We hear about tsunamis, earthquakes and even the occasional tornado but what we don’t hear about are lakes that kill. Carbon dioxide is not only deadly when concentrated, but it naturally occurs in large amounts right below the surface of the earth. What happens when large concentrations of carbon dioxide erupt? This strange but true story will expose the hidden dangers of natural gases on a ticking time bomb.
On August 21, 1986, Lake Nyos in northwestern Cameroon killed 1,746 people and 3,500 livestock within a 24 hour period. On the night of this disaster, a farmer by the name of Ephraim Che heard a loud rumble. Epraim thought it was a simple rock slide due to a mist eruption in the lake directly near his home. The farmer proceeded to take him and his children inside because he started to feel ill and it looked as if rain was approaching.
Over 400 cattle died overnight from carbon dioxide poisoning
When morning came, Epraim headed down to the lake to see what damage the rock slide had caused. Epraim stood in horror when he realized it wasn’t a rock slide that had caused the rumble, but a disaster he had never seen before. A normally blue lake turned to a dusty red sea of de̳a̳t̳h̳. 31 members of his family and over 400 of his cattle were dead. Epraim then realized he didn’t hear any birds, chicken, cattle or the normal bustle of each morning. There was virtually little movement in his tiny village, not even a fly buzzing above the fallen cattle.
That rumble Epraim heard killed was actually a deadly gas eruption of carbon dioxide that killed 1,800 members of his community silently while they slept. Scientist flocked to what seemed to be an almost biblical revelation and soon found that the lake was not only deadly, but townsfolk had foretold such an occurrence for generations. Natural occurrence, Biblical or completely man made? lets talk about what a volcanic lake actually is.
Carbon Dioxide Poisoning
The scientific community is still trying to understand the full effects of carbon dioxide in the body, but here’s what we know. Carbon dioxide causes severe acidosis which increases the effects of parasympathetic nerve activity. It does this by interfering the hydrolysis of acetylcholine by acetylcholinesterase, resulting in a depression of the respiration and the circulation. Concentrations of more than 10% carbon dioxide may cause convulsions, coma, and de̳a̳t̳h̳. Concentrations of nearly 5 gallons per every gallon of water was dissolved in Lake Nyos.
Within 2 hours of being exposed to levels of carbon dioxide (10% of higher) could cause de̳a̳t̳h̳. If there’s a lot of carbon monoxide in the air. Long-term exposure to low levels of carbon monoxide can also lead to neurological symptoms, such as: difficulty thinking or concentrating. Treatment for carbon dioxide poisoning either finding fresh, untainted air or using a hyperbaric chamber that creates clean, pressurized oxygen.
Lake Nyos is considered a volcanic lake even though it is not directly above or below a volcano itself. Volcanic lakes often carry large amounts of carbon dioxide below the surface. Depending on the type of lake, layering can occur, which means that deeper water never reaches the surface, therefore never releasing any carbon dioxide making it inactive and dormant. Much like volcanos, they need outside geological activity to become active.
Lake Nyos after the eruption
A limnic eruption, also called a lake overturn, is a rare type of natural disaster in which dissolved carbon dioxide gas suddenly erupts from deep lake waters. The eruption forms a gas cloud that can suffocate wildlife, livestock, and humans. It can also cause tsunamis in the lake as the rising carbon dioxide displaces the water. Scientists believe earthquakes, volcanic activity, or explosions can be a trigger for such an explosion. Some clues as to limnically active lakes include: Carbon dioxide saturated incoming water, a cool lake bottom indicating an absence of direct volcanic interaction with lake waters, an upper and lower thermal layer with differing carbon dioxide levels, and proximity to areas with volcanic activity. All of which are possible indicators of a limnic lake.
Prevention Methods: Will it happen again?
Three fountains installed at Lake Nyos to relieve carbon dioxide buildup.
The tragedy at Lake Nyos created a public outcry for answers and preventive measures. The best solution to prevent limnic eruptions was to install pipes to remove the gases from along the bottom and allow the carbon dioxide to leak out in safe quantities. Three man-made fountains in the lake are the visible parts of those vent tubes, the last of which was vertically installed in March of 1999. The process ended in 2001 and proceeded slowly because of funding problems. Scientists say over the next two years, the pipes will pump out some 200 million cubic meters of trapped carbon dioxide.
Michael Halbwachs is the head of the French gas-extraction company DATA Environment. He says the process will eradicate all lingering dangers of another explosion, leading to a sudden release of carbon dioxide. Time is the only way of telling if the measures are actually working due to the eruptions being spontaneous. His team of scientist are hopeful this will prevent future limnic activity.
Africa and parts of Asia are two promising places to see limnic activity again but on a much larger scale. Even with the measures listed above, carbon dioxide poisoning through ground water is still a major concern that has yet to be remedied. Dams are also being used on Lake Nyos but dangerous bodies of water like Lake Kivu, in Rwanda is one of the largest and deepest lakes in Africa and it has nearly 2 million people living near its shores. Lake Kivu, to date, is filling up with carbon dioxide below the surface and it will only take one occurrence, like and earthquake, to set it off. Millions of lives will be at risk if we aren’t able to figure out a more lasting fix on a silent killer that only needs a small shift in the earth to kill.
In some parts of the world cattle have died overnight, and in these areas locals have blamed a̳l̳i̳e̳n̳ intervention for the dead cattle. What do you think?
Scientific theory in the Smithsonian Magazine.
There is also the Biblical theory of these Killer lakes, which has its own perception.