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Ocean Cores
12/10/2002
Listen in RealAudio 
Hi, I'm Bryan Yeaton and this is The Weather Notebook's weekly segment on global climate
change. A team of 28 researchers from across the globe have discovered, through ocean coring,
the first-ever continuous record of climatic conditions 50 million years ago. Jeff Rice
reports.
Think of it as a floating telescope.
ML: The drill ship is an observatory just the way the Hubble space telescope is an
observatory.
Out in the middle of the Pacific Ocean, paleooceanographers like Dr. Mitch
Lyle of Boise State University are able to peer back millions of years by
drilling into the mud on the ocean floor.
Lyle is especially interested in the Eocene, a time 50 million years ago
when there were no polar ice caps on earth. There were forests growing in
Antarctica...
ML: And actually, there were crocodiles and palm trees in Wyoming.
The ocean sediments hold the answers to many key questions about the earth's
changing climate. Scientists can tell things like wind patterns from dust
distribution. They can look at fossilized plankton to gauge the earth's
temperatures. But it's no easy trick, as Lyle experienced on a recent
drilling expedition in the Pacific.
ML: We were working in 15,000, 16,000 feet of water, so if something stuck in
the end of the pipe it meant 24 hours to pull everything up.
Scientists will typically spend two months at sea gathering soil samples at
a cost of $50,000 a day. Ocean drilling differs from its cousin, ice coring,
because it allows scientists to look much farther back in the geologic
record.
ML: The basic reason is soil doesn't melt.
By looking at conditions from extremely warm periods like the Eocene,
scientists are hoping to create more accurate models of current global
warming trends.
Jeff Rice comes to us from Idaho. Our series on global climate change is supported by the New
England Science Center Collaborative and the Roy A. Hunt Foundation.
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