Lakes Superior and Huron became independent, the higher waters of Lake Superior being held back by the rim of the old Cambrian sandstone ledge at that point. Most of the basin is defined by hydrology; watersheds that drain into the Great Lakes and their connecting channels are in the Great Lakes basin. The National Museum of the Great Lakes reveals the varied and fascinating history of our treasured Great Lakes, which make up 84% of all of the fresh water in North America. Many hundreds of millions of years before, events took place which set the stage for the great drama, the like of which has occurred nowhere else in the world. Some of these prehistoric lakes include Lake Algonquin, Lake Nippising and Lake Chippewa. The dramatic part of our story began about a million years ago geologically, a rather recent period. The Great Lakes today hold an estimated 6 quadrillion gallons of water a fifth, or 20%, of all the drinkable water on the surface of Earth. A faster tax write-off would help and this is fully justified. This massively heavy continental glacier had flowed southward, depressing and carving the Earth as it passed over, pushing ahead of it huge piles of eroded rock and gravel called glacial moraines. The result looked like a stack of nested bowls, with the oldest and weakest sedimentary rocks on the bottom and far edges of the basin. This process is known as isostatic rebound. These sediments were easy for streams to erode; the erosion produced a large valley that glacial lobes accessed a billion years later, gouging an even deeper trough that filled to become todays Lake Superior. The glacier then passed over and completely filled this gorge with rock debris, which then became compressed and cemented together, but not as hard as the surrounding rock. Geologists have determined that the shoreline steadily rose as it moved north. One-fifth of that is in the Great Lakes, representing 85% of the liquid surface freshwater in North America. As time went on, these lobes became more like individual glaciers and occupied the basins of the Great Lakes. Unlike the long dead and buried Midcontinent Rift System, the Saint Lawrence Rift System is still seismically active, capable of generating earthquakes over magnitude 5. Mary Caperton Morton (@theblondecoyote), Science Writer. HOT ARTICLEJGR BiogeosciencesUnraveling Forest Complexity: Resource Use Efficiency, Disturbance, and the Structure-Function RelationshipBy Bailey A. Murphy et al. But the 6 quadrillion gallons (~23 quadrillion liters) sloshing in Superior, Michigan, Huron, Ontario, and Erie represent one fifth of the planets fresh water. Let us move now to more recent times. As the Laurentide Ice Sheet began its retreat about 20,000 years ago, glacial floods cut deeply into the exposed geology, and terminal moraines dammed the meltwater to form lakes. (https://www.usgs.gov/special-topic/water-science-school/science/where-earths-water?qt-science_center_objects=0#qt-science_center_objects). The leading-edge glacial lobes followed the easiest paths, which traced along preexisting drainages that had formed in weaker rocks exposed at the surface. Are We Seeing a New Ocean Starting to Form in Africa? Finally, when the glacier had receded beyond the lakes region and the Great Lakes were drawn down almost to their present levels, the three Upper Lakes drained principally from Georgian Bay to Lake Nipissing, down the Ottawa to the St. Lawrence. A lock (LockA locked padlock) or https:// means youve safely connected to the .gov website. We need to be prepared for how those migrations will change our communities and water usage in the coming decades.. Next time I visit, Ill avoid peak mosquito season. The Wabash, of course, was much larger than it is today and later, when the Maumee River itself became established, it flowed in the opposite direction. The ice sheet started forming about 2.6 million years ago, after which it retreated and advanced multiple times in various waves. The geology surrounding Lake Superior is Precambrian in age, with rocks as old as 3.6 billion years exposed in cratonsold, stable blocks of the Earths cruston the Upper Peninsula of Michigan. Lake Ontario came into being, and the Niagara River became Lake Eries outlet. The shape of Lake Superior follows the track of the 1.1-billion-year-old Midcontinental Rift System, which began to break apart the North American craton right through the middle but failed. Retention time for a drop of water in Lake Superior is nearly 200 years. Lake Ontario is the smallest of the five lakes. Then came the epoch known as the Pleistocene, the age of great glaciers, and our story begins. As these glacial lobes retreated northward, tremendous quantities of run-off water drained into the Mississippi valley. The present day Great Lakes have six quadrillion gallons of water, with only the polar ice caps and Lake Baikal containing more. It will be at least 1,000 feet long and 100 feet wide. Man can be proud of his creative genius in learning how to use these raw materials, but after all, how puny are the working of man, as compared to the workings of God! 20,000 years ago, the ice sheet finally began to melt. Our maximum size ships today can carry 25,000 tons and their operating season is restricted to about seven months. Lake Maumee grew to a much greater size, while similar lakes formed at the ends of other glacier lobes, Green Bay, Saginaw Bay and Lake Michigan, all draining down the Mississippi. This Silurian limestone is also called Niagaran, which is exposed in the vicinity of the Niagara River. There are tons of options, from, Read More 11 Amazing Michigan Cider Mills & Apple Orchards in East MichiganContinue, Uncover History at Sanilac Petroglyphs Historic State Park, 5 Fun (& Cheap) Things to Do in Marquette Michigan, Tour Mari Vineyards on the Old Mission Peninsula, Feast with Friends at San Chez Grand Rapids, 11 Amazing Michigan Cider Mills & Apple Orchards in East Michigan, Great Lakes Origin by Diastrophic Processes, THE Best Things to Do in the Upper Peninsula in 2022, Since 1911, Sister Lakes Michigan Has Been a Favorite Vacation Destination, Have a Ball at a Great Lakes Loons Baseball Game in Midland, See the Bright Walls Murals in Downtown Jackson, 18 Best Waterfalls in Michigan to Explore This Year. The rift filled with more than 5 mi (8 km) of sediments as a large basin subsided along the rift zone. Funding provided by the National Sea Grant College Program, National Oceanic & Atmospheric Administration and the State of Wisconsin. About 50 million U.S. and Canadian citizens live and work in the Great Lakes region today, and around half of them depend directly on the lakes for drinking water. A billion years is a very long time, even by geologic standards, said Seth Stein, a geophysicist at Northwestern University in Evanston, Ill. Starting in Lake Superior, the water flows out the lakes southeastern tip down theSt. Marys Riverinto Lakes Michigan and Huron, which actually are two halves of one lake. A gradual climatic change of longer winters, in which the snows of one year overlapped those of the next, caused the formation of two glaciers, one to the west and one to the east of Hudson Bay, known as the Keewatin and the Labrador glaciers. The Great Lakes are an iconic freshwater system that makes up more than 20 percent of the worlds available surface freshwater. Niagara Falls was born about 20,000 years ago and the Lakes, as we know them today, are roughly only 3,000 years old. Eons of erosion have hidden this scar, which runs from Lake Superior in two forks down to Alabama and Oklahoma. One theory explains that the present day lakes are the result of glaciers advancing and retreating over thousands of years. The Great Lakes have been a nexus of migration, transportation, fishing, and trade for thousands of years, with a series of lakes, rivers, and waterways connecting the upper Midwest to the Atlantic Ocean. Any reuse without express permission from the copyright owner is prohibited. Some of the worlds largest grain shipping ports are located on the Great Lakes, and oceangoing ships as well as 1,000-foot lake vessels ply their waters. From west to east, the lakes are named Superior, Michigan, Huron, Erie, and Ontario. Such vessels could each carry up to two million tons in a year. Official websites use .gov Secure .gov websites use HTTPS These formations, known as moraines, make up the boundaries of the present day Great Lakes. Credit: U.S. Army Corps of Engineers, Detroit District, The Midcontinent Rift System (darker) is a failed rift that occurs under Lake Superior. In addition to the Great Lakes themselves, nature, a billion years before, created the iron ores of the Lake Superior region. Isostatic rebound raised the North Bay to levels of two previously existing lakes. Today that figure has shrunk to 200 and many of those will probably see little service in the future. because the oceans contain over 96 percent of water on the planet as saltwater. It was mid-June, and the bloodsuckers were so relentlessbiting through bug spray, layers of clothes, a smoky fire, and a tentthat we cut our 4-day loop in half. The Great Lakes are still here, as beautiful as ever, all 95,000 square miles of them, and in recent years we have conquered the St. Lawrence River and we have the long-sought access to the sea. When Pleistocene glaciation began, glaciers preferentially scoured softer, early Paleozoic sedimentary rocks, avoiding the stronger, younger sedimentary rocks that still protectively cover the lower part of the state today. Smaller lakes with shorter residence times can respond more quickly to changes than bigger lakes, said Dale Robertson, a research hydrologist at the U.S. Geological Survey in Middleton, Wis. That means theres hope for Lake Erie, where toxic algal blooms feeding off nutrients delivered by the Maumee River create water quality issues each summer. We know that it can be done; it is just a matter of doing. Foreign competition is making a strong bid for a share in the supply of this raw material. Currently, around 35 million people rely on the Great Lakes for drinking water, and an additional 56 billion gallons are extracted each day for municipal, agricultural, and industrial use. Lake Michigan continued to drain out the Illinois River where Chicago now stands until about only 3,000 years ago, when the Great Lakes finally assumed their present shapes. From the westernmost tip of Lake Superior at Duluth, Minn., to the easternmost tip of Lake Ontario at Watertown, N.Y., lakes stretch a thousand miles across the heartland of both the U.S. and Canada, creating nearly 9,500 miles of ocean-like shores. Lake Algonquin covered an area of approximately 100,000 square miles with maximum depths of 1,500 feet. Hennepin was one of LaSalles aides. Lake Superior has the deepest point, at a depth of 1,333 feet. Lakes Erie and Ontario are the shallowest and smallest, both carved into weaker shales and connected by Niagara Falls, which flows over a harder dolomite shelf. Retiring earlier this year as Vice-President, Sales, of The American Ship Building Company, at Cleveland, he is now Consultant for the Company. Shared with Canada and spanning more than 750 miles (1,200 kilometers) from west to east, these vast inland freshwater seas provide water for consumption, transportation, power, recreation and a host of other uses. If all the water in the Great Lakes were spread evenly over the continental U.S., the 48 states would be flooded under more than nine feet of water. A lake that is created by a glacier is referred to as a glacial lake. About 7,000 years ago, as the last ice left, the land to the southwest of Lakes Erie and Michigan had risen high enough that the lakes no longer drained in that direction. But in time, the lobes reached the drainage divide where the land sloped toward the ice front. I believe there will be a group of maximum size ore carriers capable of carrying 35 to 40,000 gross tons of ore and I believe that such ships, and others for that matter, will be operated for fully nine months in an average season. Then came Silurian time, when climates were mild and marine life was abundant. JavaScript appears to be disabled on this computer. Leaving Lake Erie, it flows north via theNiagara Riverand overNiagara Fallsinto Lake Ontario. Lake Huron continued to drain eastward out the Ottawa-St. Lawrence rivers until about 5,000-6,000 years ago. Its water plunges over world-famous Niagara Falls into the deeper Lake Ontario, where water stays for about 6 years. The lakes water is usually cold to begin with, because the Great Lakes lie across the 45th Parallel halfway to the North Pole from the Equator and just 1,200 miles from the Arctic Circle, less than the distance between New York City and Miami. The regions other major industries include automobile manufacturing, heavy machinery, paper mills, metalworking and shipbuilding. The original North American continent was a mass of igneous rock which lay to the north of the Great Lakes region. Gradually, through many centuries, the Labrador Glacier withdrew, leaving the end of Lake Superior, which drained down the St. Croix River to the Mississippi. Lakes Michigan and Huron were likewise carved out of softer sedimentary rock that surrounds the harder rock that makes up the state of Michigan. Weve curated the Ultimate Michigan Gifts Guide and are fine-tuning it weekly! As a result, the old outlets into Lake Erie and the Illinois River were reestablished, but Georgian Bay had an outlet into Lake Ontario and from that Lake into the Mohawk. There is now a gorge that was carved by the Lake Chippewa outflow that lies submerged below the straits of Mackinac. 97.5% of Earths water is salty, either in the oceans or as salty groundwater. They are a dominant part of the physical and cultural heritage of North America. Above the Cambrian came the Ordovician, which was mud deposited from an ancient sea, and becoming a soft shale. The Saint Lawrence River, along with the basins that hold Lakes Erie and Ontario, sits inside the Saint Lawrence Rift, a 1,000-kilometer-long scar that dates back to the opening of the Iapetus Ocean between the paleocontinents of Laurentia, Baltica, and Avalonia. There were several stages of the Erie basin and their beaches can be seen today in the vicinity of Cleveland. Meanwhile, the Iroquois Indians, along the southern shores of Lake Erie, prevented travel from that direction and Lake Erie was yet to be discovered and seen by the white man. This last glacier came in lobes, which left ridges roughly following the contours of the Lakes themselves. They have coastal currents including dangerous rip currents and occasional large tide-like changes in coastal water levels calledseiches(pronounced say-shez) caused by prolonged strong winds and passing storms, as well as storm surges and edge waves. In Michigan, standing anywhere in the state, you are within 85 miles of one of the Great Lakes. Michiganwith the exception of half of the Upper Peninsulalies within the Michigan Basin, a circular basin that extends from far eastern Wisconsin to the eastern edge of Lake Huron, and from halfway through the Upper Peninsula south to northern Indiana and Ohio. At such places, large crescent-shaped lakes would form. But the areas the glacier eroded, and therefore the shape of the lakes, were determined by geology long before that. The Wisconsin glaciation occurred about 200,000 years ago and, in its final retreat, some 35,000 years ago, the Great Lakes began to be established. Ten years ago there were 300 in the ore trade alone. We also have 3,288 miles of Great Lakes coastline, the most freshwater shoreline in the world. This paper was presented at the Annual Meeting of the Great Lakes Historical Society, June 13, 1962. Together, the U.S. and Canada share responsibility for protecting and caring for one of the most valuable natural treasures in the world five magnificent gifts of the glaciers. Even mountain ranges were formed, worn down and then thrown up again, over the eons of time. Both originally drained to the southwest, out the Maumee-Wabash-Ohio and Des Plaines-Illinois rivers, respectively, to the Mississippi River. How can we cope with such formidable competition? As the glaciers scoured out the soft rock, they left behind chasms, which filled with water and became Lakes Michigan and Huron. To turn the trick, however, we must have larger ships and a longer operating season. The story of the Great Lakes began over 1 billion years ago, when the ancient supercontinent Laurentia began splitting in half. Ontario, the only Canadian province bordering the lakes, contains a third of Canadas population, while nearly 15 percent of the U.S. population lives in the region. Synopsis: The Great Lakes contain 20% of Earths liquid surface freshwaterenough water to cover the contiguous United States in about 10 ft (3 m) of water. Evidence of the rift is visible at Lake Superior, which is ringed by cliffs of billion-year-old basalt that erupted into the active rift, giving the largest lake a uniquely rugged shoreline. Share sensitive information only on official, secure websites. The Great Lakes are truly one of Americas great places, in natural beauty and history. New building berths are necessary, new dry docks, new loading facilities and new unloading terminals. Thus was born the first of the Great Lakes, the ancestor of Lake Erie. The Great Lakes area was a sort of submerged basin or bowl which gradually became lined with layers of materials, some hard and some soft, but finally, when the whole region was above sea level, a great river system existed.
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