Disaster Of Lake Nyos
- The Adroit
- Jan 26, 2019
- 2 min read
21st august of 1986 ,a limnic eruption took place occurred at Lake Nyos which claimed life of 1746 living within 25 kilometers and as well as 3500 livestock.
Lake Nyos is a crater lake in northwest region of Cameroon. Lake Nyos is a deep lake lying on inactive volcano in the Oku volcanic plain. It is a meromictic , crater lake. It is 2 kilometers in length , 1.2 kilometers in width and has a surface area of 1.58 square kilometer.
Lake Nyos in one of the only three lakes( Lake Monoun and Lake Kivu) in the world known to be saturated with carbon dioxide. Lake Nyos contains a built up of carbon dioxide gas which is mainly due to gases erupting due to volcanic activity. Carbon dioxide stays at the bottom part of the lake due to high pressure .Due to high amounts of carbon dioxide built up in the lake it makes the lake very rocky . Usually the eruption of gases do not happen. But during disasters the lakes unstable nature amplifies and results in an explosion.
In 1986 , a landslide is considered to be the reason to trigger the explosion, making a situation analogous to this –
The explosion was so strong that it created a Tsunami of approximately 25 meter that inundated the surrounding area. A huge gas cloud consisting of carbon dioxide was released in the surrounding . As we know carbon dioxide is denser gas and do not diffuse quickly, so it pushed the breathable air upwards and created a toxic environment. People trapped in this incident died of suffocation. Impact of this explosion was felt up to 25 kilometers away from lake. Many people also suffered long term effects of exposure to the toxic environment. Around 1700 people and 3500 livestock lost their life that day.
The scale of the 1986 disaster led to much study on how a recurrence could be prevented. Estimates of the rate of carbon dioxide entering the lake suggested that outgassings could occur every 10–30 years, though a recent study shows that release of water from the lake, caused by erosion of the natural barrier that keeps in the lake's water, could in turn reduce pressure on the lake's carbon dioxide and cause a gas escape much sooner.
Several researchers independently proposed the installation of degassing columns from rafts in the lake. The principle is simple: A pump lifts water from the bottom of the lake, heavily saturated with CO2, until the loss of pressure begins releasing the gas from the diphasic fluid, thus making the process self-powered. In 1992 at Monoun, and in 1995 at Nyos, a French team directed by Michel Halbwachs demonstrated the feasibility of this approach. In 2001, the U.S. Office Of Foreign Disaster Assistance funded a permanent installation at Nyos.
In 2011, two additional pipes were installed by Michel Halbwachs and his French-Cameroonian team to assure the complete degassing of Lake Nyos.
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