Thursday, June 21, 2007

The Long View on Climate and Levels in the Great Lakes

The Chicago Tribune is a great paper. Take some time to settle in with this well done piece.

From today's Great Lakes' past may offer clues on climate, an excerpt:

"During periods of low water that lasted until 2,000 years ago, a forest stood at the bottom of Duluth harbor and in parts of Lake Huron. Peat bogs stretched between what are now the Apostles Islands near Wisconsin. At a bay above Sault Ste. Marie, Mich., successive underwater ridges were a thriving forest when Leif Ericson landed in North America, and an active beach later in dry spells as recent as the 1700s. In Lake Michigan, salvage divers in the 1980s found a grove of sunken tree trunks 15 miles off Navy Pier that date back thousands of years.

Piecing together those clues, climate detectives suspect Lakes Superior, Michigan and Huron may have been lower than 20th Century historical averages in the 13th and 17th Centuries and much higher in the 16th Century as well as over the last 50 years."

Thank you,
James Janega, for writing this article.