It happened twice in the 80's, and there's another, much larger lake in Africa, that scientists are worried may explode the same way. Limnic eruptions, sometimes called a "lake overturn", is a rare natural disaster in which a deep body of water experiences a sudden change in pressure, causing massive disruptions of the water, and releasing a deadly cloud of Carbon Dioxide to finish the act. Ready to learn more about what makes these lakes blow up? Find some high ground, kick up your feet, and get ready for some Super Cool Science S#!t!
If enough of this gas gathers at the lakes bottom, and something like a nearby tremor jostles the lake, the CO2 can suddenly undissolve, and the effect is like popping the top on a can of soda, except this can of soda contains millions of gallons of carbonated water...
All that carbon dioxide that was dissolved at the bottom of the lake rushes up just like the bubbles in that soda can. This rush of gas displaces a lot of water, and can cause enormous tsunamis that crash into the shores of the lake.
CO2 is lighter than water, but heavier than air. After swelling up to the surface of the lake, it creates a cloud of carbon dioxide that hugs low to the ground, pushing breathable air up, and suffocating everything in it's path.
Lake Nyos. Source
Lake Monoun, in the African country of Cameroon, erupted and killed 37 people in its vicinity. Two years later, the country would see of neighboring Lake Nyos erupt in a fury like the world had never seen. An article from the BBC, published in 1986, reported the natural disaster, and describes scientists' confusion as to its cause;
At least 1,200 people are feared dead in Cameroon, West Africa, after a cloud of lethal gas escaped from a volcanic lake.
The tragedy happened at Lake Nyos, about 200 miles (322 km) northwest of the capital, Yaoundé, during the night.
Most of the victims died in their sleep.
The gas killed all living things within a 15-mile (25km) radius of the lake, and the area is still highly contaminated.
At the time, no one had any idea what had happened. Some believed a volcanic eruption occurred under the lake which released the gas cloud, though that point was debated, as the volcanic crater the lake is contained within had been declared extinct. Those who survived the initial disaster where described to have been "poisoned"
A doctor there said they had been poisoned by a mixture of gases including hydrogen and sulphur.
He described the symptoms, including burning pains in the eyes and nose, coughing and signs of asphyxiation similar to strangulation, as like being gassed by a kitchen stove.
This video is not for young eyes, though most of these SCSS posts aren't either...
Lake Kivu lies on the border separating the Democratic Republic of the Congo and Rwanda. It is roughly 2000x larger than Lake Nyos, and is thought to have the same potential to erupt. If it does, scientists predict that casualties will number in the millions.
Lake Kivu also contains large amounts of methane gas, and it's likely that if it erupts, it could produce enormous fiery explosions to accompany the asphyxiating cloud of gas, not to mention to giant wall of water that would crash into the highly populated shores of this lake.
In order to prevent future limnic eruptions, scientists are installing "vents" that pump CO2 saturated water from the bottom of the lake up to the surface, helping to balance the lake. This process is called "degassing", and helps to release some of the trapped carbon dioxide, in an effort to prevent the conditions that would lead to an eruption, and save countless lives.
While incredibly rare, limnic eruptions are a serious threat to those who live in an area that could be affected by one. Scientists are doing everything they can to learn more about this phenomenon, and how to prevent it from happening again.
