An analysis of tooth enamel from Viking settlements in Greenland has found evidence of the temperature drop thought to have led to the settlers' demise around 1500, researchers say.
The cooling trend detected by way of the teeth coincides with Northern Europe's Little Ice Age, which according to historical records lasted from 1300 to 1500.
Scientists drew their conclusions from the ratio of different types of oxygen atoms in teeth of Norse settlers and Eskimos living along the Greenland coast between 1100 and 1500.
The tooth enamel technique could provide a means of "determining temperature changes in continental areas wherever and whenever human remains are found," said Henry C. Fricke, a University of Michigan geochemistry student.
Paul Koch, a professor of geological and geophysical sciences at Princeton University, said: "It's a good finding. It's unique, I think, in trying to reconstruct paleoclimate using human fossil remains." He said the technique can show temperature trends, although "they're not yet at a state to reconstruct actual temperatures from it."
The Michigan team examined oxygen contained in calcium phosphate from 29 human teeth taken from three archaeological sites in Greenland and one in Denmark. They measured the ratio of heavier oxygen atoms, or isotopes, to lighter oxygen isotopes.
The ratio in teeth mirrors the oxygen isotope composition of local …