Evidence for European presence in the Americas in AD 1021

The question of when Europeans first reached the Americas has long been a subject of debate. While the Viking presence at L'Anse aux Meadows in Newfoundland is confirmed, the precise timing of this activity remained elusive. Previous attempts at dating, primarily relying on stylistic analysis of artifacts and sagas, yielded imprecise results. Radiocarbon dating efforts, though numerous, suffered from limitations in technology and methodology, producing wide chronological ranges. This study aimed to overcome these limitations by employing an advanced chronometric approach to precisely pinpoint the date of Norse activity at L'Anse aux Meadows.

Existing literature on the Norse presence in North America primarily focuses on the L'Anse aux Meadows site. Extensive archaeological work has provided insights into the settlement's structure and environment. However, accurate dating has been hampered by inconsistent radiocarbon results, with existing dates spanning the entire Viking Age (AD 793-1066). These inconsistencies stem from limitations in the 1960s and 70s radiocarbon technology, including greater measurement uncertainty and the issue of 'inbuilt age'—the difference between the age of the sample and the organism's death. Icelandic sagas offer some information but are written centuries after the events, introducing potential biases and differing interpretations regarding the frequency and duration of Norse activity in the Americas.

This study utilized high-precision accelerator mass spectrometry (AMS) in conjunction with the distinctive features of the atmospheric 14C record to achieve exact-year dating. The researchers focused on the rapid increase in 14C production in AD 993, a globally synchronous event caused by cosmic radiation. Three wooden artifacts from L'Anse aux Meadows, demonstrably modified by Norse tools, were analyzed. The method involved two steps: first, wiggle-matching the 14C data against the Northern Hemisphere calibration curve to determine the range of possible dates for the waney edges (the outer edge of the tree trunk); second, using the classical χ² approach to match the 14C data from rings likely to contain the AD 993 anomaly against a high-resolution reference dataset (B2018). This precise pattern matching allowed for the determination of the exact felling year of each tree. Wood taxonomy was also conducted to determine species and aid in dating.

The analysis of three different wood samples from L'Anse aux Meadows, all modified by Norse tools, converged on the same felling year: AD 1021. The 14C dates from the outermost rings of these samples, precisely matched to the AD 993 anomaly, consistently pointed to this year. The researchers found the modification of the wood to be highly unlikely before or after AD 1021 due to the presence of the AD 993 anomaly and the preservation of the waney edge, ruling out the possibility of driftwood or later scavenging. This date represents the first secure calendar date for the European presence across the Atlantic before Columbus, indicating Norse activity in North America in AD 1021.

The finding of AD 1021 as the date of Norse activity at L'Anse aux Meadows directly addresses the long-standing uncertainty surrounding the precise timing of European contact with North America. This precise date provides a definitive chronological anchor for future research into the consequences of transatlantic activity by the Norse, including potential cultural exchanges, pathogen transmission, introduction of foreign species, and human genetic information exchange. The convergence of three independent wood samples on the same year strengthens the reliability of the findings, highlighting the power of the AD 993 14C anomaly as a precise dating tool.

This study provides compelling evidence for Norse activity at L'Anse aux Meadows in AD 1021. This precise date offers a secure juncture for late Viking chronology and acts as a new point of reference for understanding early transatlantic contacts. Future research should explore further the implications of this discovery in understanding cultural exchange, genetic interaction, and the broader context of early human global migration.

While the study successfully provided a precise date for Norse presence at L'Anse aux Meadows, it focuses on a single site. Further research is needed to determine whether this date reflects a single short-lived visit or a more extended period of Norse activity. Additionally, potential environmental factors that could have affected the preservation or analysis of the wooden samples warrant further investigation.