Saturday, June 20, 2009

The Great Mystery Of The Great Lakes

There is a real mystery about the Great Lakes of North America and it has nothing to do with what actually happened to the ship, the Edmund Fitzgerald.

These lakes are the largest system of fresh water on earth and the largest of the lakes, Lake Superior, is the largest body of fresh water. The lakes are the focal point of a vast watershed which brings water from rain and melting snow into the lakes. Niagara Falls is essentially the overflow valve of the upper Great Lakes so that water flows over the falls on it's way to the sea.

The mystery of these lakes is why does the water in the lakes flow from deepest to shallowest on it's way to Niagara Falls, rather than the other way around. All across the world, water flows from shallow to deep. Small streams flow into larger streams, which flow into rivers, which may flow into larger bodies of water, which finally flow into the sea.

So why do the Great Lakes have it backward? Lake Superior is the largest and deepest of the lakes but water flows from it into two smaller and shallower lakes, Huron and Michigan. From there, the water flows into the shallowest of them all, Lake Erie. From there, the water flows over the falls to Lake Ontario which, while much deeper than Lake Erie is still more shallow than the others and is the smallest of the lakes in surface area.

According to all of the laws of nature, this just does not make sense. Water flows from the shallow to the deep on it's way to the sea, yet the largest system of fresh water in the world has managed somehow to get it backwards. I am unsure if anyone else has wondered about this but it seems to me to really require some special explanation.

Furthermore, one of the greatest rivers of the world, the Mississippi, has it's beginnings close to Lake Superior. Obviously, the lakes must have an outlet to the sea due to the vast amount of water that comes in from rain and melting snow in it's watershed. So, why didn't the water from the deepest of the lakes find it's way to the greatest river in the country instead of going the utterly illogical route through ever-shallower lakes, over the falls and, through a long and torturous route to the sea?

There was a lot more water around at the end of the last ice age 12,000 years ago than there is now, due to melting glaciers, and a surge of water from Lake Superior could have easily found it's way westward to the beginnings of the Mississippi River in northern Minnesota and the lakes, except Lake Ontario, could have drained to the sea by that route. Then the water of the lakes would flow from shallowest to deepest before heading for the sea and everything would make perfect sense.

But before declaring the Great Lakes as completely illogical, there is another factor to be considered. What about the force that I have pointed out in the posting on this blog "The Equatorial Force" .

In those postings, I described how the rotation of the earth has an effect. For example if all of the rivers on earth are considered, it is easy to see that far more water flows eastward than westward and far more flows toward the equator than away from it. This is caused by the momentum provided by the eastward rotation of the earth.

So, maybe the flow pattern of water in the Great Lakes is not so illogical after all. The rotation of the earth has quite an effect on bodies of water this large. This rotation provided eastward momentum to the water overflowing the Great Lakes Basin at the end of the last ice age. This caused surges of water to "choose" an eastward route, rather than the seemingly more logical route through the deepest of the lakes westward to the Mississippi River.

This eastward momentum proved to be more important than the general principle that water flows from shallow to deep. The lakes are aligned so that the flow is more east-west than north-south so the eastward momentum had more of an effect than did the southward, toward the equator.

So it turns out that instead of being nonsensical, the flow pattern of water in the Great Lakes is actually one of the finest examples that there is of my Equatorial Force caused by the eastward rotation of the earth.

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