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Lake Champlain's Two Seiches

The main body of Lake Champlain is 117 kilometers long, with an average breadth of 6.3 kilometers, and average depth of 29 meters. Although its shoreline in complex, there is a deep channel about 2 kilometers wide with steep sides running lengthwise along the lake floor.

When wind blows across the lake's surface, wind-drag pushes surface water downwind. When the wind stops or changes direction, the piled-up water is freed, and standing waves are set up as the water sloshes back and forth in the lake basin. These waves are called "seiches." Lakes usually have characteristic periods of oscillation. For Lake Champlain, it is 4 hours, with amplitudes measured only in centimeters on the surface of the water.

What makes Lake Champlain of more than usual interest is the presence of a second seiche, an internal phenomenon not visible on the surface. In the summer, Lake Champlain is stratified with a thermocline separating a layer of warm surface water from much colder deep water. You can only "see" the thermocline if you lower a thermometer into the water. This thermocline also exhibits seiches, but they are startlingly different from those on the surface. In Lake Champlain, the period of the internal seiche is 4 days rather than 4 hours. The amplitudes fall between 20 and 40 meters instead of being in the centimeter range. Just a few meters below the lake's surface, conditions are radically different.

(Hunkins, Kenneth, et al; "Numerical Studies of the 4-Day Oscillation of Lake Champlain," Journal of Geophysical Re search, 103:18,425, 1998.)

Seiches of Lake Champlain The seiches under discussion occur in the main part of Lake Champlain on the left.

From Science Frontiers #121, JAN-FEB 1999. 1999-2000 William R. Corliss

Science Frontiers Sourcebook Project Reviewed in:

Quotes

  • "A sourcebook of unexplained phenomena is therefore a valuable addition to a collection of scientific literature. William R. Corliss has provided this in the past with his source books of scientific anomalies in several subjects, and now he has provided it for astronomy. He has done an excellent job of collecting and editing a large amount of material, taken in part from scientific journals and in part from scientific reporting in the popular or semi-scientific press." -- "The Mysterious Universe: A Handbook of Astronomical Anomalies", reviwed by Thomas Gold, Cornell University, in Icarus, vol.41, 1980

  • "An interesting, systematic presentation of unusual weather [..] This book is recommended for a general audience" --"Corliss, William R., Tornados, Dark Days, Anomalous Precipitation, and Related Weather Phenomena, Sourcebook Project, 1983.", revieweed in Choice, September 1983
  • "..the science is necessarily somewhat speculative, but Corliss's symthesis is based on reputable sources." -- "Corliss, William R. (Compiler). Lightning, Auroras, Nocturnal Lights, and Related Luminous Phenomena" reviwed by Joseph M. Moran, Univ. of Wisconsin in Science Books and Films, Sep/Oct 1983

  • "Before opening the book, I set certain standards that a volume which treads into dangerous grounds grounds like this must meet. The author scrupulously met, or even exceeded those standards. Each phenomenon is exhaustively documented, with references to scientific journals [..] and extensive quotations" -- "Book Review: The moon and planets: a catalog of astronomical anomalies", The Sourcebook Project, 1985., Corliss, W. R., Journal of the Royal Astronomical Society of Canada, Vol. 81, no. 1 (1987), p. 24., 02/1987