Which explains why it takes several hundred years for a complete turn over, which probably happens for two brief periods each year when the entire lake is at 4C.
Canada’s Only True Desert
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Which explains why it takes several hundred years for a complete turn over, which probably happens for two brief periods each year when the entire lake is at 4C.
Here is a nice article on lake turnover for all those arguing the point should read......
Lake Superior's Natural Processes | Minnesota Sea Grant
Water's tricky and unusual property — the one that enables lakes to stratify — is density. Water is most dense, and therefore heaviest, at 3.94°C (39.2°F). Thermal layers begin to form in July as Superior's surface waters warm beyond 3.94°C. The sun-warmed lighter water in the epilimnion layer becomes separated from the denser water in the hypolimnion layer by a transition zone where the temperature of the water column changes sharply (the thermocline, also know as the metalimnion). The thermocline creates a thermal barrier between the surface and bottom waters. In Lake Superior the summer thermocline hovers around 30 meters deep, in part due to water clarity and wind.
Stratification becomes more pronounced and deeper as Lake Superior's surface warms to a September high. As the winter solstice approaches and the buoyant surface waters cool, the density between layers becomes increasingly similar. When the density is similar enough, a windstorm can mix the entire lake. This sinking of heavy water and mixing by wind results in the exchange of surface and bottom waters, an event referred to as lake turnover. Global climate patterns influence the timing of the lake's turnover. Turnover is enormously important for redistributing nutrients and oxygen within the water column. The lake is thought to mix rather completely until the surface waters cool enough to show negative stratification, a condition in which positively frigid water (0-3.93°C) lies above very cold water. This period of stratification breaks down in June, after the returning sun has warmed the surface water back to 3.94°C and its maximum density 1.000 gm/ml. This is when spring turnover occurs.
Anyone who has worked with the M.N.R.to poison a lake in order to introduce a new specie such as trout is familiar with lake turnover twice a year because it is easier to distribute the chemical throughout the whole lake...top to bottom at that time...
That would be most every members of the "rod and gun club" here in town
Lake Superior's Natural Processes | Minnesota Sea Grant
Water's tricky and unusual property — the one that enables lakes to stratify — is density. Water is most dense, and therefore heaviest, at 3.94°C (39.2°F). Thermal layers begin to form in July as Superior's surface waters warm beyond 3.94°C. The sun-warmed lighter water in the epilimnion layer becomes separated from the denser water in the hypolimnion layer by a transition zone where the temperature of the water column changes sharply (the thermocline, also know as the metalimnion). The thermocline creates a thermal barrier between the surface and bottom waters. In Lake Superior the summer thermocline hovers around 30 meters deep, in part due to water clarity and wind.
Stratification becomes more pronounced and deeper as Lake Superior's surface warms to a September high. As the winter solstice approaches and the buoyant surface waters cool, the density between layers becomes increasingly similar. When the density is similar enough, a windstorm can mix the entire lake. This sinking of heavy water and mixing by wind results in the exchange of surface and bottom waters, an event referred to as lake turnover. Global climate patterns influence the timing of the lake's turnover. Turnover is enormously important for redistributing nutrients and oxygen within the water column. The lake is thought to mix rather completely until the surface waters cool enough to show negative stratification, a condition in which positively frigid water (0-3.93°C) lies above very cold water. This period of stratification breaks down in June, after the returning sun has warmed the surface water back to 3.94°C and its maximum density 1.000 gm/ml. This is when spring turnover occurs.
Anyone who has worked with the M.N.R.to poison a lake in order to introduce a new specie such as trout is familiar with lake turnover twice a year because it is easier to distribute the chemical throughout the whole lake...top to bottom at that time...
That would be most every members of the "rod and gun club" here in town
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If you are talking about me, I haven't said boo about "global warming" except to say that we are still emerging from the last glacial period. I suppose, in one sense, I did mention it indirectly. Do you actually disagree that we are still emerging from the last great glaciation? (Hint: Obama, Suzuki, Gore are not involved. It is not political. It is a scientific truth, I'm afraid, that we are still thawing out after the last glaciation.)
Is your tea-trolley mind keeping up?
Do you talk the way the you write up in them thar hills?
Did the Revenooers bust up your still, Cletis?
Alpine glaciers reached their maximum extent within the past 500 years. They are perpetually shrinking and growing. We have a long way to go to parallel the losses of the past. Hydro dams rely on winter snow pack to refill every spring not glaciers.
I would have thought that they reached their peak about 20,000 years ago when they were component of the great continental glaciers that have gradually receded (still receding in Greenland, Antarctica, the Arctic Archipelago. )
So, if they only just peaked 500 years ago, presumably they weren't around much before that, they they got bigger and peaked recently.
Boy, I'd like to see that link. I suppose,if you believe in Noah's flood, ...
What he means is that over the long term since the last ice age the glaciers have been retreating, but as they retreat, they ebb and flow. They shrank down 1000 years ago, than grew for a few hundred year, and now they're back to shrinking.
More importantly, Hydro dams rely on snow pack not melting glaciers. You have been caught so many times making up stories on the fly, and not once have I seen you admit that you were wrong. Now's an opportunity for you to amaze the world by making a small confession.
No, I still believe that you are using up a finite resource and that large cities in semi-deserts are not sustainable.
Reservoirs...
Most alpine glaciers in the Northern Hemisphere reached their maximum extents of the Holocene between AD 1600 and 1850. Since the late 1800s, however, glaciers have thinned and retreated, mainly because of atmospheric warming. Glacier retreat in western Canada and other regions is exposing subfossil tree stumps, soils and plant detritus that, until recently, were beneath tens to hundreds of metres of ice. In addition, human artefacts and caribou dung are emerging from permanent snow patches many thousands of years after they were entombed. Dating of these materials indicates that many of these glaciers and snow patches are smaller today than at any time in the past several thousand years. This evidence, in turn, suggests that glacier recession in the 20th century is unprecedented during the past several millennia and that glaciers in western Canada have reached minimum extents only 150–300 years after they achieved their maximum Holocene extents.
INCOMING!!!!
Most alpine glaciers in the Northern Hemisphere reached their maximum extents of the Holocene between AD 1600 and 1850. Since the late 1800s, however, glaciers have thinned and retreated, mainly because of atmospheric warming. Glacier retreat in western Canada and other regions is exposing subfossil tree stumps, soils and plant detritus that, until recently, were beneath tens to hundreds of metres of ice. In addition, human artefacts and caribou dung are emerging from permanent snow patches many thousands of years after they were entombed. Dating of these materials indicates that many of these glaciers and snow patches are smaller today than at any time in the past several thousand years. This evidence, in turn, suggests that glacier recession in the 20th century is unprecedented during the past several millennia and that glaciers in western Canada have reached minimum extents only 150–300 years after they achieved their maximum Holocene extents.
Decaying Uranium atoms ...
produce half of the electricity that I consume. A big part of the rest comes from the height difference between Lake Erie and Lake Ontario.
Man-made reservoirs have finite and relatively short life spans. They silt up pretty quickly and a century or so is about the lifespan of a reservoir.
It is the shrinking "reservoirs" of alpine glaciers that I was referring to.
produce half of the electricity that I consume. A big part of the rest comes from the height difference between Lake Erie and Lake Ontario.
Man-made reservoirs have finite and relatively short life spans. They silt up pretty quickly and a century or so is about the lifespan of a reservoir.
It is the shrinking "reservoirs" of alpine glaciers that I was referring to.
You made a mistake talking about glacial reservoirs, grouping alpine glacier with Continental and lake inversion. If you keep talking I'll keep adding to your mistakes
By the way, you have tickets for the next sailing of the ark tomorrow morning.
By the way, you have tickets for the next sailing of the ark tomorrow morning.
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Reminds me of another poster a while back who instead of admitting to a mistake would just jump to another subject to argue.....
I remember a poster that when he did make a mistake and admitted it the quantity and quality of things learned was 'a leap' forward rather than the 'big fat zero' that happens as soon as the trolls move in. The 'conclusion' was that if the clouds above us were closer to the ground then much of the higher land would be above the clouds and they would be the 'most advanced' on the planet. To spell it out so you get it it means that in an ice-age that lasts 300,000 years starts off with everybody on a different page but after all that time in close proximity they had a common language and that means they could build almost anything. (a lot more advanced than we are). Nothing more magical than co-operating rather than fighting wars)
There also the desert between DaSleeper's ears, a land with no men it if I ever saw one.
There also the desert between DaSleeper's ears, a land with no men it if I ever saw one.
Probably the reason that Mother Nature in her great wisdom and sagacity had ice float to the top!
Probably not at all until the entire lake is at 4C.
You are all near de Nile. The Western cities are going to have water shortage problems. Wait for it.
