Whats the deadliest lake on Earth?

Though many lakes are marked by calm waters and serene surroundings, this can change in an instant. Heaving waves and high winds caused by extreme weather can change any water body into a dangerous location.

Other, more rare lakes don’t need weather to be hazardous to visitors. These five deadly lakes were made so by natural processes, with just one exception.

Lake Karachay

Located in western Russia, Lake Karachay was a dump site for radioactive waste for decades. Most of the waste came from a nuclear plant in nearby Mayak. In 1990, the Natural Resources Defense Council estimated that the lake contained radiation levels high enough to give humans a lethal dose within an hour. Other estimates say five minutes is long enough.

Lake Karachay (referenced as Lake Karachai) as seen from space, April 2010. (Credit: NASA)

Boiling Lake

Dominica’s Boiling Lake is filled with greyish-blue water and is most always engulfed by vapor. This is because water in the lake is super-heated by an opening in the Earth’s crust. Temperatures reach nearly 200 degrees Fahrenheit in the water body and it is the second largest hot lake in the world.

Dominica’s Boiling Lake. (Credit: Wikimedia Commons User Pembo13 via Creative Commons)

Lake Kivu

Thousands of years ago, volcanic activity separated Africa’s Lake Kivu from nearby Lake Edward, shifting its flow south. Kivu sits some 5,000 feet above sea level and is biologically poor. Its lakebed holds dissolved methane gases and it has experienced limnic eruptions in the past, a natural disaster marked by an eruption of dissolved carbon dioxide.

Lake Kivu. (Credit: Adam Jones via Creative Commons)

Horseshoe Lake

California’s Horseshoe Lake sits near Mammoth Mountain, where a series of earthquakes occurred in the early 90s. After those quakes, scientists began noticing an increase in tree death around the lake. Further investigation revealed that extremely high concentrations of carbon dioxide were escaping from the soil and killing the trees. There are 100 acres of dead and dying trees near the lake today.

A tree kill area near Horseshoe Lake/Mammoth Mountain, 2011. (Credit: U.S. Geological Survey)

Lake Nyos

Resting in a crater on the flanks of an inactive volcano, Lake Nyos sits above a pocket of molten rock. Carbon dioxide from below saturates its water, making it vulnerable to extreme turnover events and limnic eruptions. Its volatility was marked by a 1986 turnover that released toxic gas, killing thousands in Cameroon.

Many of nature's wonders hold a dangerous secret underneath their beauty, and the same goes for the lakes. While a few hide their threats in plain sight, others will surprise you when you expect it the least. So without further ado, let's see the top ten list of most dangerous lakes on Earth.

10. Lake Kaindy, Kazakhstan

The beautiful lake Kaindy was created after the 1911 earthquake, as a landslide formed its basin, submerging the forest. Even during the summertime, water temperature is around 43°F, while the dead tree trunks gave it a nickname "Sunken Forest." The lake changes color from blue to green, and the crystal clear liquid allows you to see underwater from the shore.

The lake isn't very dangerous if you can swim in ice-cold water, but the algae, plants, and the submerged trees can be tricky obstacles. However, we think it deserves a place on our list because of its eerie yet spectacular scenery.

9. Boiling Lake (Dominica)

Located at the heavenly Caribbean Island of Dominica, Boiling Lake keeps a deadly secret, as it can kill anyone who dares to enter its waters. With temperatures between 180 and 197ᴼ Fahrenheit around the edges, it's no wonder that no one dared to measure the warmth at the center of the lake.

Even though the heat can go down, the water is unpredictable, as it may start to boil at any time, releasing harmful gases such as carbon dioxide.

Therefore, due to high temperatures, the air in the area is hot, steamy, and moist, with sulfur's smell everywhere.

8. Horseshoe Lake, USA

Settled up in the Sierra Nevada mountains, Horseshoe Lake is a part of the City of Mammoth Lakes, created upon a volcano. This location has a creepy secret, as the soil around it contains high carbon dioxide and hydrogen sulfide levels, posing a threat to the trees and people.

The gas from the cooling magma beneath the lake comes to the surface through the terrain's cracks. To illustrate how dangerous it can be, let's say that back in 2006, three people who took shelter in the cave near the lake died from carbon dioxide poisoning.

7. Lake Nicaragua, Nicaragua

On the border of Costa Rica and Nicaragua is the largest freshwater lake in Central America, Lake Nicaragua. There is nothing unusual about it at first glimpse, except bull sharks inhabiting it! Therefore it could be dangerous to swim in these waters, as these animals are unpredictable, aggressive, and will eat everything. Even though only three lethal attacks on humans are reported, we wouldn't recommend swimming there.

At first, scientists were misled that this is some endemic species. However, later they discovered that the same sharks have been seen in the Caribbean Sea and Lake Nicaragua. Therefore, it was found that the bull sharks swim upstream the San Juan River, crossing a distance of over 120 miles and adapting to freshwater.

6. Lake Kivu, Rwanda

This lake, located in Rwanda on the border with the Democratic Republic of the Congo, has carbon dioxide deposits in its volcanic rock bed. Moreover, add to that 55 billion cubic meters of methane gas produced by the lake bottom's bacteria, and you'll get the deadly combination. There are only three exploding lakes worldwide, but Kivu is the largest, making it the deadliest one. 

Any disturbance of the terrain, such as an earthquake or volcanic activity, can put two million people around the lake at risk. Rwanda uses the gases to produce electricity and pumps it out of the lake, but this is only a small discharge. Therefore, the lake stands still for now, and we can only hope that it will stay that way.

5. Lake Monoun

Lake Monoun is located in Cameroon at the volcanic field. At first glance, it's peaceful and beautiful, but it holds a deadly secret. Hence, Monoun Lake is one of three exploding ones on Earth. Due to the limnic eruption, the lake erupted without warning back in 1984, killing 37 people after releasing a massive amount of carbon dioxide.

The limnic eruption works much like a can of soda. The gas is on the bottom of the lake, as any disturbance of the terrain can release it and make it explode, much like the soda can when you shake it before opening.

4. Lake Natron (Tanzania)

The magnificent reddish colors of Natron Lake in Tanzania are quite alluring. Water is oversaturated with salt, and the red color is coming from the algae. However, the beautiful lake is among the most terrifying wonders of nature. The danger lies in high pH levels that are so corrosive that they can strip ink from dyed materials! 

The pH level of water is extremely high, as it reaches up to 12pH, with the temperatures extend above 104º F. Such a high amount of acid can mummify unadapted animals and turn them into stone. Moreover, high levels of acid can cause chemical burns to human skin.

3. Lake Michigan, USA

The five Great Lakes are situated on the border of Canada and the United States. One of those lakes, Lake Michigan, the third-largest one, is considered highly dangerous, but it's very popular despite this. The threat comes from enormous undercurrents, which cause few deaths each year. 

Lake Michigan's shape makes it particularly predisposed to dangerous rip currents, as the docks and piers only amplify this problem, causing injuries and even deaths. Moreover, due to sudden and substantial air and water temperature changes during October and November, currents and waves become more lethal. Regardless of the warnings, swimmers still love the lake's waters, and the death toll keeps getting bigger. 

2. Laguna Caliente, Costa Rica

Laguna Caliente in Costa Rica is among the most acidic natural lakes on Earth. Its size varies a lot, as it can be up to 160 feet deep or disappear entirely. Water temperatures also change from 71°F to 200°F, while the colors go from emerald green to gray and yellow. The yellow appearance comes from the floating liquid sulfur.

Moreover, due to its location in a volcanic crater, the lake often creates eruptions, much like giant geysers. Therefore, thanks to the high levels of acid (larger than in car batteries) and frequent explosions, it forms acid rain and fog, causing the devastation of flora around the lake. Consequently, it can also be harmful to humans.

1. Lake Nyos

Lake Nyos in Cameroon has the reputation as the deadliest in the world. In 1986, due to a limnic eruption (see number five on our list), the lake exploded, releasing a carbon dioxide cloud. As this gas is heavier than oxygen, it stayed close to the ground, as it slowly drifted to the villages in the valley, causing death to more than 1700 people and over 3000 livestock.

This was the first known case of massive asphyxiation caused by natural events a not by men. Once a beautiful blue lake became murky brown because of carbon dioxide saturation. The government built a degassing station in the lake to prevent future disasters.

Finally, we would like to mention one more lake, even though it doesn't exist anymore. Once, the beautiful mountain lake Karachay in Russia was the deadliest one in the world. This was because it became a dumping location for radioactive waste from a nuclear plant nearby. It was so radioactive that the ten minutes spent nearby could cause severe health issues. However, today it's entirely infield and sealed with concrete to prevent any more damages to its surroundings.

Have you visited some of these top ten dangerous lakes? Please write to us in the comment section, as we would like to hear your thoughts.

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