Great Lakes Losing Their Water

Water levels in Lake Michigan have recently dropped beneath record monthly lows, heightening Great Lakes water level concerns. The readings did not set a new record, as not daily measurements but monthly averages are the determinant, but the level could set an official record by month's end if rain and snowfall do not deliver.

"This is the closest we've been to the record in a while," said Cynthia Sellinger, deputy director of the Great Lakes Environmental Research Laboratory, Ann Arbor, Mich., run by the National Oceanic and Atmospheric Association. "Lake Michigan has been dropping continuously since 1997, and it's finally approaching the record lows."

Lake Michigan's water level entered 2008 at a level of 576.3 ft, 13 in. below where it was one year ago and more than 2 ft below average for the month of December. Lake researchers expect the year's lowest water levels to come in spring based on ebb and flow; even slight deviations from predicted January and February precipitation could trigger an early drop.

Possible explanations have ranged from warmer winters and drier summers to the unintended consequences of dredging rivers between the lakes in the 1960s. Another idea that has been posed is that the Earth's crust is lifting as glaciers melt, allowing water to drain from the lakes more speedily.

Source: Chicago Tribune