Great Lakes of North America. What are the Great Lakes

general information

The Great Lakes formed at the end of the last ice age, approximately 10,000 years ago, when the glacier began to retreat and melting water filled the valley carved by the ice. As the glaciers retreated, their edges left sharp "cuts" that are visible today in Wisconsin and Ontario's Bruce Peninsula, as well as at Niagara Falls.

Five lakes make up more than 20% of the world's fresh water - 22,812 cubic meters. km. All five lakes are among the 18 largest lakes in the world, both in terms of area and volume. Their total area is 151,681 sq. km - this is more than the territory of England, Scotland and Wales combined.

Upper Lake is the largest and deepest, in fact, its area exceeds the area of the Czech Republic. Lake Michigan is the second largest by volume, while the shallower Lake Huron is the second largest. Lake Erie is the smallest and smallest in volume, while Lake Ontario is the smallest in area. It is also located at a much lower altitude than other lakes.

From the lakes flows the St. Lawrence River, flowing into Quebec, past the Gaspé Peninsula, and flowing into the Atlantic Ocean. In those days when the railroads were not yet built, it was the St. Lawrence River that served as the main transport artery between the large industrial cities on the shores of the lake. Today, tourism is an important component of the economies of both countries near the border, as is industrial fishing.

Due to their size, the lakes have an impact on the climate in the region. In summer, their waters absorb heat, keeping them cool, while in winter they protect the area from the cold. However, it is in winter that the lakes look most impressive. Dry continental air masses, usually coming from the west, absorb the moisture of the lakes, and as soon as they reach the cold air over the spaces to the east, heavy snowfalls begin, sometimes snow falls several feet high. They say that at this time it can snow literally from nowhere, from a completely cloudless sky.

There are several national parks on the shores of the Great Lakes. Here you can go sailing, kayaking, fishing or diving, and in the forests surrounding the lakes you can go cycling, birdwatching, hiking and camping. Bald eagles and herons can be found along the lakeshores in deserted areas, while black bears, wolves, elks and even the endangered Canada lynx can be found in more secluded forests.

The basin of the lakes is inhabited by more than 33 million people, more than one tenth of the total population of the United States of America and a quarter of the inhabitants of Canada. The governments of both countries are making great efforts to prevent pollution of the area, trying to protect this magnificent land from the damage caused by civilization.

The Great Lakes of North America is a unique natural system consisting of five large lakes connected to each other by rivers and straits. What lakes are honored to be called great, what is the history of their occurrence, and where they are located, we will find out in this article.

General information

The Great Lakes are located on the territory of two states: Canada and the United States of America. They belong to the Atlantic Ocean basin, and the occupied area is 245.2 thousand square meters. km. with a volume of water 22671 cubic meters. km. This water system includes five major freshwater lakes and numerous very small lakes and rivers.

Rice. 1. Great lakes.

In terms of the size of the occupied area, the Great Lakes surpass even Lake Baikal by about 7.5 times. Despite this, Baikal holds a larger amount of water, which indicates the shallow depth of the Great Lakes. The average depth of Lake Baikal is 744 meters, and the depth of the North American Pearl is 147 meters.

The Great Lakes include:

Lake Superior;
Lake Huron;
Lake Michigan;
Lake Erie;
Lake Ontario.

All lakes are interconnected by rivers, canals and straits and together form a unique water system that exists only in North America.

Origin story

The Great Lakes system originates 12 thousand years ago, when the territory of modern North America was covered with ice. Under the influence of tectonic processes, depressions were formed - pits, which gradually filled with fresh water. Where did the water come from? The fact is that the climate gradually changed and the mainland became warmer. The ice melted, and the resulting water filled the depressions, thereby forming lakes.

Lake Michigan

Lake Michigan is the fourth largest freshwater lake in the world. Its peculiarity lies in the fact that it is located exclusively in the United States. All the other "big five" lakes occupy space in both the US and Canada. Scholars often do not separate Huron and Michigan into separate lakes, but treat them as a single entity. After all, they are on the same level and are connected by a deep strait.

In the language of the Indians who originally lived on these lands, the name mishigami is translated as "big water".

Lake Erie

Most of Lake Erie is located in the United States, in Canada it washes the shores of the province of Ontario. It is connected to Lake Ontario by the Niagara River. It is in the bed of this river that the world-famous Niagara Falls is located. Compared to the rest, the lake is not at all deep, the water in it warms up well, which contributes to the reproduction of many species of fish.

Lake Ontario

The last lake in the Great Lakes is Lake Ontario. It is the smallest in this water system. Its area is 20 thousand sq. km. It is connected to the Atlantic Ocean by the St. Lawrence River. Since the Atlantic Ocean is very close, the water in the lake almost never freezes.

Great Lakes

English Great Lakes, fr. grands lacs

Great Lakes, satellite view (April 24, 2000)









Location

45° N sh. 84°W d. HGIOL

Countries







Audio, photo and video at Wikimedia Commons

Schematic map of the Great Lakes

Water levels in the Great Lakes

The formation of lake basins is most influenced by tectonic processes; The Great Lakes began to form at the end of the last ice age, about 10,000 years ago, when the mass of the glacier pushed through the earth's crust, and after the glacier melted, a slow reverse process began - glacioisostasia, which is also very noticeable in the region of the Gulf of Bothnia and Finland. The water mass of the lakes was formed during the melting of the glacier. The northern coast of the Great Lakes rises faster than the southern coast, which leads to the effect of "transfusion" of water and the slow flooding of land in the south. Previously, the Great Lakes had an additional flow through the current Illinois and Ottawa rivers, but due to all the same geological processes, they, being still near the shores of the lakes, have somewhat changed their course and radically changed their source. As a result, today natural flow exists only along the St. Lawrence River.

Geography

General

The Great Lakes are among the largest accumulations of fresh water on Earth. Only Baikal, the Great African Lakes and the glaciers of Greenland and Antarctica can compete with them. They are interconnected by rivers and canals, and therefore water flows from one to another. Lake Superior is the largest freshwater lake in the world in terms of area, and Ontario alone is larger than Europe's largest Lake Ladoga. Their average depth, not being very great, exceeds the average depth of the Baltic and North Seas.

The length of the coastline (including islands) is about 18 thousand km. The total area is 244,106 km², the basin area is 768 thousand km² (including the area of the lakes themselves), the total volume is 22,671 km³, four lakes have depths exceeding 200 m, and only Lake Erie has a maximum depth of 64 m, while St. Clair has only 8. The largest and deepest of the Great Lakes is Lake Superior, the smallest is Lake St. Clair.

Several hundred small rivers flow into the Great Lakes, the flow from the lakes occurs along the St. Lawrence River, flowing from Lake Ontario and flowing into the Atlantic Ocean; the average water flow at its source is 6637 m³/sec.

Previously, waste from sewage, paper and other factories was dumped into these lakes. At first, Lake Erie turned out to be significantly polluted, it was overgrown with silt, and many species of commercial fish disappeared from it. The government has allocated significant funds to clean up the lakes. Now the lakes are relatively clean. The Great Lakes are very important objects of recreation and navigation.

Lake	St. Clair	Ontario	Erie	Michigan	Huron	upper lake
Surface area	1114 km²	19,000 km²	25,700 km²	58,000 km²	59,600 km²	82,400 km²
Volume	3.4 km³	1640 km³	480 km³	4900 km³	3540 km³	12,000 km³
Height above sea level	175 m	75 m	174 m	176 m	176 m	186 m
Average depth	3.4 m	86 m	19 m	85 m	59 m	147 m
Max Depth	8 m	246 m	64 m	281 m	230 m	406 m
Major settlements	Detroit, Michigan Windsor, Ontario	Hamilton, Ontario Kingston, Ontario Oshawa, Ontario Rochester, New York Toronto, Ontario Mississauga, Ontario	Buffalo, New York Cleveland, Ohio Erie, Pennsylvania Toledo, Ohio	Chicago, Illinois Gary, Indiana Green Bay, Wisconsin Milwaukee, Wisconsin	Sarnia, Ontario Port Huron, Michigan Bay City, Michigan	Duluth, Minnesota Sault Ste. Marie, Ontario Thunder Bay, Ontario Marquette, Michigan

According to geologist John King of the University of Rhode Island, water levels are sensitive to climate change and could change more dramatically in the 21st century.

In January 2013, the level of Lake Michigan and Huron updated a record (since the start of regular observations, 1918) low water level (prior to this, the minimum was recorded in March 1964), about 2 meters below the maximum level (October 1986). There are several reasons for this: dredging, mining, soil erosion.

Islands

Approximately 35,000 islands are scattered across the Great Lakes. The largest among them are Manitoulin in Lake Huron, the largest island in the world, located in a fresh lake (area larger than the area of Luxembourg); inside it has its own lake - Manitou, inside which there are also several islets. Another major island is Air Royal on Lake Superior.

lakes

upper lake

Huron

Michigan

Erie

Ontario

Geology

The underlying tectonic processes that formed the Great Lakes took place between 1.1 and 1.2 billion years ago, when two previously connected tectonic plates separated from each other and created a mid-continental rift.

The Great Lakes are estimated to have been formed at the end of the last ice age (about 10,000 years ago) when the Laurentian Ice Sheet retreated. The retreat of the glacier left behind a large amount of meltwater that filled the pools carved by the glaciers.

When the glacier retreated, Lakes Michigan and Erie were the first to clear the ice. In their place, lakes appeared one after another. Chicago, momi, Whittlesey with a general flow into the Mississippi River basin. When lakes Ontario and Huron cleared of ice, a lake formed in their place. Algonquin with runoff to Lake Erie. During the greatest development, the area of Lake Algonkin reached 250 thousand km². With the retreat of the glacier, Lake Ontario formed as a separate body of water - lake mohawk- with a runoff through the Mohawk River into the Hudson River and further into the Atlantic Ocean. Further retreat of the glacier opened up a runoff through the St. Lawrence River.

Climate

The climate of the Great Lakes is humid, temperate, similar to the climate of the Middle Baltic. The Great Lakes region is characterized by sharp changes in weather conditions. This is due to the proximity of such different areas as the cold Hudson Bay in the north and the very warm Gulf of Mexico in the south. The most changeable season is winter, it is snowy, active cyclones are observed. Cyclones are also associated with frequent intrusions of Arctic air at this time, leading to a sharp cooling, while sometimes important areas for navigation are ice-bound in a matter of hours. In winter, ice first covers Lake Superior, then Huron and Michigan, and lastly Erie. The lakes are not completely covered with ice, but navigation stops, becoming impossible from December to April. Spring lasts a long time, frosts are frequent. Summer is cool, it is, like winter, changeable, with frequent rains and strong winds. Autumn includes a period of up to two weeks called "

On the North American continent there is a beautiful corner of nature known as the Great Lakes. The basin of these reservoirs is considered one of the largest drainage systems on our planet. It occupies a rather impressive territory - 768 thousand km². It contains almost 18% of the world's fresh water! Information about where the Great Lakes are located, their origin and description can be found in this article.

History of occurrence

Scientists believe that about 12 thousand years ago there was an icy desert on the site of North America. The origin of the Great Lakes is associated with the formation of tectonic depressions, which were subsequently plowed and deepened by a giant glacier, slowly moving from north to south. Huge masses of ice crushed the soil, consisting mainly of soft sandstone and shale. They easily crushed mountains and moved huge blocks from their place, as a result of which even deeper depressions and moraines were formed. Thus, wide pits were formed, which, after the melting of glaciers, were gradually filled with water.

General information

This largest drainage system is located in North America, in the St. Lawrence River basin, on the border of two states - the United States and Canada. The Great Lakes are a group of the five largest bodies of water, which includes the Superior, Huron, Michigan, Erie and Ontario. The total length of their coastline is approximately 18 thousand km. They contain more than 22 thousand km³ of water, and their surface area is 245.3 thousand km². Lake Michigan is located in the United States. As for the rest of the reservoirs and the rivers connecting them, the border with Canada passes through them.

The Great Lakes system itself is special, as it is arranged in steps. The difference in the height of the placement of the Upper, Huron, Michigan and Erie is no more than 9 m. But as for the lake. Ontario, it is almost 100 m lower than the rest. All of the above reservoirs are interconnected by small, but rather full-flowing rivers. Thus, Upper and Huron are connected via the St. Marys River, 112 km long, and Ontario and Erie - through Niagara, which forms the world-famous waterfall of the same name, whose height is about 50 m. In addition, Huron is connected to Erie by the 43-kilometer St. Clair, and with Lake Michigan - the Strait of Mackinac, the width of which is at least 3 km.

Proximity of settlements

The Great Lakes (this is clearly visible on the map) are replenished by several hundred small streams, and the flow is carried out along the St. Lawrence River, which flows from Ontario directly into the Atlantic Ocean. These waters have very low mineralization - only up to 0.13 g/l. About 170 different species of fish are found in the system of these lakes, including salmon, perch, trout, carp, whitefish and many others.

It must be said that the Great Lakes region in the southern and southeastern parts is adjacent to the very densely populated and industrialized, and from the west and north - to the agrarian and raw materials territories of Canada and the United States. So, in the USA, on the banks of Michigan, there are two largest cities - Milwaukee and Chicago, near Erie - Cleveland and Buffalo, and near Ontario - Canadian Toronto. In addition, the lakes communicate with the Mississippi basin with the help of a whole system of navigable canals.

Upper

Lake Superior is the largest fresh water body in North America. In terms of the amount of fresh water, this giant ranks third after Russian Baikal and African Tanganyika. The average depth of the largest American lake is 147, and the maximum is 406 meters. It contains over 11 thousand km³ of water.

The northern shore of Lake Superior is located in the province of Ontario (Canada). The rest of the coast is located in the United States. The lands of Minnesota extend from its western part, Michigan from the south, and Wisconsin from the southwest. The total length of the coastline is 4387 km. The width of this freshwater giant reaches 260, and the length is 560 km. This reservoir is located at an altitude of 182 m above sea level.

It is worth noting that the coastline of Lake Superior is quite heavily indented by numerous bays and bays. The south coast has a flat landscape and sandy beaches. This picturesque place was chosen by the inhabitants of the North American continent, who tend to come here with their families on vacation. As for the northern coast, it consists entirely of rocks and cliffs.

All the Great American Lakes are fed by a large number of medium and small rivers. For example, approximately two hundred flows into the Upper, and the largest is the river. Nipigon. In addition, the lake has its own islands. The largest of them is Isle Royal, which is 72 km long and 14 km wide. Now on the territory of this island there is a national park connected to the mainland by ferries constantly running back and forth.

Huron

For some time now, some geographers have been trying to combine this lake with the third largest body of water - Michigan. Such attempts are explained by the fact that they are on the same level. These rather impressive water masses are very similar to two communicating vessels with similar characteristics. The Huron is the second largest body of water in the Great Lakes. It occupies an area of almost 6 thousand km². With regards to the volume of fresh water, it is inferior to Lake Michigan and amounts to 3.538 thousand km³. Huron is located 177 m above sea level.

The average depth of the lake does not exceed 60, and the maximum reaches 230 m. Its coastline is 6.157 thousand km, while the length is 332, and the width is 295 km. In the northern part of Huron is a large island called Manitoulin. It is considered the largest of all that are located in fresh water. Its area is 2.766 thousand km². In addition, people live on it. The population of this island is approximately 13 thousand people.

The Great Lakes of North America have always been famous for their large number of rare fish species. Over time, they began to breed in other fresh water bodies around the world. Take at least lake trout. She lives at a depth of 20 to 60 m. Unfortunately, in the mid-1950s, this species of fish was almost completely destroyed. And the point is not only in its excessive catch, but also in the appearance of the sea lamprey in the waters of Huron, which came here as a result of the opening of a new channel in 1925.

This lake is extremely famous, first of all, for the fact that frequent storms and storms arose on it, after which numerous ship cemeteries were formed. Judge for yourself, since the beginning of the 18th century, its waters have swallowed up more than one thousand ships! According to the documents, the first ship to sink was the Griffin. His downfall took place in September 1679. He was walking with a large load of furs. But the most widely known event is the Great Storm that hit the Great Lakes in 1913. It was a real hurricane, rampaging in the area for four days. Huron suffered the most from this element. In its waters, the elements found 36 ships, most of them washed ashore, but 10 ships sank along with their crews. The victims of the Great Storm were 235 sailors.

On Lake Huron there is a small bay of Saginay, located in the southwestern part of the reservoir. Here at the bottom rests 185 sunken ships. Another large ship graveyard is located near Manitoulin Island. 212 ships are buried there. Almost all of them were trucks carrying furs, grain or other goods, so the damage from their crashes amounted to more than one million dollars.

Michigan

This lake is the third largest freshwater body of water and, unlike its counterparts, located entirely within the United States. As mentioned above, all the Great Lakes of North America are located in steps. This reservoir is, like the Huron, 177 m above sea level. Its average depth is 85, and the maximum is 281 m. Lake Michigan occupies about 58 thousand km². Its coastline is 2636 km long, 190 km wide and 494 km long. Beaver is the largest island in Lake Michigan. Its length is 21, and its width is 10 km. It is part of the archipelago of the same name with many smaller islands.

Four states adjoin this reservoir: Illinois, Michigan, Wisconsin and Indiana. About 12 million people live along the entire coastline. The largest coastal cities are Milwaukee and Chicago. Lake Michigan in the summer is very popular with vacationers. It is famous for its beaches with clean, soft and slightly creaking sand underfoot. It owes this feature to the high content of quartz. In addition, the formation of sand dunes has been observed along the Michigan coast. As for the local water temperature, it remains warm even at the end of summer.

From the north, lake shores are often covered with whole colonies of stones of coral origin. Often their surface is covered with rather original and peculiar patterns, which distinguishes these natural formations from the well-known ordinary pebbles. Almost the entire east coast of Lake Michigan is covered with rocks, while the south coast is covered with dunes. This feature can be explained by the predominance of westerly winds in these places. It is they who in winter contribute to the formation of a rather impressive layer of ice on the surface of the lake.

Erie

This is the fourth largest body of water, one of the five Great Lakes. It covers an area of 25.7 thousand km². Erie stretches for 388 km, and its width is a little over 90 km. This is the shallowest reservoir, the average depth of which is only 64 m. This lake is located on the territory of three US states - Ohio, New York and Pennsylvania, as well as in the province of Ontario (Canada). Numerous islands are located in its southwestern part. There are several large cities along the coast of Erie, such as Buffalo, Cleveland, Toledo and others.

As you know, the Great American Lakes together and separately are unique corners of nature. Eri was no exception. The climate here is really unusual. This is the so-called snow effect. It occurs due to the circulation of cold air masses in the winter months over warm lake water. Reaching Buffalo, he literally brings down a huge amount of snow on the city. The snow effect is a short-lived phenomenon that disappears when Erie freezes.

Ontario

Its area is 19.5 thousand km². It is the smallest of the Great Lakes. Its average depth is 86, and the maximum is 244 m. Despite its relatively small size, Ontario is the most important transport artery for both Canada and the United States. Due to its great depth, this lake never completely freezes over, so ships ply here all year round.

Since Ontario is located below all the Great Lakes, that is, only 75 m above sea level, a large number of locks have been equipped for convenient navigation, which have a limited width. This could lead to a significant reduction in the volume of freight traffic. To prevent this from happening, they developed the so-called lake trucks, which are the largest river vessels in the world, reaching a length of up to three hundred meters.

Ontario, like all of the above Great Lakes, has a special climate. The local conditions contribute to the successful development of agriculture, as the spring flowering of plants is delayed here, and ripened fruits, such as peaches, plums, apples and cherries, are stored until late autumn. Even on this coast, grapes grow well, from which they make a delicious and fragrant drink.

abuse

The large-scale and reckless use of these unique reservoirs in the United States and Canada could not but lead to quite serious socio-economic and environmental problems, and above all, to pollution of not only surface, but also groundwater.

Especially detrimental to the Great Lakes was the intensively developing economy of the United States after the Second World War. It was during this period that the unprecedented growth of American industry began. Industrial, domestic and other effluents poured into these water bodies without any treatment. The result of such actions was a sharp decrease in the oxygen content, and as a result, the mass death of fish.

By that time, the use and further disposal of toxic chlorine compounds and synthetic fertilizers had led to their entry into food products. By the end of the 60s of the last century, about 40% of all water systems in the United States became unsuitable for both fishing and bathing due to extreme pollution. Moreover, quite large volumes of toxic liquids fell into the Great Lakes. The United States has thus become the main cause of the ecological catastrophe in the area.

By the way, already in the 70s of the last century, Lake Erie turned out to be practically “dead” due to intensive discharges of the chemical industry. All this happened through the fault of enterprises that did not pay due attention to high-quality wastewater treatment. As a result, the waters of Lake Erie were oversaturated with phosphorus, causing excessive algal blooms and, as a result, a significant reduction in the fish population.

Ecological situation

Once on the shores of the largest freshwater lakes of the North American continent, many different animals lived, and their waters literally teemed with a variety of fish species. James Fenimore Cooper wrote about all this in great detail and fascinatingly in the not so distant past in his works Deerslayer and Pathfinder, or On the Shores of Ontario. Since then, herds of noble wild deer, thickets of dense deciduous forests have disappeared, and with them the Indian tribes. The American lakes themselves have become an ecologically unfavorable zone.

Despite the fact that the governments of the United States and Canada are making great efforts to protect the natural resources of the Great Lakes, yet this does not bring any significant changes for the better. As long as various enterprises of the metallurgical, chemical and oil refining industries exist near this water system, they will inevitably destroy the ecosystem of these unique reservoirs.

The Great Lakes are unique. They are located on the territory of two countries (USA and Canada) and are connected by a network of rivers and canals, forming a water system. These freshwater lakes are called "great" for a reason, there are 5 of them, the volume of drinking water in them is 22,671 km3, and the total area is 244,106 km2. Without this huge basin, a significant part of North America would be left without water.

There are upper lakes: Superior, Michigan and Huron, and lower lakes: Erie and Ontario.

general information

The depth of the Upper is more than 400 meters. Michigan and Huron provide water to major US cities such as Chicago and Detroit, and between Erie and Ontario is the magnificent Niagara Falls. According to one version, these unique waters were formed after the melting of glaciers. From the chemical composition of the fossils, scientists have determined that once the water in the lakes was much colder. It took more than a hundred thousand years for the icy stream to carve out the five largest pools on earth.

Lake Superior

The most majestic of all five -. During a storm, the height of its waves reaches 12 meters. In terms of volume, the lake is second only to Baikal (the deepest and cleanest lake in the world). Along the coast there are many places for recreation and camping, which tourists enjoy visiting in the summer. Scientific research is carried out here all year round.

Lake Michigan

Lake Michigan, which in the language of the Indians means "big water", has a length of 2.5 thousand km and resembles the Pacific coast. It surprises even the most capricious tourists. Rest near this reservoir is an elite and expensive pleasure, and fishing is considered the most popular activity among locals and visitors here.

Lake Huron

The name Huron comes from the Indian tribe of the Hurons, who previously lived off its coast. The reservoir contains a huge number of islands (about 30 thousand), many of which are natural and historical reserves. Huron water is clean and transparent, but it heats up only by +14 - +16 degrees.

Lake Erie

Lake Erie is the least watery among the Great. Its waters and favorable environment have a great influence on the origin of many different fish, which makes the reservoir very popular for fishing. The best grapes are grown on the banks of the Erie. Agriculture and shipping are developing well here.

Lake Ontario

Lake Ontario resembles a blue endless sea, and the city of Toronto located near it is a major entertainment center for family summer holidays. The major port cities of Hamilton, Rochester and Kingston are located on the low-lying shores of the reservoir. Due to its shallow depth, it never freezes or storms, which contributes to the ideal development of agriculture.

Conclusion

Researchers believe that lakes contain about 18% of the world's fresh water. More than 174 species of fish (families of perch, salmon, cyprinids, etc.) are found in the Great Lakes basin. The best perch fishing in the world, according to scientists, takes place in these places.

Groundwater is the main source of nutrition for the vast basin. And the famous reservoirs themselves supply water to more than 30 million people living in Canada and the United States. The main areas of activity of the population: industry, trade, tourism, communication. Due to the high concentration of pollution, the decrease in the number of fish and the presence of hazardous chemicals in water bodies, in 1972 an agreement was signed between the United States and Canada to improve the quality of water in the Great Lakes basin, for which the countries allocated several million dollars.

People from all over the world seek to visit this unique natural monument. Tourists call these places "resort paradise". They come there in search of unforgettable experiences, fresh healthy water and clean air will be enough for everyone.