The Great Lakes

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Podcast Transcript

Located in the middle of North America lies one of the largest collections of freshwater lakes in the world. 

These lakes have a unique geological origin, and function like few lakes on Earth. 

Also, given their location, they are home to several large industrial centers and is part of one of the most important economic waterways on the planet. 

Learn more about the Great Lakes, how they were made, and their importance on this episode of Everything Everywhere Daily.


The Great Lakes are a system of five enormous lakes that lie between the United States and Canada. 

Collectively, the five lakes are the largest in the world in terms of area and the second largest in terms of volume, just slightly behind Lake Baikal, which will be the subject of a future episode. 

For those of you who are wondering why the Caspian Sea isn’t listed, it is because the Caspian Sea isn’t generally considered to be a lake. The reason is that the Caspian Sea isn’t a body of freshwater. Its water is salty, although only ? the salinity of the oceans. 


It is an inland body of water, but it is different enough that it doesn’t fit the general classification for lakes. 

The five Great Lakes are Superior, Michigan, Huron, Erie, and Ontario.

While each of the five lakes is separate, they are all interconnected, creating a single waterway. 

The surface area of the Great Lakes is approximately the size of the United Kingdom. By surface area, Lake Superior is the largest lake in the world, with Michigan coming in third, Huron fourth, Erie 10th, and Ontario 12th.  

Other lakes on the list are three of the African Rift Lakes, Lake Baikal, and Great Bear Lake in Canada. 

The Great Lakes were created around 14,000 years ago during the last ice age. The massive ice sheets which covered North America created large depressions in the locations of the Great Lakes. When the glacier retreated, the depressions filled up with water creating the lakes we know today.

One of the lakes which is always compared to the Great Lakes is Lake Baikal in Russia, which is the largest lake in the world in terms of volume of water, by a wide margin. Baikal, which will also be the subject of a future episode, is the result of a continental rift, similar to what created the great rift lakes in Africa. 

Any discussion of individual lakes has to start with the biggest of the lakes, Lake Superior. 


As I previously mentioned, Superior is the largest lake in the world by area and the third largest by volume behind Baikal and Tanganyika. A full 10% of all the fresh water in the world can be found in Lake Superior. 

The Ojibwe people who lived on the northern shore of the lake called it “gichi-gami,” which subsequently became Anglicized by Henry Wadsworth Longfellow into “Gitche Gumee” and was subsequently popularized by Canadian singer Gordan Lightfoot in his song The Wreck of the Edmund Fitzgerald.

Superior is the deepest of the Great Lakes by far, with an average depth of 483 feet or 147 meters and a maximum depth of 1,332 feet or 406 meters. 

Because of its depth, Superior holds more water than all four of the other Great Lakes combined. There is enough water in Lake Superior to cover the entirety of North and South America to a depth of 30 centimeters or 12 inches.

There is one notable island in Lake Superior, Isle Royle, in the state of Michigan. If you look at a map, it might seem odd that Isle Royale is part of Michigan, given it is right off the shore of Minnesota. The island was ceded to the United States by Britain in the 1783 Treaty of Paris, and then given to Michigan when it became a state 20 years before Minnesota. 

Superior is the closest thing you will ever experience to visiting the ocean without actually visiting the ocean. 

Outside of some areas immediately near the shore, the lake does not freeze over in the winter. By the same token, it also doesn’t warm up much in the summer, meaning only the most intrepid swimmers would actually try to go swimming in Lake Superior. 

The next largest of the lakes is Lake Michigan. 

Lake Michigan is the second largest Great Lake in terms of water volume, the third largest in terms of area, and the only one of the lakes which lies solely within the United States. 

Hydrologically speaking, Lake Michigan and Lake Huron are actually the same lake. The two lakes are connected via the Straits of Mackinac, which at its narrowest is only 3 ½ miles or 5.6 kilometers across. It is short enough that it is spanned by the Mackinac Bridge.

The water levels in both lakes are the same, and water can flow back and forth between them depending on conditions. 

The largest city on Lake Michigan is Chicago. The city’s location was determined by the creation of the Illinois and Michigan Canal that connected Lake Michigan and the Mississippi River Basin. It is a very short canal, but it allowed for a ship to theoretically travel from New Orleans to Montreal without ever having to enter the Atlantic Ocean. 

For people in Wisconsin or Michigan who want to visit each other, it can take a very long time to drive around the lake. During the summer, there is a ferry service that can turn an almost 500-mile car ride into a 60-mile ferry ride. 

Lake Huron is connected to Lake Superior via the Saint Mary’s River and the Soo Locks, which are located between Sault Ste. Marie Michigan and Sault Ste. Marie, Ontario.

Within Lake Huron sits the large Georgian Bay, which lies entirely within the Province of Ontario. In Georgian Bay lies Manitoulin Island, which is the largest freshwater island in the world. 

Manitoulin Island is large enough to have lakes of its own. One of those lakes, Lake Mindemoya, has an island called Treasure Island. 

Treasure Island is the world’s largest island on a lake on an island on a lake. There is actually a settlement on the island, meaning someday someone could build an artificial lake on it with an island in the middle, making an island on a lake on an island on a lake on an island on a lake. 

When that happens, we will have achieved island-lake inception.

Lake Huron flows south through the St. Clair River, into a widening of the river known as Lake St. Clair, and then to the Detroit River. 

Across the Detroit River are the cities of Detroit, Michigan, and Windsor, Ontario. This is the busiest border crossing between the US and Canada. Because the river winds, it also results in a trivia question: what country lies directly south of Detroit? Answer, Canada. 

The Detroit River then empties into Lake Erie.

Lake Erie is the fourth largest lake but substantially smaller than the other three lakes I’ve mentioned so far. It has only 44% of the surface area of Lake Michigan. It is the smallest of the lakes by volume.

The lake is the location of Point Peele, which is the southernmost point of the Canadian mainland, and also Middle Island, which is just off Point Peele and is the southernmost piece of Canadian land.

Erie is the shallowest of the Great Lakes, which means it has the lowest retention time of the lakes as well. Retention time is just the median amount of time water says in a lake. The retention time for Lake Erie is 2.6 years, whereas for Lake Superior is 191 years. 

Lake Erie has several major ports, including Toledo and Cleveland, Ohio, Erie, Pennsylvania, and Buffalo, New York. Buffalo lies at the extreme eastern side of the lake, which results in it getting extreme amounts of snow. 

The snow is the result of what is known as the lake effect. It is the result of cold, dry air that blows over warmer lake water. As the prevailing winds on all the Great Lakes blow west to east, that means locations on the eastern side of the lakes can get a lot of snow.  

I live on the western side of Lake Michigan, and while it can get cold, we don’t get nearly as much snow as places north of here in the Upper Peninsula of Michigan, which are on the eastern shore of Lake Superior. 

Superior, Michigan, Huron, and Erie all roughly are at the same elevation. Other than the Soo Locks, which drop 21 feet or 6.4 meters, you can travel by water without much difficulty. 

However, this all changes once the water leaves Lake Erie. Lake Erie is at an elevation of 173 meters or 569 feet above sea level. However, by the time water flows into Lake Ontario, it has dropped 326 feet or 100 meters. 

Most of this drop occurs in a single spot which you are probably familiar with, Niagara Falls. The Niagara River is extremely rough, which is why it was the location for some of the earliest large hydroelectric plants in North America. 

Ships going from Lake Erie to Lake Ontario will travel by the Welland Canal, which cuts through Ontario. There are a series of eight locks that raise ships up and down to cover the change in elevation.

Lake Ontario has a rather light population on the American side, but on the Canadian side is the largest city on the shore of any of the Great Lakes, Toronto. 

When water leaves Lake Ontario, it is done with the Great Lakes, but its voyage is still not complete. 

The last body of water it has to traverse is the Saint Lawrence River. The Saint Lawrence River sits on the border of Ontario and New York before flowing into Quebec. 

The river drops the final 75 meters or 246 feet from Lake Ontario. Passage through the Saint Lawrence was possible but not easy for bigger ships.

This led to the construction in the 1950s of the Saint Lawrence Seaway, which is a collection of locks and canals alongside the river. 

The entirety of all the lakes, rivers, locks, and canals which connect the Great Lakes together are collectively known as the Great Lakes Waterway. This system allows ships to travel from the Atlantic Ocean to the Great Lakes’ most distant port, Duluth, Minnesota, for a total of 2,340 miles or 3,770 kilometers.

There are over 100 freighters that operate just on the Great Lakes. Most of these ships only operate on the lakes as they are too large to use the Saint Lawrence Seaway. 

Over 162 million tons of dry bulk goods are transported on the Great Lakes every year, with the biggest products being iron ore, grain, and potash. The iron comes from northern Minnesota, the grain from all over the upper great plains, and the potash comes from Canada. 

Few people purposely visit the Great Lakes like they would a beach on the ocean. The beaches aren’t as good, and the water is much colder. However, because the Great Lakes are much smaller than any ocean, you can experience them by driving around them. A trip around Lake Superior is one of the best things you can do in North America, yet few people bother to do it.

Economically, the Great Lakes are one of the world’s most important inland waterways. Hydrologically they are one of the world’s most important reservoirs of fresh water. Politically, the serve as the most important boundary and area of cooperation between the United States and Canada.

For these reasons and for their raw size, Great Lakes collectively are perhaps the most important lakes on Earth. 


The Executive Producer of Everything Everywhere Daily is Charles Daniel.

The associate producers are Thor Thomsen and Peter Bennett.

I have a boostagram for you today. Listener uzza sent 333 stats and had the following comment. They said, 

This is the first time I’ve hear the word “principia” with a “k” ? indeed one result suggest [pri???k?piä]. but the rest goes more into [p??ns??pi??], [p??ns??pi??], [p_?_?_n_s_??_p_i?]. …troll job done for today ? nice episode, but expected to hear about the ricecorns and the checkerboard. one of the nicest in history. always great when educating people about compound interest and fiat money ?

Thanks, uzza!

First, the story of the grains of rice and the checkerboard is an apocryphal story. There is no evidence that it ever really happened. It is a great story to demonstrate just how fast things can grow exponentially, but there is no history behind it.

Second, the proper pronunciation for Principia Mathematica is “prinkipia”.

This is because the Prinkipia Mathematica is a Latin text. The whole book was written in Latin.

In Latin, the letter c is always pronounced as a hard c, like the letter ‘k.’ 

Principia, is an anglizied version. It is commonly pronounced that way, as most people don’t know Latin, but that wasn’t how Newton would have pronounced it.  If you watch any videos with science historians, I’d be the preferred pronunciation would be “prinkipia”. 

That being said, there are other Latin words with a ‘c’ that are usually not pronounced with a hard c. Caesar and Cicero would technically be pronounced Kaesar and Kikero, but we say Caesar and Cicero because that is what everyone knows them as, and it would just be pretentious and confusing to pronounce them in their original Latin. 

Remember, if you leave a review or send me a boostagram, you too can have it read on the show.