Lake Monoun
Encyclopedia
Lake Monoun is a lake
in West Province, Cameroon, that lies in the Oku Volcanic Field
5.58°N 10.59°E. On August 15, 1984, the lake exploded in a limnic eruption
, which resulted in the release of a large amount of carbon dioxide
that killed 37 people. At first, the cause of the deaths was a mystery, and causes such as terrorism were suspected. Further investigation and a similar event two years later at Lake Nyos
led to the currently accepted explanation.
Although Lake Monoun is near the center of a volcanic field
that includes at least 34 recent craters, the subsequent investigation found that the event was not caused by an eruption or sudden ejection of volcanic gas from the lake. Rather, emission of carbon dioxide
in a limnic eruption
is thought to be to blame. The cloud's smell and skin damage to victims were not fully explained. Some theories attribute the skin problems to a combination of preexisting conditions and routine postmortem effects like livor mortis
, although there is no clear consensus.
Among the victims were some of the riders in a truck carrying twelve people. The truck's engine stopped working, and the people inside the truck got out and were killed. Two people sitting on top of the truck survived, however, because their elevated position allowed them to breathe - carbon dioxide is heavier than air (oxygen and nitrogen) which causes it to stay close to the ground.
Two years later, a similar and even more deadly event occurred at Lake Nyos
, about 100 km (62.1 mi) NNW. Along with Lake Nyos and Lake Kivu
, Lake Monoun is one of only three lakes in the world known to have high concentrations of gas dissolved deep below the surface.
it created buoyancy
in the water in the pipes, allowing the pump to be turned off.
However, a study in September 2005 by George Kling and other researchers at the University of Michigan
found that gas was not being removed from the lake quickly enough to ensure that the disaster never happens again. Kling recommended the lowering of the existing pipe and the addition of a new one in order to release more carbon dioxide.
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
in West Province, Cameroon, that lies in the Oku Volcanic Field
Oku Volcanic Field
The Oku Volcanic Field or Oku Massif is group of volcanoes based on a swell in the Cameroon Volcanic Line, located in the Oku region of the Western High Plateau of Cameroon.The Mount Oku stratovolcano rises to 3,011 m above sea level....
5.58°N 10.59°E. On August 15, 1984, the lake exploded in a limnic eruption
Limnic eruption
A limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which carbon dioxide suddenly erupts from deep lake water, suffocating wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists...
, which resulted in the release of a large amount of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
that killed 37 people. At first, the cause of the deaths was a mystery, and causes such as terrorism were suspected. Further investigation and a similar event two years later at Lake Nyos
Lake Nyos
Lake Nyos is a crater lake in the Northwest Region of Cameroon, located about northwest of Yaoundé. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity...
led to the currently accepted explanation.
Disaster
Several people reported hearing a loud noise on August 15, 1984 around 22:30. A gas cloud reportedly emanated from a crater in the eastern part of the lake. The resulting deaths of residents in a low-lying area are believed to have occurred between 03:00 and dawn. The victims were said to have skin burns, which reports later clarified as "skin damage" such as discoloration. Survivors reported that the whitish, smoke-like cloud smelled bitter and acidic. Vegetation was flattened around the eastern part of the lake, probably by a tsunami.Although Lake Monoun is near the center of a volcanic field
Volcanic field
A volcanic field is an area of the Earth's crust that is prone to localized volcanic activity. They usually contain 10 to 100 volcanoes, such as cinder cones and are usually in clusters. Lava flows may also occur...
that includes at least 34 recent craters, the subsequent investigation found that the event was not caused by an eruption or sudden ejection of volcanic gas from the lake. Rather, emission of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
in a limnic eruption
Limnic eruption
A limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which carbon dioxide suddenly erupts from deep lake water, suffocating wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists...
is thought to be to blame. The cloud's smell and skin damage to victims were not fully explained. Some theories attribute the skin problems to a combination of preexisting conditions and routine postmortem effects like livor mortis
Livor mortis
Livor mortis , postmortem lividity , or hypostasis is one of the signs of death...
, although there is no clear consensus.
Among the victims were some of the riders in a truck carrying twelve people. The truck's engine stopped working, and the people inside the truck got out and were killed. Two people sitting on top of the truck survived, however, because their elevated position allowed them to breathe - carbon dioxide is heavier than air (oxygen and nitrogen) which causes it to stay close to the ground.
Two years later, a similar and even more deadly event occurred at Lake Nyos
Lake Nyos
Lake Nyos is a crater lake in the Northwest Region of Cameroon, located about northwest of Yaoundé. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity...
, about 100 km (62.1 mi) NNW. Along with Lake Nyos and Lake Kivu
Lake Kivu
Lake Kivu is one of the African Great Lakes. It lies on the border between the Democratic Republic of the Congo and Rwanda, and is in the Albertine Rift, a part of the Great Rift Valley. Lake Kivu empties into the Ruzizi River, which flows southwards into Lake Tanganyika...
, Lake Monoun is one of only three lakes in the world known to have high concentrations of gas dissolved deep below the surface.
Degassing
In 2003, a venting pipe was inserted into the lake, in an effort to prevent the disaster from recurring. Initially a pump was needed to pull water from the bottom, but as carbon dioxide began to come out of solutionSolution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
it created buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...
in the water in the pipes, allowing the pump to be turned off.
However, a study in September 2005 by George Kling and other researchers at the University of Michigan
University of Michigan
The University of Michigan is a public research university located in Ann Arbor, Michigan in the United States. It is the state's oldest university and the flagship campus of the University of Michigan...
found that gas was not being removed from the lake quickly enough to ensure that the disaster never happens again. Kling recommended the lowering of the existing pipe and the addition of a new one in order to release more carbon dioxide.
See also
- Limnic eruptionLimnic eruptionA limnic eruption, also referred to as a lake overturn, is a rare type of natural disaster in which carbon dioxide suddenly erupts from deep lake water, suffocating wildlife, livestock and humans. Such an eruption may also cause tsunamis in the lake as the rising CO2 displaces water. Scientists...
- MazukuMazukuIn geology, a mazuku is a pocket of oxygen-poor air that can be lethal to any human or animal life inside. Mazuku are created when an odorless and invisible gas such as carbon dioxide accumulates in pockets low to the ground...
- Meromictic lake
- Lake NyosLake NyosLake Nyos is a crater lake in the Northwest Region of Cameroon, located about northwest of Yaoundé. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity...
- Lake KivuLake KivuLake Kivu is one of the African Great Lakes. It lies on the border between the Democratic Republic of the Congo and Rwanda, and is in the Albertine Rift, a part of the Great Rift Valley. Lake Kivu empties into the Ruzizi River, which flows southwards into Lake Tanganyika...
- Disasters
External links
- The Lake Nyos and Monoun Degassing Project
- Killer lakes in Cameroon may strike again
- Volcanic Lakes and Gas Releases -- Reports from the investigation of the disaster
- BBC News 27 Sep 2005: Action needed on deadly lakes
- Mechanics of the switching on of the trigger mechanism of limnological catastrophes - LatviaLatviaLatvia , officially the Republic of Latvia , is a country in the Baltic region of Northern Europe. It is bordered to the north by Estonia , to the south by Lithuania , to the east by the Russian Federation , to the southeast by Belarus and shares maritime borders to the west with Sweden...
n research by Nataliya Anatolievna Solodovnik and Anatoliy Borisovich Solodovnik