On 21, August 1986 In Cameroon, a small crater “Lake Nyon” killed 1,700 villagers and 3,500 livestock overnight when it abruptly released 100,000 - 300,000 tons of carbon dioxide suffocating everything within 25 kilometers. However, as per geologists, the reason might have been a landslide, a small volcanic eruption on the bed of the lake, or a small earthquake. Moreover, a third probability is that cool rainwater falling on one side of the lake triggered the overturn. In spite of all the theories, no actual reason had been found up to now.
Scientists still don’t know what triggered the misery Lake Nyos in northwestern Cameroon a large cloud of carbon dioxide formed, rose at nearly 100 kilometers per hour, and spilled over the northern lip of the lake. It descended down two valleys, displacing all the air and suffocating people and livestock within 16 miles of the lake. Even now, the reason of this catastrophic disaster out-gassing has not been revealed. Therefore, a degassing system has since been set up here with the object of decreasing the concentration of CO2 in deep waters and therefore the risk of further eruptions.
Therefore, it is thought that more than 1.2 cubic kilometers of gas was released. Though, normally blue waters of the lake turned a deep red after the outgassing, due to iron-rich water from the deep rising to the surface and being oxidized by the air. The level of the lake dropped by about a meter and trees near the lake were knocked down. After catastrophic eruption, many survivors were treated at the main hospital in Yaoundé. So, it was well believed that several of the victims had been poisoned by a mixture of gases that included hydrogen and sulfur. Poisoning by these gases would lead to burning pains in the eyes and nose, coughing and signs of asphyxiation similar to being strangled. Although, scientists concluded from evidence that a 100 m column of water and foam formed at the surface of the lake, spawning a wave of at least 82 ft that swept the shore on one side.
In 1995, a feasibility report was successfully conducted, and the first permanent degassing tube was installed at Lake Nyos in 2001, and two more pipes were installed in 2011. After disaster, scientists researched on other African Lakes to observe any similar phenomenon could happen elsewhere. In Congo, “Lake Kivu” which is 2,000 times bigger than Lake Nyos, was also found to be supersaturated, and geologists found evidence that outgassing events around the lake happened about every thousand years. Cameroon marks 30 years since its worst natural disaster ever, appear to be completely dead. There is no sign of birds or other animals. In the 1980s, the population of Nyos was over 3,000 and rising fast as a lot of people moved to the area for agriculture and cattle ranching. So, after 30 years, the population is still estimated at several thousand, but they live far from the killer lake, even though many are ignoring warnings from the government and returning closer to the lake. Source: Charismatic Planet