Saturday, July 13, 2013

Ingesting the ice

I found out several years ago that it was typical of French-American naturalist John James Audubon to eat the specimens he drew, but I only learned recently that it is a long-standing tradition among scientists to sample what they study. The entomologists, of course, get the most press! But scientists who study ancient ice cores also taste their research subject. When they are in the field, the only source of fresh water might be the Antarctic glacier on which they are camped. But they are driven by more than just necessity. They use broken pieces in their drinks and they fizz as they melt because of compressed gas bubbles inside. And they have even been known to use the ice to hold their drinks: "I actually made drinking glasses out of 40,000-year-old ice by hollowing out the inside of a waste core, a byproduct of the sampling we did," says geoscientist Ed Brook of Oregon State University. Ancient ice is - on the whole - fresh and pure, having lost most of its impurities through pressure squeezing. But it is miniscule amounts of metals in it that give scientists like Paolo Gabrielli (pictured above in the cold storage facility at Ohio State University's Byrd Polar Research Center) clues about past environmental conditions. These trace and ultra-trace elements, carried to the ice mainly by dust, can include lead, mercury, and platinum. Other contaminants like lead and mercury can also be found in polar ice cores. But it is elements leached from the surrounding rock that gave 2.6 billion-year-old water its taste – and its discoverer did follow tradition and taste it! Earth scientist Barbara Sherwood Lollar of the University of Toronto critiques the ancient agua: "What jumps out at you first is the saltiness. Because of the reactions between the water and the rock, it is extremely salty. It is more viscous than tap water. It has the consistency of a very light maple syrup. It doesn't have color when it comes out, but as soon as it comes into contact with oxygen it turns an orangy color because the minerals in it begin to form - especially the iron....It tastes terrible. It is much saltier than seawater. You would definitely not want to drink this stuff."

No comments:

Post a Comment

You may add your comments here.