In front of the amazing nature, human beings look very small. The breathtaking Guilin landscape, the amazing Zhangjiajie, the colorful Jiuzhaigou, the mysterious and ancient Kunlun Mountains, the Bermuda Triangle with its own veil, they are beautiful, or dangerous, or have no life danger, even if the advanced science, still can not crack and unveil their mysterious veil.

Lake Nyos, located in northern Cameroon, Africa, is also one such presence. Lake Nyos looks beautiful and gentle, it is surrounded by granite rocks, lush meadows all around, and corn fields tilled by hard-working people.

The people there live by the water and rely on Lake Nyos to nurture generations of life. The surface of the lake has no ripples, the sun spilled on the lake water sparkling. But who would have thought that such a harmless appearance but has the title of "killer lake", has taken thousands of lives in one night!

From a distance, the fairy atmosphere floating, close look at the kill countless lives

Cameroon is a unitary republic located in west-central Africa, rich in geological resources and cultural diversity, with over 200 ethnic and linguistic groups living in the country, which is known as "Little Africa". This beautiful country is rich in different geological features, volcanoes and large lakes are also indispensable.

As one of the major lakes in Cameroon, Lake Nyos has always been a famous tourist mecca. It is a very beautiful lake, lying quietly on the slopes of the Pameta Plateau, with clear blue water, lush grasses, and a constant flow of birds and animals.

However, this is such a beautiful lake, both nurturing countless creatures around, but look closer but has a scary side. Lake Nyos is surrounded by a mountain range in Cameroon, which has an extinct volcano, and Lake Nyos is lying on the crater of this volcano. Therefore, this area of Lake Nyos is all volcanic area.

Although this volcano is always in a quiet state, but the hot springs all around it is a silent indication that this is a volcanic area, not only has the ability to breed life, but also has the ability to destroy everything.

Lake Nyos from afar, not only beautiful scenery, but also from time to time a little white smoke, like a curl of fairy gas, in conjunction with green mountains and water, birds and animals, just like a fairyland, so that a glance at the mood of lingering.

However, whenever you get closer and look closely, you can always see some animal carcasses. These corpses are either scattered at the foot of the mountain, or resting lakeside, no external injuries, the death is not gruesome.

Surrounding residents who did not think too much about why this is, the perennial comfort of life, and understand the natural world of the weak and the strong people did not take the death of a few animals to heart.

But is the extinct volcano next to Lake Nyos really as calm as it seems? The answer is no! This volcano that can be seen is indeed an extinct volcano, which has not shown signs of eruption for a long time.

However, there is a great potential danger under the low rock layer of Lake Nyos. It was an active volcano, constantly bringing the byproducts of volcanic activity - carbon dioxide - into the lake, which settled in a unique pattern of movement at the bottom of the lake and could not be emitted, and the high concentration of carbon dioxide allowed creatures close to the lake to die silently.

The murderous lake has a ferocious nature and kills thousands of people a night

The story goes back to the early morning of August 21, 1986, when people in a deep sleep were awakened by a loud explosion.

From the mouths of survivors, people know what terrible things this quiet village experienced on that terrible night, "I heard a violent sound like an atomic bomb explosion, was awakened by this loud noise, followed by a strong irritating smell, I felt weak, my hands and feet paralyzed and not at all obedient to my command, I had no way I was unable to make a sound, my surroundings became gradually blurred, and I fainted on my way to my child's room."

When the survivor woke up again around nine o'clock in the morning, "I was awake again because someone was knocking anxiously on my door, and they were knocking and calling my name. My friends poured into my home, talking about something I couldn't hear clearly, and I opened my mouth to speak, but I still couldn't find my voice.

They checked around and found that no one in the home was spared except me, and I was quickly moved, and as I left the home, I was surprised to find a very tragic surrounding with no survivors."

The incident caused the death of more than 1,700 people overnight, none of the birds, animals and livestock around Lake Nyos survived, people did not even have a chance to struggle to resist, and many even died in their sleep.

The Cameroonian government attaches great importance to this incident, not only sent its own researchers to the scene of the incident in Lake Nyos in time to investigate, but also invited international outstanding scientists to study the cause of the incident at the first time. George Ning, a professor from the University of Michigan, and Bill Evans, a scientist from the USGS, were the first to arrive at the "battlefield".

As the scientists explored the mystery, the hideous face of Lake Nyos gradually unfolded that night.

The violent roar should originate from the eruption of the active volcano at the bottom of Lake Nyos, the lake can no longer bear too much harmful gas, then Lake Nyos water began to erupt, forming a high-speed eruption of water column with a speed of up to 100 kilometers per hour, carbon dioxide gas overflowing water column, along the walls of the volcano flowing into the valley, that is the home of people in groups.

The water column carrying the overflowing carbon dioxide quickly formed a high-density air mass that enveloped people overhead, with a diameter of up to 23 kilometers and a cloud thickness of up to 50 meters.

The foul-smelling gas cloud of smoke thickened at 6 a.m., peaking between 8 and 10 a.m. At 11 p.m., the smoke began to show signs of dissipation.

During this period of time, all creatures in this space will react to carbon dioxide poisoning, because the concentration of carbon dioxide is so high that almost people in the lowlands have no chance of survival for a while, and there are only survivors among those who run hard to the top of the mountain when they find something different or those who already live in high places.

After the "fury" of Lake Nyos not only became turbid, but also showed a strange maroon color.

Strong government intervention, draining water to find the culprit

Because of this disaster, the Cameroonian government was determined to find the "killer" lurking at the bottom of Lake Nyos and bring him to justice to prevent such a disaster from happening again, and a team of experts, strongly supported by the government, conducted a long study in the Lake Nyos area.

By analyzing the state of the dead and survivors, the experts came up with the possibility that they were carbon dioxide poisoned, and then combined with the curling white smoke floating on Lake Nyos, the team led by George Ning and Bill Evans tested the lake water first and concluded that these white fumes were carbon dioxide.

Following the trail, the group found a surprising discovery at the bottom of Lake Nyos.

According to experts, "Lake Nyos is on a volcano with a carbon dioxide "spring" at the bottom of the lake that constantly delivers carbon dioxide to the water. The carbon dioxide that cannot overflow out of the water accumulates more and more, so Lake Nyos is like a time bomb, just waiting for an opportunity from outside to detonate this bomb, so that caused the tragedy."

And carbon dioxide accounted for ninety percent of the water of Lake Nyos, under the strong action of the outside world, all the carbon dioxide overflowed for a while, so that the living creatures in a hundred-mile radius have no chance to survive.

So what caused the lake to turn red-brown? Having uncovered a mystery, scientists again focused on the discoloration of the lake. After careful testing, the stratification of Lake Nyos that possesses stability was also revealed.

With a high concentration of carbonates at the bottom of the lake and a large amount of rhodonite in the water, together with carbon dioxide, the water of Lake Nyos is regularly layered according to different chemical compositions, maintaining a delicate chemical balance.

These chemical components that do not interfere with each other, but also because of the same in a lake and the great danger lurking.

On the day of the incident, an accidental landslide triggered the "switch", and a large number of sliding rocks tumbled into Lake Nyos, and the falling rocks caused a huge tumble in the lake. This external stirring force broke the long-standing delicate balance, which led to this "human tragedy".

And that day the bottom of Lake Nyos volcanic eruption stirred up the lake, which is another huge churning force while forcing the carbon dioxide out of the water, and the bottom of the lake diamond iron ore turned to the surface, so in the formation of the tragedy, but also the lake water into a bizarre maroon color, looks even more appalling.

Installation of alarm devices to avoid further tragedies

However, the "angry" Lake Nyos suddenly returned to calm, as if the overnight claim of more than a thousand lives had never happened, still quietly "alone beautiful".

However, the people did not let down their guard, and scientists did not stop looking at Lake Nyos, researching and searching for ways to manage it during this period.

Finally, in January 2001, scientists came up with a way to "detoxify" Lake Nyos by inserting a tube into the bottom of the lake and expelling the carbon dioxide from the lake when it didn't collect too much.

In March 2008, the government of Cameroon and the United Nations Development Programme signed a plan for the management of Lake Nyos and the resettlement of its inhabitants.

Plans indicate that this great project will be completed in 2010, when Lake Nyos will be completely and successfully treated and there will be no more tragedies like the one that occurred in 1986.

Cameroon hopes that with the scientists' bailout, similar tragedies will not recur, and as the government had hoped, the first phase of the Lake Nyos venting project has been successful.

In January 2009, the Lake Nyos treatment project had entered its second phase, and scientists could no longer be satisfied with just a few specially made tubes to extract carbon dioxide deep into the bottom of the lake. With the advancement of science, the use of siphons and the use of siphoning devices has become the best approach of the moment.

The siphon brings up a 50-meter-high column of water from Lake Nyos, taking out harmful gases from the water at a speed of 100 kilometers per hour, and the siphon is capable of extracting and releasing 20 million cubic meters of carbon dioxide per year. In addition, experts have installed an alarm system to warn about the concentration of carbon dioxide in the lake water.

More than twenty years have passed since the Lake Nyos incident, and the fear that nearly slaughtered four surrounding villages in one night has disappeared.

The average life expectancy in Cameroon is 60 years, even though the middle-aged people who still survived then are probably gone, only to be brought back home by their children to continue living in the land.

In early 2020, the global outbreak of the new crown epidemic did not spare this small, remote African country. On March 6, 2020 local time, Cameroon's Ministry of Health announced for the first time to the public the first case of New Crown pneumonia in Cameroon, which was a patient from France.

However, the disease that has countries around the world on alert, because it has started to spread in African countries making everyone more worried, has not caused alarm to the people around Lake Nyos.

Sanitary and medical conditions there are very low, located in the tropics, is a hotbed for the spread of many diseases and bacteria, itself Cameroon is endemic to malaria, cholera, AIDS, yellow fever ...... New Crown pneumonia is just another deadly epidemic.

Those who survived the disaster still grow corn on the land and enjoy the rich water resources brought to them by Lake Nyos.

In 2021, the epidemic in China enters a phase of dynamic clearing, but instead of controlling the global epidemic, the virus has become more active, and Cameroon is one of them.

"But Lake Nyos never went wild again, and we can still sprinkle seeds of corn here and quietly wait for them to germinate, ripen, and bear fruit."

Those survivors rejoice in the peace of Lake Nyos for more than two decades. The alarms installed by the scientists are also calm, which proves that the siphon device has been working consistently to keep the life of one side of the people safe, which is the greatest meaning that science brings to mankind, right?

There is no rigid working day, except for simple commercial sales, and most of the people with "official jobs" work in foreign factories.

Despite the rapid development of the epidemic, the children did not stop going to school, except during working hours, and the adults gathered from time to time to play soccer, sing and dance as if the raging epidemic had absolutely nothing to do with their lives.

Concluding remarks

Now, the area around Lake Nyos has come back to life, with residents returning one after another to rebuild their homes. They are survivors of the disaster, but now they no longer have to fear that they will be killed by the lake at any time.

Because, the siphon device can reduce the level of carbon dioxide in the lake water, there is also an early warning system to detect the concentration of carbon dioxide in the lake water at any time, once the concentration is too large, it will light up the warning light and alarm, people will have the opportunity to stay away from the scene of the disaster.

References

1. Horror killing lake took 1700 lives in one night (documentary) "Strange News" 2014-10-21

[2] The mysterious murderer who spits fog and kills people - Lake Nyos - Basic Science - Theory and Method of Natural Science; Life World, 2006.07 110

[3] Stone Island, Killing Lake - Basic Science - Geophysics; Nature Discovery, 2001.09 69_71