In the early hours of August 21, 1986, Lake Nyos in northern Cameroon, Africa, suddenly made a loud noise, and in the following hours, more than 1,700 people in the villages near Lake Nyos died, some poultry also died, and only a few survived. So what is inside Lake Neos, and why is such a strange and terrible event suddenly happening?
Located in northern Cameroon in Africa, Lake Neos is one of cameroon's main lakes.
It is located on the slopes of the Patmetta Plateau, and from a distance, it looks like a blue gem set on the hillside, and the sun shines down and sparkles, which is very charming, so it has always been a famous local tourist punch card.
Because of the abundance of water resources, there are many villages around it, and the villagers here are surrounded by mountains and rivers, and have lived on Lake Nyos for generations.
Looking at Lake Nyos from the heights of the village, the water surface is flat like a mirror, and wisps of white smoke rise from the surface of the water from time to time, and the villagers have always thought that it is fog, which is like a fairyland with the jungle trees around Lake Nyos.
In the mountain range where Lake Nyos is located, there is a volcano, Lake Nyos is located on the crater, but this volcano is an extinct volcano, so Lake Nyos has always been very calm, and people have not studied it too much.
However, under this enchanting scenery, local villagers often see the carcasses of animals near Lake Nyos, either at the lake or at the foot of the mountain, and these animals have no obvious trauma, as if they are asleep.
But the villagers always thought that this was a normal phenomenon, so they did not take this matter to heart. After all, the people and poultry in the village are still fine.
While people were still enjoying a comfortable life, in the early morning of August 21, 1986, a loud noise completely changed the lives of locals.
Lake Nyos erupted suddenly with a loud noise, the water column erupted at a speed of up to 100 kilometers per hour, and some unknown gas was filled with the air, and the concentration was very high. Soon the gases formed a deadly cloud layer 50 meters thick, covering an area of up to 23 kilometers.
Villagers in the village near Lake Nyos were still asleep, and some were awakened by a loud noise, but soon lost consciousness again.
Recalling the situation, one survivor said he suddenly smelled a pungent and strange smell in his sleep and found it difficult to speak when he opened his eyes.
At the same time he heard his daughter making a particularly eerie and strange sound. He wanted to go to his daughter's window, but his body was out of control, and before he could stand, he fell to the ground and became unconscious.
It wasn't until 9 o'clock in the morning that the survivor woke up with a sharp knock at the door, he struggled to open the door, saw some friends, wanted to speak, but still couldn't open his mouth, and it was very difficult to breathe.
When he went to look for his daughter again, he found that her daughter had died a long time ago, and many people had died in the village.
Then the survivor was taken away by his friend, and when he left the village, he found that the village that was good yesterday suddenly seemed to be evil, most of the people died mysteriously, and the village was surprisingly quiet, unusually terrible.
Later, according to the statistics of the relevant departments, a total of 1700 people died that night, and the poultry in the village was completely destroyed.
When the survivors recalled the events of that night, most of them mentioned that there was a loud noise in the direction of Lake Nyos, and when they evacuated, they also found that the water of Lake Nyos had turned a strange brownish red, which made many villagers think that the gods under Lake Nyos were angry and became "Lake of Killing".
For a time, people were panicked and rumors were spreading.
After the incident, the Government of Cameroon attached great importance to it.
What is it that makes such a bizarre disaster? Pay attention to the public number is not silent, every day to push strange talk, naturally not the villagers said the gods, in order to find out the truth, the Cameroonian government not only sent its own scientists, but also invited international authorities to investigate the incident together.
George Kling USGS scientist Bill Evans, a professor at the famous University of Michigan in the United States, was the first to arrive at the site and went straight to Lake Nyos.
According to the survey, at 6 o'clock in the morning, wisps of mist rise on the surface of Lake Nyos, which has been used before, but the villagers have always thought that it is a small drop of water. These mists are constantly gathering in clumps and drifting toward the shore, and when people breathe in, they feel dizzy and nauseous and their limbs are weak.
During the time period from 8 to 10 o'clock, these fog concentrations are the highest, and once inhaled, there is a fatal threat at any time. It wasn't until after 11 o'clock that the fog slowly dissipated and Lake Nyos returned to normal.
Is the death of the villager related to these fogs, and what are these fogs?
Based on the survivors' recollections and related investigations, scientists inferred that the extinct volcano below Lake Nyos erupted, so people would hear a loud noise in the early morning of the 21st.
So why does the lake turn brownish red? Investigators decided to drain the lake to find out.
There are a large number of hot springs at the bottom of and near Lake Nyos, and the springs contain a lot of carbonic acid, and these springs that continue to flow into Lake Nyos continue to increase the concentration of carbon dioxide in Lake Nyos, with an annual carbon dioxide content of up to 5 million cubic meters in the lake.
As a volcanic lake, Lake Nyos is actually very different from ordinary lake water, and its lake water dissolves a large amount of gas, in addition to a large amount of carbon dioxide, there are many highly toxic gases of hydrogen cyanide and its extensions.
In addition, Because Lake Nyos has been in a quiet state for thousands of years, the high concentration of carbonic acid and the divalent iron at the bottom of the lake combine to form iron carbonate minerals, that is, rhodite, which appear reddish-brown.
On August 21, by chance, the extinct volcano under the water of Lake Nyos erupted, and the huge impact made Lake Nyos make a loud noise.
Subsequently, the carbon dioxide and other toxic gases that were originally dissolved in the lake water escaped from the lake, because these gases were heavier than the air and the concentration was high, they continued to converge over the villages in the valley, resulting in higher and higher concentrations of gases in the villages.
After people inhaled this high concentration of gas, not only a large amount of oxygen was lacking, but also poisoned, so in a short period of time, more than 1700 people and all livestock were killed.
Due to the huge agitation caused by the volcanic eruption, the lake water stirred a large amount of rhoderite at the bottom of the lake to the lake, so that Lake Nyos became a terrible reddish-brown color.
At this point, the reason for the killing of Lake Nyos was finally solved.
The disaster has attracted great attention to the Cameroonian government, in order to prevent the large number of harmful and toxic gases in Lake Nyos from being dehydrated again, the Cameroonian government decided to migrate and govern in parallel.
They first transferred the nearby residents, and then began the huge project of "exhaust and anti-spray".
The project was launched in 2001, and in 2009, scientists from the United States, France, Japan and other countries successfully used siphon devices to safely extract and release carbon dioxide gases and other toxic gases from Lake Nyos.
In April 2009, the team also developed an alarm that would alarm once the concentration of carbon dioxide and toxic gases in the lake water was too high.
To this day, Lake Nyos has not been a disaster of the past, but the Cameroonian government is still actively implementing prevention work and further studying Lake Nyos.