Lake Vostok in Antarctica is the largest lake under the ice on the planet; it is about 250 km long and 50 km wide and is buried under four kilometres of ice. It is known by the name of the old Soviet Station where one of the projects – on longer geological research and greater impact since the commencement of space exploration – began the study of paleoclimate records taken from ice in the 1970s:.
After years of preparation, in February 2012 the 5 G drilling programme, which had begun in 1990, reached Lake Vostok and the first samples were taken of the lake water, which could harbour unknown life forms isolated within the lake for millions of years.
The surface of this lake is about 500 metres below sea level, deeper than the Dead Sea, with a maximum depth of 510 metres; the lake bed is more than a thousand metres below sea level.
Lake Baikal, known as the Pearl of Siberia, is the largest reservoir of fresh water on the planet, and its 23,615 km3 represent a quarter of all river and lake fresh water. With its 1,642 metres of maximum depth, Baikal is also the deepest lake on the planet. And since the surface of the lake is some 455 metres above sea level, its chasms are located almost 1200 metres below the surface level of the oceans!
The Dead Sea. This endorheic lake – it means that the water does not flow into any river but only receives contributions – is one of the historic lakes of biblical history and the cities of Sodom and Gomorra are supposed to have been on its shores.
Due to its endorheic nature and high evaporation, the waters of the Dead Sea are highly saline, eleven times more so than the ocean, which gives them a high density (1.240 g/cm3, compared to 1.027 g/cm3 seawater and 1 g/cm3 freshwater) that prevents almost any type of animal life and gives high buoyancy to those who bathe in its waters.
The Dead Sea shores have their surface land deepest below the ocean level – 416 metres – and in recent decades the lake has suffered a gradual decline in water level due to consumption of the River Jordan – Its principal tributary – and also because of the artificial salt in the lake itself, its water surface level decreasing by one metre per year. However, the Dead Sea receives a growing number of tourists who come attracted by the healing properties of the water, steam, mud and even high atmospheric pressure of the hollow.
The Plitvice Lakes are a small group of 16 lakes stepped in terraced formation connected by rivers and waterfalls in a karst landscape of breathtaking beauty. The lakes are in the Plitvice National Park in Croatia, which retains a variety of lush native forests and great animal diversity, all of which makes it one of the most beautiful natural parks in Europe.
The Caspian Sea, with its 372,000 km2, larger than Germany, is the largest intercontinental water surface on the planet and its 69,400 km3 of water, making up about 40% of the volume of water accumulated in all the lakes in the world. However, for its size and brackish water, it has been considered a real sea, as its name suggests. In fact, about 6 million years ago, the Caspian was part of the Tethys Ocean, which then connected the Atlantic and Indian Oceans and was closed by the collision of Africa and Arabia with Eurasia; the Mediterranean, Black and Caspian Seas being remnants of that great now-disappeared ocean.
Perhaps some geographers in old Greek and Roman days understood this old geological connection when pondering the underground water currents which linked the Black and Caspian Seas and regulated water levels in both seas. And though it may seem shocking, today scientists have established a more remote connection with the North Atlantic Ocean, as the natural fluctuations of the water level of the Caspian Sea are related to the North Atlantic Oscillation (NAO), which regulates climate in this area and, indirectly, the rains in the drainage basin of the River Volga,, the main tributary of the Caspian Sea.
Even stranger is the fact that present-day diplomacy is attempting to return the Caspian Sea to its marine nature, as some countries on its seaboard want to take advantage of the different legal treatment of sea and lake waters, to be granted rights to transport and operate oil resources located around this large brackish lake.
Lake Chad – the word means 'lake' – is one of the most spectacular examples of the fragility of natural systems subject to the influence of climate change and human activity.
Lake Chad is a shallow endorheic lake located in a flat area of the Sahel, therefore subject to intense evaporation, and small changes in its volume of water result in large gains or losses of extension.
About twelve thousand years ago, Chad was practically dry, but during the next five thousand years, as the planet’s deglaciation was accelerating, Chad began to increase its size, reaching an area of about 400,000 km2 6,500 years ago, in the phase known as optimal climate – In which the Earth had a global temperature slightly higher than today. Thereafter, with the increasing aridity of the climate and the subsequent expansion of grazing and agriculture, Lake Chad was losing extension, though in the nineteenth century it was still one of the largest in the world. In 1960, however, the extension of the lake was about 25,000 km2 and in the thirty yeas since it has decreased to only 1,500 km2. Today, some 30 million people depend on 70 km3 of water from Lake Chad, which has a maximum depth of 11 metres and an average depth of 1.5 metres.
Lonar Lake, in the region of Maharashtra, India. It is a small circular lake 1.2 km in diameter and located in the crater of a meteorite impact. As the plain where the meteorite fell is formed by basaltic rocks, it was first thought to be a volcanic crater, but today its extraterrestrial origin is beyond question, the event having been dated at 52,000 years ago.
For its size and excellent preservation, Lonar Crater is an excellent example of a meteorite crater and there are many Hindu temples and archaeological ruins in its surroundings, so that it is a good tourist attraction. But the lake itself also has genuine interest for limnology – which is the scientific field that deals with the lakes – as it is a hyper-salty and hyper-alkaline lake with a pH of 10.5, close to the tolerable limit for extermophiles organisms. One of the most remarkable qualities of this lake is that its water, despite its deep blue-green colour, barely has transparency.
Salt Flat of Uunyi, in the highlands of Bolivia, at about 3,665 metres altitude, is the largest salt flat in the world, with an area of 12,000 km2. This giant salt lake is the result of the drying of ancient now-disappeared lakes, the remains of which are thin sheets of water which remain on the fringes of this vast salt flat.
Five Flower Lake is a small lake considered one of the most beautiful in the world for its amazingly transparent water in a spectacularly beautiful environment of fabulous colours. It is located in the Jiuzhaigou Valley, in the region of Tibet in China, and was declared a World Heritage Site by UNESCO for its outstanding landscape and historical value.
The Badain Haran Desert Lakes, meaning 'mysterious lakes', are more than a hundred small lakes with an area of 1.5 km2 located in a large sandy desert among dunes hundreds of metres high, the highest stable dunes on the planet. The contrast between the giant dunes and the permanent lakes, in a desert with an average rainfall of only 40 mm per year, is certainly a spectacle of mysterious beauty, though today it is known that water flows under the dunes from the mountains located several hundred miles west. The waters of these lakes are either fresh or salty.