Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, October 27, 1994 TAG: 9410280014
SECTION: NATIONAL/INTERNATIONAL PAGE: A-11 EDITION: METRO
SOURCE: Associated Press
DATELINE: SEATTLE LENGTH: Medium
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 technique could provide a means of ``determining temperature changes in continental areas wherever and whenever human remains are found,'' said Henry Fricke, a University of Michigan geochemistry student.
He presented his findings Tuesday at the annual meeting of the Geological Society of America.
``It's a good finding. It's unique, I think, in trying to reconstruct paleoclimate using human fossil remains,'' said Paul Koch, a professor of geological and geophysical sciences at Princeton University.
The technique is good at showing temperature trends, but ``they're not yet at a state to reconstruct actual temperatures from it,'' Koch said.
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 rainfall and snowfall, since oxygen is incorporated in the forming teeth of children, the researchers said. The colder the climate, the less of the heavier oxygen isotope is contained in precipitation.
Fricke said it would be misleading to say that temperature change alone led to the demise of the Viking settlements. ``More likely it's a combination of temperature change and economics,'' he said.
by CNB