Lake Nyos is located in a volcanic area and is known to be a "soda lake", meaning it contains high levels of dissolved CO2. Under normal conditions, this CO2 is safely trapped in the deep water of the lake, but a disturbance can cause the gas to be released suddenly.
In the case of Lake Nyos, a landslide or volcanic activity is believed to have triggered a process called "overturning". During overturning, the deep, CO2-rich water rises to the surface and mixes with the air, causing the gas to be released rapidly. This can create a CO2 cloud that can spread over a wide area, suffocating any living creatures in its path.
The CO2 cloud from Lake Nyos descended into the valleys surrounding the lake, displacing the air and causing a loss of oxygen. People and animals who were exposed to the cloud died within minutes, without any warning or chance to escape.
The disaster could not have been predicted or prevented, as the scientific understanding of Lake Nyos and the potential risks of gas release was limited at the time. After the event, extensive research was conducted to understand the limnology and dynamics of Lake Nyos and similar soda lakes to prevent future disasters.
To mitigate future risks, a degassing system was installed in Lake Nyos to safely release excess CO2 in a controlled manner. This system has been operational since 2001 and has successfully prevented further gas build-up and potential releases.
