> Consequently, more radiocarbon is packed into a single growth ring, and scientists can determine the exact year that ring was built. They can then count to th

> Consequently, more radiocarbon is packed into a single growth ring, and scientists can determine the exact year that ring was built. They can then count to the outer ring of the tree to know the year that it died. The article somewhat confused the details. To determine the exact year the ring was built (and subsequently year the tree died) scientists look at the growth pattern of the surrounding rings and compare them with a reference data set of ring width of the same tree species in the same (wider) area. This works even if the outer ring is not present. The outer ring is only relevant if we want to determine the exact year a tree had been cut down, which is important for archaeology but not to establish the date of the Miyake event in the first place. > ... providing definitive evidence that the Vikings beat Columbus to North America. > ... The researchers speculated that the settlement was built sometime near the end of the first millennium This was no "speculation", but has already been established as a fact for decades with the excavation of the settlement of L’Anse aux Meadows itself in the early 1960s. Tree ring dating only helped to identify the specific date of the settlement in the already established time frame, because the only fitting Miyake event was that of 992/993. (The article mentions this, but the chain of reasoning is not really accurate.) The problem with determining the exact date of the settlement without the reference to the Miyake event was that we do not have a reference record for the tree rings at this site, as this requires an uninterrupted record of overlapping trees from the present back to the Viking Age for these particular timber species in the area. This could perhaps been established with a lot of effort over the years, but with the Miyake events we have indeed a very interesting method to compile reference records even without a complete reference record to the present. However, it still remains uncertain, for example, to which Miyake event a particular piece of wood should be attributed without much context, whether we already know all the Miyake events of the last couple of millennia, and whether another, more local event could have led to a carbon-14 value that could be confused with a global Miyake event.