Lake Nyos Disaster

The lake Nyos disaster ouccured on August 21st 1986 when a limnic eruption at Lake Nyos, in northwestern Cameroon, produced a large cloud of carbon dioxide (CO2), which descended onto nearby villages, killing 1,700 people and 3,500 livestock.

The eruption triggered the sudden release of about 100,000–300,000 tons (some sources state as much as 1.6 million tons) of CO2.

It is not known what triggered the catastrophic outgassing. Most geologists suspect a landslide, but some believe that a small volcanic eruption may have occurred on the bed of the lake. A third possibility is that cool rainwater falling on one side of the lake triggered the overturn. Others still believe there was a small earthquake, but as witnesses did not report feeling any tremors on the morning of the disaster, this hypothesis is unlikely. Whatever the cause, the event resulted in the rapid mixing of the supersaturated deep water with the upper layers of the lake, where the reduced pressure allowed the stored CO2 to effervesce out of solution. It is believed that about 1.2 cubic kilometres (0.29 cu mi) of gas was released. The 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 oxidised by the air. The level of the lake dropped by about a meter and trees near the lake were knocked down.

Effects on survivors

One survivor by the name of Joseph Nkwain recalls the aftermath of the incident.

"I could not speak. I became unconscious. I could not open my mouth because then I smelled something terrible ... I heard my daughter snoring in a terrible way, very abnormal ... When crossing to my daughter's bed ... I collapsed and fell. I was there till nine o'clock in the (Friday) morning ... until a friend of mine came and knocked at my door ... I was surprised to see that my trousers were red, had some stains like honey. I saw some ... starchy mess on my body. My arms had some wounds ... I didn't really know how I got these wounds ... I opened the door ... I wanted to speak, my breath would not come out ... My daughter was already dead ... I went into my daughter's bed, thinking that she was still sleeping. I slept till it was 4:30 p.m. in the afternoon ... on Friday. (Then) I managed to go over to my neighbors' houses. They were all dead ... I decided to leave ... (because) most of my family was in Wum ... I got my motorcycle ... A friend whose father had died left with me for Wum ... As I rode ... through Nyos I didn't see any sign of any living thing ... When I got to Wum, I was unable to walk, even to talk ... my body was completely weak.

I can't even begin to imagine waking up from such a long sleep like that, only to find everything around me has died, that's pretty scary.

Since this incident happened they have installed a degassing system into the lake.


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