Tales from Ice Time

Text by: Richard Monastersky
© Science News, Vol 140, 1991

The scene evokes images of surgeons performing a liver transplant in full football gear.

Moving quickly but gingerly, a crew of heavily outfitted drillers coaxes a long icicle from its container and hurries the glistening prize to a dumbwaiter. Room temperature here hovers at a dangerously warm level, only 10 degree C below freezing, and the crew must lower the ice as fast as possible into the safety of a cold snow cellar. They take care not to slip, though. The chunk of frozen water they hold is valued at more than $30,000.

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From the vantage point of the GISP 2 campt, ti's not hard to imagine Earth as it was 18,000 years ago, during the coldest stage of the last ice age.

GISP 2 scientists spend their summers in a flat, frozen world some 650 kilometeres north of the Arctic Circle, near the highest part of the immmense ice sheet blanketing more than 80 percent of Greenland. Beyond the scattered buildings and tents, a white plain stretches in every direction toward unbroken horizons. On an overcast day, sky and snow wear the same dull hue, creating a featureless void that seemes to go on forever.

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This is how Denmark or Detroit must have looked during the lst ice age, when thick glacial sheets covered much of Europe, Asia and North America. In the United States, the glaciers reached as far south as St. Louis in the heartland and Long Island in the east. Though the ice retreated from most parts of the globe by about 10,000 years ago, it still maintains a grip on Antarctica and Greenland.

The ices sheet beneath the GISP 2 camp measures more than 3 kiometers deep - a load so heavy it has warped the bedrock on which it rests. Save for parts