1993, it has been attracting the attention of scientists because of the undisturbed nature of the water for many thousands of years. It is possible to identify the annual deposits of silt in a similar manner that tree rings are identified.
Minze Stuiver was a Dutch geochemist who was at the forefront of geoscience research from the 1960s until his retirement in 1998. He helped transform radiocarbon dating from a simple tool for archaeology and geology to a precise technique with applications in solar physics, oceanography, geochemistry, and carbon dynamics. Minze Stuiver's research encompassed the use of radiocarbon (14C) to understand solar cycles and radiocarbon production, ocean circulation, lake carbon dynamics and archaeology as well as the use of stable isotopes to document past climate changes.
Radiocarbon dating measurements produce ages in "radiocarbon years", which must be converted to calendar ages by a process called calibration. Calibration is needed because the atmospheric 14
C:12
C ratio, which is a key element in calculating radiocarbon ages, has not been constant historically.
Thomas F. G. Higham is an archaeological scientist and radiocarbon dating specialist. He has worked as Professor of Archaeological Science at the University of Oxford, UK, where he was the Director of the Oxford Radiocarbon Accelerator Unit (ORAU) in the Research Lab for Archaeology and the History of Art. He is best known for his work in dating the Neanderthal extinction and the arrival of modern humans in Europe. He is Professor in the Department of Evolutionary Anthropology at the University of Vienna.
Edouard Bard, born on September 1, 1962, is a French climatologist, Professor of Climate and Ocean Evolution at the Collège de France and a member of the French Academy of Sciences.
Fusa Miyake is a cosmic ray physicist at Nagoya University, Japan, whose work measuring isotope abundances led to recognition of so-called Miyake events. These have resulted in reconciling differences between dates from documents and materials such as ice-cores and tree rings.
