There are countless lakes around the world. You don’t have to look far to find one. They can be found on top of mountains, at sea level, or anywhere in between. They can be salt or fresh water, an endorheic basin or have an outlet, be ancient or artificial. They vary in depth, length, and volume. According to data provided by our satellites, there are approximately 100 million lakes of more than one hectare worldwide. And the largest rival the size of entire nations.
In addition, the ranking is constantly changing, as human activity can convert a massive body of water in a desert in just one generation. A graph published in Visual Capitalist collects the largest on the planet and compares them in scale with some countries in the world.
The largest lake in the world (and by far) is the Caspian Sea, a name that curiously already hints at its past, when was contiguous to the ocean about 11 million years ago. This huge saline lake, which is about the same size as Japan, borders five countries: Kazakhstan, Russia, Turkmenistan, Azerbaijan and Iran. It is estimated that 48,000 million barrels of oil are below the surface of the basin.
The five Great Lakes, which run the length of Canada and the United States border, form one of the largest collections of freshwater on Earth. This series of interconnected lakes represents about 20% of the world’s fresh water and supports more than 100 million people.
But surprisingly there is only one lake that contains as much fresh water as all the Great Lakes put together. A beast of its kind. Lake Baikal. Located in Siberia, it has a maximum depth of 1,637 meters. To give you an idea: the largest of the Great Lakes (Lake Superior) is only 25% deep (406 meters). Lake Baikal is unique in many other ways as well: it is the oldest and coldest in the world, and around 80% of its animal species are endemic.
A good way to get an idea of the size of these large watersheds is to compare them in size with some countries. This view of the Great Lakes over India helps us put its true size into perspective.
If we superimpose them on Central Europe, we see that they extend from the Netherlands to Slovakia. Lake Superior’s surface area of 82,000 square kilometers is similar in size to Austria.
Finally, let’s see what happens if we superimpose them on Australia, the sixth largest country in the world. Australia’s lack of glacial history means that there are few freshwater lakes in the country. Many of the larger ones only fill up during periods of excessive rain.
Constantly evolving
Not far from the largest lake in the world, straddling the border between Kazakhstan and Uzbekistan, are the dunes of the Aralkum desert. In the not too distant past, this harsh environment was actually the bed of one of the largest lakes in the world – the Aral Sea.
For both climatic and anthropogenic reasons, the Aral Sea began to decline in the 1960s. This evolution can be seen in an interactive NASA video. This drastic change in surface led the Aral Sea from the fourth largest lake on Earth to not even rank in the top 50.
Scientists note that size has fluctuated throughout history, but through the lens of modern history, these latest changes occurred rapidly, leaving local economies devastated and coastal cities landlocked.
Lake Chad in Saharan Africa and Lake Urmia in Iran face similar challenges, shrinking sharply in recent decades. Ultimately, it will be the size of our human footprint that will decide what these great lakes will look like in the years to come.