Manoun lake

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Manoun lake
Lake Monoun.jpg
Geographical location Ouest Province , Cameroon
Drain Panke → Noun → Mbam
Data
Coordinates 5 ° 34 '45 "  N , 10 ° 35' 4"  E Coordinates: 5 ° 34 '45 "  N , 10 ° 35' 4"  E
Manoun Lake (Cameroon)
Manoun lake
Maximum depth 97 m

Lake Manoun , also known as Lac Monoun , is a lake in western Cameroon , in the French-speaking region of Ouest , around 20 kilometers as the crow flies east-northeast of its capital Bafoussam .

The lake is a Maar and belongs to Oku - volcanic field .

Gas leak

On August 15, 1984, large amounts of carbon dioxide (CO 2 ) suddenly escaped from the lake, causing 37 people to suffocate near the shore. Carbon dioxide is a gas that is heavier than air and therefore initially concentrates near the ground. The cause of this sudden release of gas initially puzzled science; people thought of a terrorist attack rather than a natural phenomenon.

Only through a similar tragedy at the Nyos crater lake, also located in the Oku area, was a plausible explanation found: A magma chamber below the area is the source of carbon dioxide, which rises through the lake floor. An estimated 90,000 tons of CO 2 dissolve in the water of Lake Nyos every year and lead to oversaturation with CO 2 . Since the lake water is thermally stratified (layers of warm, less dense water on the surface lie over cold, denser layers on the sea floor), the CO 2 does not escape immediately. Cold water can absorb much larger amounts of CO 2 than warm water. Large amounts of carbon dioxide are dissolved in the water of the lake over long periods of time.

Initially, the CO 2 remains dissolved in the lower layers, but at some point the water becomes oversaturated. When an event such as a landslide , a small earthquake or volcanic activity occurs, the cold and warm water layers mix, so that large amounts of CO 2 suddenly rise from the water. The process of sudden degassing can be compared to opening a carbonated mineral water bottle (after shaking it).

Degassing project

Since 2003 there has been a degassing project in which the water saturated with CO 2 gushes out of the lake in a fountain through a pipe reaching into the deep water layers. This controlled degassing is intended to prevent dangerous CO 2 oversaturation.

As part of the degassing project, a decrease in the oxygen concentration of the near-surface water layer was observed in the vicinity of the plant. The cause is assumed to be the entry of iron through the deep water carried up.

See also

Individual evidence

  1. ↑ "Панке" on the Soviet General Staff map (accessed from http://www.topomapper.com on September 9, 2012)
  2. ↑ a b c Preliminary report on the June 2012 field expedition to lakes Nyos and Monoun, Cameroon. (pdf) Japanese-Cameroonian SATREPS Project on Safety, Rehabilitation, and Development of the Lakes Nyos and Monoun areas in Northwest Cameroon., June 19, 2012, accessed on March 28, 2015 .

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