Shulou(Shulou.com)11/24 Report--

(photo: Steemkr) on August 29, 2022, the color and smell of Lake Cook in northwestern Cameroon suddenly changed, causing anxiety and panic among local residents. Why does the change in the taste of the lake cause panic?

The story begins on the night of August 21, 1986, when a tragic natural disaster occurred in Cameroon.

Lake Wikipedia is a volcanic lake, 2km long and 1.2km wide. The lake is located at 1091 meters above sea level. At that time, Lake Nyos (Lake Nyos) in northwest Cameroon exploded and erupted at a speed of 100km per hour. High-density clouds filled with high concentrations of methane and carbon dioxide quickly enveloped all around, reaching a height of more than 120m and forming deadly clouds about 50m thick. The shrouded radius is more than 23 kilometers.

The explosion in Lake Nios caused asphyxiation of surrounding cattle. Source: Courtesy of J.P. Lockwood, USGS. Because the lake explosion occurred so suddenly, people in the surrounding villages were fast asleep, and in a short period of time, many people suffocated in bed.

Location of Lake Nios: a local survivor in conversation said in an interview: "I smelled a terrible smell in my sleep, but when I woke up I couldn't speak. I heard a terrible, abnormal sound coming from my daughter's mouth. I tried to go to my daughter's bed, but then I fell and fell to the ground. I fell to the ground until 9 am when I heard a sharp knock on the door. I tried to get up and open the door. I saw some of my friends. I wanted to talk, but I couldn't help it. I could hardly breathe. Then I found out that my daughter was dead. My neighbors are dead, too, and I saw almost no signs of life when I left Lake Nios. "

According to statistics, the deadly gas emitted by the lake explosion killed more than 1700 people, and thousands of cattle, sheep, birds and other animals were killed and injured. The village of Gamneo, near Lake Nios, was hardest hit, with only six of the village's 650 residents surviving.

Gas released from Lake Nyos on August 1, 1986 led to the death of surrounding livestock source: Eric Bouvet Why did Lake Nios suddenly explode and release so much carbon dioxide?

After the bizarre large-scale death in Lake Nios, the Cameroonian government sent its own scientists to investigate, but also invited international leading scientists to solve the mystery.

Deep lake water sampling source: jst.go.jp found that there has been carbon dioxide stored in the lake bottom and mantle for hundreds of years after investigation by scientists. These gases come from magma deep underground, and most of them are "pressed" and cannot be released underwater because of the pressure of the lake.

A small portion of the gas will be released, and it is estimated that about 5000 tons of carbon dioxide is released from the bottom of the lake each year, which is not fatal because of its slow release. But why did Lake Nios in Cameroon suddenly erupt and cause disaster when there are so many volcanic lakes in the world?

Carbon dioxide gas from the lake kills livestock: google site caused landslides after several days of rain around Lake Nios before the lake exploded. This broke the pressure balance of the lake water, causing the lake water that released 1.24 million tons of carbon dioxide to be pushed from the bottom to the surface by external forces, resulting in a tragedy.

In order to avoid tragedy, in January 2001, the Government of Cameroon successfully installed an exhaust pipe in Lake Nios to remove carbon dioxide and other harmful gases from the bottom of the lake, avoiding a large amount of gas storage and reducing the possibility of sudden explosion release.

In 2001, the lake was equipped with exhaust pipes. Source: wikicommons

Gas can be ejected from the pipe to form a fountain source: jst.go.jp, by comparing the image below, you will find that the exhaust pipe was much lower in 2013 than the jet of water that was just installed in 2001. It can be seen that the role of the exhaust pipe is still very obvious.

Photo Source: Lyell Collection in addition, the local government has installed carbon dioxide detectors around the lake. when the detectors detect high concentrations of gas, they will sound an alarm, asking the surrounding residents to flee and run to high places.

Carbon dioxide detector source near the volcanic lake: Atlas Obscura, but the danger of another explosion in the volcanic lake has not been completely eliminated. As mentioned earlier, the volcanic lake is still releasing gas, and the residents around the lake smell the rotten egg smell of hydrogen sulfide and see the color change of the lake, so they panic.

Although human beings can not completely overcome natural disasters, there is reason to believe that science can still reduce the probability of tragedies.

This article is from the official Wechat account: bring Science Home (ID:steamforkids). By Su Chengyu.

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