2. Fact: Lake Nyos is a crater lake above a magma chamber
Under normal conditions CO2 is released gradually
from the magma chamber into the lake
Volcanic eruptions release large quantities of
poisonous gases such as CO2
3. Fact: Lake Nyos lies above a constructive plate boundary
There are 3 lakes in the
world saturated with CO2
Large events such as earthquakes
and landslides can causes gases
to come out of solution
4. Fact: underwater volcanoes heat overlying water and disturb sediment
Lake temperature was found
to be unchanged
The bottom 80m of water
was free of sediment
5. Fact: the lake was turned red/brown in colour following the disaster
Lake sediment had a high
iron content
But - only the top 10m of
water was discoloured
6. Fact: survivors reported feeling warm and smells of rotten eggs
Tests on US fighter pilots
have revealed that CO2 at
concentrations of >6% acts
as a sensory hallucinogen.
7. Fact: victims’ bodies were found to be covered in burns
Dry ice
Deep water is very cold.
8. Fact: people travelling on the back of a pick-up truck survived but the driver died
CO2 is more 1.5 times as
dense than air
9. Fact: dead bodies showed no sign of struggle
"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 on my motorcycle . . . As I rode . . . through Nyos I didn't see any sign of any living
thing . . . I was unable to walk, even to talk . . . my body was completely weak.“ a survivor’s report
1700 people died
4000 livestock died
All animal life died
Including insects
Many people and animals appear
to have died in their sleep
10. Fact: people living nearby reported hearing a loud explosion
and/or
A storm resulted in a long
period of heavy rain
11. Fact: low level white cloud was observed above the lake and surrounding countryside
The cloud remained
very close to ground
level and seemed to
‘flow’ like water
12. Fact: usually CO2 is naturally dissipated into the atmosphere by currents in the water
Crater lakes are often very deep and surrounded by steep sides
