Lake Nyos, the lake area which contained in the region of Cameroon, West Africa. This lake reaches a depth of 157 m with the deepest 208 meters. There are many people living around the lake Nyos valley.
However, in 1986, there were peculiarities in residential areas. About 1700 person died suddenly and simultaneously. Even more strangely, all the people who died were killed in a position while performing their daily work.
One was killed while pumping water, cooking, and some are killed while drinking a glass of water. Some survivors of the incident described what happened on the day the person died.
He said, the night before the incident, suddenly the air was warm and smelled like rotten eggs. The community is not too concerned about it. And suddenly the next morning, a lot of corpses when getting busy with their daily activities.
No one knows for sure what caused the strange death. However the experts found that the color of the water of Lake Nyos changed from clear to bright orange color.
To search for an answer, the experts then examined Craten Lake in Oregon. This lake is the largest lake in the number seven world. The extent of 50 square kilometers with a depth of 594 meters. So described if the Empire State entered into this lake, it will sink.
Craten lake holds about 19 trillion liters of water. Approximately 7700 years ago, Mount Mazame the place erupted and threw the top of the mountain. Crater Lake is then formed Craten.
However, it remains Mazame volcanic activity affecting the lake. Because under the lake was still there the former magma pools that still remain heat.
The experts found that the water temperature at the bottom of the lake a few degrees warmer, the salt levels are also ten time more concentrated and contains a lot of CO2. And CO2 is then seeped from the crevices of the earth's crust and into the crater that has now become a lake.
However, the presence of water has prevented the rise of CO2 into the air. Even if there is a little loose, still carried by the wind can be lost. So it is not too dangerous.
The process also greatly affect the change of seasons. In winter, the velocity of the water will be pushed down because of warmer temperatures below. Conversely in the summer, the velocity of the water will rise to the top.
The cycle is then made the emergence of the water layers of different density levels. The lowest layer of water is more concentrated than the above. In the bottom layer of water that is flowing from the bottom of the CO2 retained earth.
CO2 can not rise higher because of differences in water density in the layer above it. So gathered and accumulated over decades and become very much in the bottom water layer.
This phenomenon was later found also in Horseshoe Lake is smaller than Lake Craten. The trees that grow around the lake dries up and eventually die.
After investigation, it turns out CO2 levels in the lake is up to 100 tons / day and soak into the ground. This is what makes the trees around them die. The experts then conduct experiments to dig a little dirt on the lake and tried to light a fire.
However, due to its pekatnya CO2 levels, the fire was extinguished immediately brought closer to the ground. It turned out that the accumulation of CO2 that has been very much on the lake finally overflowed and caused the lake to be very dangerous.
However, CO2 levels at Horseshoe Lake is not too harmful to humans, because it limits the harmful levels are 1.75 million tonnes. And this will only happen in the event of the mountain erupted.
Discoveries is then helped the experts to conclude what happened at Lake Nyos. The night before the event, there is a cliff on the banks of the lake, collapsed and went into the water.
It is estimated this cliff ruins have shaken the water layers. So the most basic layer is filled with CO2 to rupture and drain large amounts of CO2 to the surface of the lake.
The next morning the flow of CO2 are then enters the settlement. And because CO2 is colorless and odorless, people are not aware of his arrival. That is what causes a lot of people who died while doing daily activities.
CO2 is like a killer who is stalking silently. Perhaps only a few people are aware of the dangers that are invisible on the bottom of the lake that looks very beautiful on the surface.
Without them knowing it, their excuse inhaling CO2 that comes from the most basic layer of the lake, which has been accumulated over decades. And plenty of people who died because of it.
Read More Other Unsolved Mysteries article!