Wood from the Netherlands around the time of the Santorini eruption dated by dendrochronology and radiocarbon

Eighteen new high-precision radiocarbon (C) dates obtained for dendrochronologically dated wood from Bodegraven, the Netherlands are reported. They are relevant for establishing the revised calibration curve around the time of the Bronze Age Santorini eruption. Most of our new data overlap within one sigma with IntCal13, but a few data points are slightly increased in C age compared to IntCal13

CHRONOscope: application for the interactive visualization of carbon-14 and beryllium-10 atmospheric data

Information about the global climate, the carbon cycle, changes in solar activity, and a number of other atmospheric processes are preserved in the carbon-14 and the beryllium-10 records. However, these isotope datasets are large and cumbersome to work with. We have designed a self-contained, easy-to-use application that allows for more efficient analysis of different periods and patterns of interest. For several applications in atmospheric modelling, a pre-processing stage is applied to the isotope datasets in order to interpolate the data and mitigate their low temporal resolution. In CHRONOscope, we included linear and non-linear methods of interpolation with interactive parameter optimization. The resultant interpolated data can be extracted for further use. The main functionalities of CHRONOscope include the importation and superimposition of external data, quick navigation through the data with the use of markers, expression of the carbon-14 results in both Δ14C and yr BP form, separation of the data by source, and the visualization of associated error bars. We make this free software available in standalone applications for both Windows and Mac operating systems

Radiocarbon-based investigations into the authenticity of Mesoamerican artefacts in museum contexts

In this article, radiocarbon dating has been used as a tool for investigating the authenticity of two Mesoamerican artefacts from the collection of the National Museum of World Cultures (Museum Volkenkunde), Leiden, the Netherlands. The first artefact is a ceremonial Aztec, possibly a tecpatl, knife, and it is presumed to date to 1300–1500 CE. The second object is a decorated Mixtec skull, presumed to date to 1400–1520 CE. The efficacy of radiocarbon dating was thoroughly tested in this study, especially in regard to the tiny quantities that could be sampled from the skull. However, with the newly revamped radiocarbon facility at the University of Groningen, this was an opportune moment to attempt such research.  Ultimately, a credible result could not be obtained on the skull; however, the ceremonial knife was dated reliably to the Aztec period. The article also discusses the broader issue of whether radiocarbon results can be used as a definitive proof of authenticity and examines the risk-reward nature of radiocarbon testing

Trainable Filters for the Identification of Anomalies in Cosmogenic Isotope Data

Extreme bursts of radiation from space result in rapid increases in the concentration of radiocarbon in the atmosphere. Such rises, known as Miyake Events, can be detected through the measurement of radiocarbon in dendrochronological archives. The identification of Miyake Events is important because radiation impacts of this magnitude pose an existential threat to satellite communications and aeronautical avionics and may even be detrimental to human health. However, at present, radiocarbon measurements on tree-ring archives are generally only available at decadal resolution, which smooths out the effect of a possible radiation burst. The Miyake Events discovered so far, in tree-rings from the years 3372-3371 BCE, 774-775 CE, and 993-994 CE, have essentially been found by chance, but there may be more. In this paper, we use signal processing techniques, in particular COSFIRE, to train filters with data on annual changes in radiocarbon (Delta C-14) around those dates. Then, we evaluate the trained filters and attempt to detect similar Miyake Events in the past. The method that we propose is promising, since it identifies the known Miyake Events at a relatively low false positive rate. Using the findings of this paper, we propose a list of 26 calendar years that our system persistently indicates are Miyake Event-like. We are currently examining a short-list of five of the newly identified dates and intend to perform single-year radiocarbon measurements over them. Signal processing techniques, such as COSFIRE filters, can be used as guidance tools since they are able to identify similar patterns of interest, even if they vary in time or in amplitude

Radiocarbon-based approach capable of subannual precision resolves the origins of the site of Por-Bajin

Inadequate resolution is the principal limitation of radiocarbon dating. However, recent work has shown that exact-year precision is attainable if use can be made of past increases in atmospheric radiocarbon concentration or so-called Miyake events. Here, this nascent method is applied to an archaeological site of previously unknown age. We locate the distinctive radiocarbon signal of the year 775 common era (CE) in wood from the base of the Uyghur monument of Por-Bajin in Russia. Our analysis shows that the construction of Por-Bajin started in the summer of 777 CE, a foundation date that resolves decades of debate and allows the origin and purpose of the building to be established

Evidence for European presence in the Americas in ad 1021

Transatlantic exploration took place centuries before the crossing of Columbus. Physical evidence for early European presence in the Americas can be found in Newfoundland, Canada(1,2). However, it has thus far not been possible to determine when this activity took place(3–5). Here we provide evidence that the Vikings were present in Newfoundland in ad 1021. We overcome the imprecision of previous age estimates by making use of the cosmic-ray-induced upsurge in atmospheric radiocarbon concentrations in ad 993 (ref. (6)). Our new date lays down a marker for European cognisance of the Americas, and represents the first known point at which humans encircled the globe. It also provides a definitive tie point for future research into the initial consequences of transatlantic activity, such as the transference of knowledge, and the potential exchange of genetic information, biota and pathologies(7,8)

Elasmotherium Sibiricum: De uitgestorven Siberische eenhoorn – uitkomsten van opzienbarend onderzoek

In februari werd in het gerenommeerde archeologische tijdschrift Antiquity een artikel gepubliceerd over de oudste mens van Nederland en de oudste kunst uit de Noordzee (Amkreutz et al. 2018). Beide vondsten zijn meer dan 13.000 jaar oud. Ze zijn uiterst zeldzame aanwijzingen voor de herbewoning van noordelijk Europa door de moderne mens na de kou van het laatste glaciale maximum van de laatste ijstijd. Deze bijdrage is een samenvatting van het betreffende artikel