Mysterious fog kills mass

In 1986, an unexpected misty fog covered a residential area near Lake Nyos in Cameroon that claimed the lives of nearly 2,000 people in one night. The story still hurts scientists until now.

'Lake of murder' and 10,000 mysterious deaths in the night

Animals die in the fog of Lake Nyos.

Terrifying dinner

On the night of August 21, 1986, a huge haze appeared above Lake Nyos in the remote mountains located in northwestern Cameroon. The heavy white mist slowly slid down the hills, into the valley and the surrounding villages and suffocated all the creatures along its path. As a result, 1,700 people were found to have mysteriously died in the morning. "There was no sign on their bodies to show that they were injured or had a clash that led to death, " said Anthony Bangsi, a missionary in Subum village.

Many people's bodies were burned and some survivors described that they had smelled sulfur gas that night. Anthony's father was one of the fortunate witnesses who survived the disaster that wiped out nearly the entire village. But Anthony's father, as well as any of the locals who were lucky to escape, could not explain what had happened. On that day, the news of the scale of the astonishing tragedy spread beyond the Cameroon border, leaving many people unable to be shocked and doubtful.

But this is not the first time this strange story has taken place. In 1984, there were 37 people living in Lake Monoun , 59 miles southeast of Lake Nyos, also mysteriously died. Like in the disaster at Lake Nyos, the victims died suddenly in the night without any sign of a collision before they died.

The original hypothesis

The American expert named George Kling was one of the first scientists to appear at the Nyos disaster scene after the event. He believed that there was a volcanic eruption beneath the lake and that it could be the cause of mysterious deaths. However, Kling could not find a trace of a hot lava flow, a fire fountain or anything that showed that volcanic gas was pumped into the air that night because sulfur gas was often accompanied. with lava eruptions. Furthermore, the lake's temperature indicates that they are actually cooler than normal, rather than being heated after an eruption.

Since then, Kling felt suspicious of his original hypothesis and thought that perhaps the volcano was not the cause of the deaths of nearly 2,000 people here. He began to redirect the investigation and turned to an earlier hypothesis of the Icelandic volcanic researcher Haraldur Sigurdsson , who had been to Cameroon investigating a similar tragedy two years ago at the lake. Monou led to the same mysterious death of 37 people living there. Sigurdsson also investigated to confirm whether volcanic activity was the cause of this tragedy and that his tests also showed that there was no evidence that the volcano had erupted lava. and hot air.

However, Sigurdsson found that in the lake water contains a large amount of CO2 , a natural gas that can kill people through the respiratory tract. Sigurdsson built a theory called " Subversion Lake " that claimed that the lake itself released a large amount of toxic gas that it accumulated into a murderous mist. But in fact, there has never been a case like this before that has been recorded, and in addition to the limitations of science at that time, Sigurdsson's hypothesis became too many loopholes and never been. known before that time.

Therefore, his contemporaries ignored that theory. When he proposed to check the CO2 concentration of other lakes in the region, the Government of Cameroon refused. And it was this mistake that led to great losses later on the lives of 2,000 people around Lake Nyos two years later.

Portrait of "murder" hidden face

Back in Nyos the next time, George Kling believed that Sigurdsson's theory was correct. He independently conducted water testing in Lake Nyos and found a large amount of CO2 in the deep waters of the lake. He said that it was this natural gas that rose into a toxic cloud and poisoned three lakeside villages. This cloud can be seen with the naked eye, they move very smoothly and without smell. These three elements combined make it a perfect killer. This hypothesis is also quite consistent with the burns detected on the victims' bodies. It is caused by cold CO2 rather than hot air from volcanoes.

Kling also cited research results from the US Air Force that exposure to large amounts of CO2 can lead to hallucinations that make them imagine that they smell sulfur. And it was from this theory that paved the way for modern scientists to expose the true face of the mysterious killer.

View of Lake Nyos.

Lake Nyos and Lake Monoun are all lakes lying on the crater. They are formed during the cooling of volcanoes and rainwater accumulation. In most of these lakes, the aquifers circulate from the bottom of the lake and vice versa in a cycle. In the process, gases from the ground penetrate into the bottom of the lake will eventually be released into the atmosphere. But Lake Nyos, Lake Monoun and even Lake Kivu in East Africa are not the same. The lake water layer has no rotation on the bottom and so, toxic gas when entering the bottom of the lake will be locked here.

When a storm or a landslide occurs, a strong seismic will cause a large amount of surface water to sink to the bottom and simultaneously push water from the bottom up. The toxic gas from the dissolved state will escape like bubbles rising from a bottle of water with the lid open.

According to calculations by scientists, during the Lake Nyos event in 1986, gas and water rose to a column of about 80m high, traveling at 45mph and spreading to villages 12 miles away. It is estimated that the lake released about 1km3 of CO2 enough to fill 10 football fields. In Lake Monoun, this cloud of gas is smaller, but it is enough to kill 37 people.

The amount of toxic gas in Lake Nyos and Monoun is now even greater than before the eruption in 1986, making people living around the area worrying. In early 2010, a group of American scientists began removing the detonator for Lake Nyos by placing a polyethylene tube deep in the bottom of the tank, causing the CO2 gas below it to foam and release CO2. into the atmosphere. Thus, the pressure at the bottom of the lake will decrease, lowering the risk of eruption. Dr. James G. Smith, a geologist at the International Development Agency, the project's main sponsor, said: "This will be the first time we can prevent a natural disaster." .

In addition to setting up a toxic gas elimination system, scientists also installed an early warning system on each tank. When CO2 levels rise, sirens and flashing lights will operate, alerting people living in the area to escape.

Even so, the danger is not over. According to scientists, Lake Nyos still contains huge amounts of CO2 and a single pipe is not enough to free them. It takes 4-5 similar pipes to eliminate the danger here as well as Lake Monoun.