Lake Nios in Cameroon was formed just 400 years ago as a result of a hydrothermal explosion, when magma escaping from an abyss met groundwater. This part of the country is occupied by a volcanic ridge. A new lake filled the formed crater. For a long time the volcano was considered extinct. Despite the wonderful views from the shores of this alpine reservoir, tourists rarely looked here. Only a few villages were located nearby the lake, which has a height of more than a thousand meters above sea level.
The situation changed in 1986. About a relatively small (1,400 meters long and 900 wide) lake in Cameroon, the whole world spoke. In late August, almost all the inhabitants of the villages of Fang, Cha, Subum and Nyos died overnight. There were no pets, no birds, not even insects. Even the vegetation along the shores of the reservoir became brown and seemed frozen. Scientists called the incident "limnological disaster," and ordinary people began to call Nios "the killer lake." So what happened on that fatal evening of 08.21.86?
On the bodies of more than one and a half thousand dead, as well as eight hundred wounded, blisters were recorded. This gave rise to researchers to suggest that the volcano came to life. But reality turned out to be much more interesting. Lake Nios in Cameroon is truly volcanic, and carbon dioxide continues to flow from its crater and other microscopic slots into its waters . It accumulates in the bottom layers. Analysis of water extracted from the depths showed that immediately after the disaster, it was oversaturated with CO 2 , methane and helium. But the lion's share of toxic gases (96%) was still carbon dioxide.
At the end of summer, the area has a rainy season. Most likely, cold and dense water brought by precipitation and numerous streams overwhelmed Lake Nios. There were so many of it that it completely covered the surface of the water area, forming a surface layer. In the depths, warm water saturated with poison gas rested. The difference in layer density was the trigger that launched the catastrophic chemical reaction. On the evening of August 21, a strong north wind blew, which drove the rainwater south. Opened bottom layers immediately began to emit gas. We see a similar reaction, uncorking a bottle
ku with soda. Only the scale of what was happening was much larger.
As a result, Lake Nyos in Cameroon was shrouded in fog. Gas escaped to freedom absorbed energy, as a result of which the air temperature dropped to ten degrees in a matter of seconds. The bubbles were so huge that they created a small tsunami that flooded the southern regions. And in the north, a cold poisonous fog crept along the valleys, bringing death to all living things.
Now Lake Nyos in Cameroon looks pretty cute and picturesque. But tourists come here only in one category. These are those who like to tickle their nerves. Indeed, new water measurements made in 1992 showed that CO 2 again began to flow into the bottom layers of the lake. Who knows how the natural conditions will turn out, and will not the deadly chemical process start in the near future?