A Cosmic Ray Event Pinpoints the Viking Landing in Canada

The LAnse aux Meadows archeological location on Newfoundland's island is not very appealing to the untrained eye. It has been a UNESCO World Heritage Site since 1978. Although the reconstructed Viking huts, and workshops, are charmingly photogenic, they are still reconstructions. The only thing that is left of the original buildings are the remnants of timber-andturf structures. These have been covered with lush grass. The site is modest, but it represents an important moment in history. It is evidence that Europeans crossed the Atlantic five centuries prior to Columbus. While scholars debate the route the Vikings traveled or the reasons they arrived at these shores, researchers now know when they were there. A new study has placed the Vikings here in AD 1021exactly 1000 years ago.
Although the LAnse aux Meadows site has been studied since 1960s, it was only possible to make rough estimates of its age. Radiocarbon dating was still in its infancy at the time of first study, and results were not always reliable. A new technique, which uses astrophysics to aid archeology, has given the process a greater level of precision.

This technique relies on a cosmic radiation event, which is a burst or ejection of energy particles from space, similar to the one that hit Earth's atmosphere in late 10th century AD. According to Michael Dee, a geophysicist, archeologist, and geophysicist at the University of Groningen, the sun sent out a huge bursteither a solar flareor a coronal mass eruptionof highly energetic particles in 992. The barrage of particles that hit the atmosphere caused the production of carbon-14. This radioactive isotope was then absorbed by plants all over the globe in the year 19993.

Carbon-12, which has six protons, six neutrons and accounts for around 99 percent of the carbon on Earth, is slightly heavier than carbon-13 with an additional neutron accounting for approximately 1 percent. Carbon-14, which contains two additional neutrons and radioactive, is only found in trace amounts. It accounts for approximately one in every trillion carbon atoms. The authors claim that carbon-14 levels rose by 12 percent due to the solar eruption. If trees were alive at the time, they contain a ring that records this carbon-14 increase. If you are lucky enough to find wood that comes from a tree that survived one of these extreme solar storms, simply count from the ring where the spike was measured to its edge to determine when it was felled.