from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun An intermediate layer of oceanic water in which temperature decreases more rapidly with depth than in the layers above and below it.
  • noun A layer in a large body of water, such as a lake, that sharply separates regions differing in temperature, so that the temperature gradient across the layer is abrupt.

from The Century Dictionary.

  • noun A layer within a large body of water sharply separating portions of it which differ in temperature, so that the temperature-gradient through the layer is very abrupt.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun geography A layer within a body of water or air where the temperature changes rapidly with depth.


from Wiktionary, Creative Commons Attribution/Share-Alike License

thermo- + -cline


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  • In between the two layers, there is a narrow zone called the thermocline where the temperature of the water changes rapidly.

    Freshwater biomes 2007

  • The thin yellow line is probably the thermocline, which is the place where the warm water and cold water meet.

    Road Map #3 « Climate Audit 2006

  • The ocean is not really one ocean, but two -- a top and bottom layer, with a boundary layer approximately one kilometer below the ocean surface, called the thermocline, through which very little vertical transport takes place.

    Analog Science Fiction and Fact 2003

  • The thermocline was a tricky bitch, one that worked both for you and against you, Pencehaven reflected.

    Joint Operations Douglass, Keith 2000

  • Coccolithophore blooms often develop during the summer when a blanket of water called the thermocline develops between the upper mixed layer above and the deep water below.

    R&D Mag - News 2010

  • The thermocline is the layer of increasingly colder water that separates the warmer surface layer from the colder deep water. - News 2009

  • When deployed in the open ocean, the tube would hang vertically, descending through the warm, well-mixed upper reaches of the ocean and terminating in a deeper part of the water column known as the thermocline, where water temperatures drop precipitously.

    Scientific American 2009

  • a blanket of water called the thermocline develops between the upper mixed layer above and the deep water below. - latest science and technology news stories 2010

  • a blanket of water called the thermocline develops between the upper mixed layer above and the deep water below. - latest science and technology news stories 2010

  • If you are fishing for kings, fish where the thermocline hits bottom because that is where the elewives will be.

    Whats the best lure and depth for trolling in Lake Michigan right now? 2009


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  • "Fish are not distributed equally throughout the water column; they congregate in certain areas. You have to know where those areas are. You generally set westward into the current. With a thermocline scope you get temperature readings at different depths; with a Doppler you get the velocity and direction of subsurface currents at three different levels...."

    —Sebastian Junger, The Perfect Storm, 1997 (NY: HarperCollins, 1999), 57

    August 19, 2009

  • How are you liking this book, c_b? I enjoyed it, but don't bother seeing the movie version (unless it's too late).

    August 20, 2009

  • I saw the movie in the theaters, ages ago. Just read the book. Actually finished it some days ago, just haven't had much time to add words.

    It's a good book. I think they might have been nuts to try to make a movie out of it. Perhaps I'll have to see it again to be sure as I don't remember much about it. Naturally I learned far more from the book than from the movie, but that's to be expected.

    August 20, 2009

  • I can't stand the movie - partly because it's a lame movie and partly because I've seen it about a dozen times - but I'm enjoying the book extracts and might take a gander at it one day.

    August 20, 2009

  • Oh, the book is far better than the movie. I had the same reaction (read the book first) when I saw it--why did they bother? As I recall, I was disappointed by the fact that the movie included so much romantic drivel and so little about the event that caused the author to write the book in the first place.

    August 20, 2009

  • It is a good book, yarb. Particularly if you're interested in commercial fishing.

    ... that sounded really odd.

    August 20, 2009