Sunday, December 17, 2006

A blast from the past
I'm always amazed at how much data there is to be squeezed out of the ice. A team in Antarctica is taking the first steps toward reconstructing ancient wind patterns on the white continent.
US scientists have reconstructed a 40,000-year record of wind conditions at the South Pole.

They assembled the climate data by measuring the distribution of dust layers seen in two ice boreholes.

A comparison of the layers allowed the University of California-Berkeley team to gauge how rough snow surfaces would have been in ancient times.

The researchers then used this "proxy" to assess the probable strength of wind needed to produce those features.

The technique needs refinement and works best in the deeper parts of the ice. Nonetheless, scientists are confident it gives at least a broad record of conditions at the pole some 30,000 to 70,000 years ago.

And if combined with a number of palaeo-wind records gathered from around the continent, it could provide a useful tool to test climate computer models, they believe.

Two holes aren’t going to allow for much reconstruction. They will need to drill hundreds of holes all over the continent to map wind patterns. Once they have collected the data, it will be available for dozens of fields. They talk of testing modern weather models, but I can see this data being useful for all kinds of earth sciences as well as paleontology and normal history.

Dendrochronology--dating with tree rings--was originally thought of merely as a method of dating wooden artifacts. But once the data had been gathered to create chronologies of different types of wood in different locations, other fields took the data and used it to recreate historical climates and ecologies. These recreations allowed still other fields to test theories of population growth and migration. Data from the ice is the same.

One of the side tragedies of our current blind attitude toward global warming is that every glacier that disappears takes the equivalent of a major library full of scientific and historical data with it. Ever if everything turns ot fine future generations of scholars will condemn our decades for having burned a hundred libraries of Alexandria.

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