- Date:
- August 21, 1986
Lake Nyos disaster
-
What is the Lake Nyos disaster?
On August 21, 1986, a limnic eruption at Lake Nyos in Cameroon caused a massive release of magmatic carbon dioxide gas, killing between 1,700 and 1,800 people.
The cloud of gas, which may have been triggered by a landslide or volcanic activity, asphyxiated people and animals within a 15-mile radius. The gas had built up in the lake due to a lack of seasonal mixing, which is common in other volcanic lakes. The disaster prompted research into preventing future limnic eruptions through controlled degassing and early warning systems.
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Where is Lake Nyos located?
On August 21, 1986, a limnic eruption at Lake Nyos, a freshwater lake in a volcanic caldera in Cameroon's Northwest Region, released a massive cloud of magmatic carbon dioxide. This rare disaster killed between 1,700 and 1,800 people, who were asphyxiated by the gas. It is theorized that the carbon dioxide, which had been seeping into the lake for centuries, was released by a disturbance such as a landslide.
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What happened at Lake Nyos in 1986?
On August 21, 1986, Lake Nyos in Cameroon experienced a limnic eruption, a rare event where a massive amount of carbon dioxide was released from the lake. This release asphyxiated approximately 1,746 people and 3,000 cattle, along with birds, insects, and other animals, within a 15-mile radius.
The carbon dioxide cloud, estimated to be about 0.3 cubic miles in volume, likely formed within minutes, with the gas possibly triggered by a landslide, volcanic activity, or an earthquake. Research teams later found that carbon dioxide had built up under high pressure in the lake's depths. Following the disaster, scientists implemented measures for controlled degassing and warning systems to prevent future explosions.
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What caused the sudden disaster at Lake Nyos?
On August 21, 1986, a limnic eruption at Lake Nyos in Cameroon caused a sudden disaster killed 1,746 people. The disaster was triggered by a massive release of magmatic carbon dioxide gas from the lakebed of this freshwater lake, which sits in a volcanic caldera.
The carbon dioxide had accumulated in the lake's depths due to a lack of seasonal mixing, a common occurrence in other volcanic lakes. A landslide, volcanic activity, or a minor earthquake may have triggered the release of the gas, resulting in a cloud with a volume of up to 0.3 cubic miles (1.2 cubic kilometers). This cloud spread over a 15-mile radius, asphyxiating people, animals, and vegetation.
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How did the Lake Nyos disaster affect people and animals nearby?
In 1986, a limnic eruption at Lake Nyos in Cameroon released a massive cloud of carbon dioxide that asphyxiated people and animals within a 15-mile radius. The deadly cloud resulted in the deaths of an estimated 1,746 people and 3,000 cattle, along with innumerable birds, insects and other animals. The victims showed no signs of trauma, indicating they were simply asphyxiated where they were. The eruption also caused a tsunami-like wave that flattened vegetation.
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What steps have been taken to prevent a similar disaster at Lake Nyos?
After the Lake Nyos disaster in 1986, which killed approximately 1,746 people, international scientific research was conducted to prevent similar occurrences. Steps taken include controlled degassing and the development of effective warning systems that allow for evacuation before an explosion occurs. Following initial degassing, fish were reintroduced to Lake Nyos in 1996. Further degassing has taken place at Lake Monoun and Lake Nyos, and no significant events have occurred at either since the explosions of the 1980s.
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Lake Nyos disaster, massive release of carbon dioxide from Lake Nyos in Cameroon on August 21, 1986. The disaster killed between 1,700 and 1,800 people.
On August 21, 1986, a cloud of magmatic carbon dioxide gas arose from the bed of Lake Nyos, a freshwater lake located in a volcanic caldera in the populous Northwest Region of the East African nation of Cameroon. The rare event, called a limnic eruption, was announced by a small explosion that residents of a market town near the lake described as being like distant thunder, but it was otherwise unannounced by anything else apart from a foul odor.
The 1.6-million-ton cloud of magmatic gas was deadly, and a count of the fatalities indicated that 1,746 people, most from villages by the lake, had been asphyxiated by it, along with some 3,000 cattle and innumerable birds, insects, and other animals. The bodies of the dead showed no signs of trauma or struggle; these people had simply died where they were. A research team from France and the United States arrived at the scene and noted that the lake was an unusual dark-brown color, and that a surrounding raffia forest and several other expanses of vegetation had been flattened by both the explosion and the tsunami-like water wave that ensued. That the lake was responsible for the deaths was immediately clear to the scientists, but the mechanism involved was not.
Further research found that carbon dioxide had built up under high pressure in Lake Nyos, as it had two years earlier at another Cameroonian volcanic lake about 60 miles to the southeast, Lake Monoun, killing 37 people. A landslide into the lake may have caused the gas to be released from the cooler depths of the lake; a volcanic eruption under the lake or even a minor earthquake might also have been the cause. The result was that the carbon dioxide burst out of the lake and into the air, poisoning those in its path and then dispersing. The usual level of carbon dioxide in the air is much less than a tenth of 1 percent, but near Lake Nyos levels may have reached 10 percent.
The incidents at both Lake Monoun and Lake Nyos prompted international scientific research to arrive at ways to guard against limnic explosions by, for instance, controlled degassing, and how to develop effective warning systems so that people might evacuate an affected area before an explosion occurs.
Some scientists view Lake Nyos as a modern exemplar of an ancient process, positing that massive eruptions of gases such as carbon dioxide and methane and the resultant lowering of oxygen levels triggered the mass extinction of animals such as the trilobites and terrestrial plants during the late Permian period, about 250 million years ago.
Following initial degassing, fish were reintroduced to Lake Nyos in 1996. Further degassing has taken place at Lake Monoun and Lake Nyos, and no significant events have occurred at either since the explosions of the 1980s.
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