Lake Nyos, Cameroon

In 1986, 1,700 people in West African Cameroon, suffocated when a giant bubble of naturally occurring carbon dioxide erupted from Lake Nyos and displaced the available oxygen in the immediate area. 

Lockwood JP, Rubin M (1989) Origin and age of the Lake Nyos maar, Cameroon. J Volcanol Geotherm Res 39 117-124 Lopez-Archilla AI, Marin I, Amils R (2001) Microbial community composition and ecology of an acidic aquatic environment the Tinto River, Spain. Microb Ecol 41 20-35... 

On August 15, 1984, a cloud of deadly gas burst from Lake Monoun in Cameroon, a country in western Africa. Thirty-seven people died from suffocation. Two years later, on August 21, 1986, Lake Nyos, a larger and deeper lake, ejected a full cubic kilometre of the same gas. The gas travelled silently into neighbouring villages, killing 1700 people and thousands of livestock. What was this toxic gas ... 

An important example of the consequences of a large C02 release occurred in 1986. Lake Nyos is a crater lake in Cameroon in west central Africa. In 1986, this lake belched a large cloud of carbon dioxide that settle in the region around the lake. More than 1500 people and 3000 head of livestock were killed in the C02 blanket. 

Another interesting result of carbon dioxide solubility in water is that it constitutes the basis for the phenomenon of spontaneous and violent liberation of dissolved C02 to the atmosphere in a stratified lake, as in the case of Lake Nyos in Cameroon mentioned above (see Section 6.1.3). When dissolved C02 seeps from a hydrothermal vent into a stratified lake, the pressure and low temperature favor the dissolution and saturation in the lower strata of the lake. Because of its high solubility, more than five volumes of C02 can dissolve in one volume of water. As for any other gas, however, its solubility depends on temperature and pressure, making the... 

Since 1986 the scientists studying Lake Nyos and nearby Lake Monoun have observed a rapid recharging of the C02 levels in the deep waters of these lakes, causing concern that another deadly gas release could occur at any time. Apparently the only way to prevent such a disaster is to pump away the C02-charged deep water in the two lakes. Scientists at a conference to study this problem in 1994 recommended such a solution, but it has not yet been funded by Cameroon. ... 

Freeth SJ, Kling GW, Kusakabe M, et al. (1990) Conclusions from the lake Nyos disaster. Nature 348 201. Kling GW, Evans WC, Tuttle ML, and Tanyileke G (1994) Degassing of lake Nyos. Nature 368 405—406. Sigurdsson HS (1988) Gas bursts from Cameroon crater lakes A new natural hazard. Disasters 12 131-146. 

Evans, W.C., Kling, G.W., Tuttle, M.L., Tanyileke, G. White, L.D. (1993) Gas buildup in Lake Nyos, Cameroon the recharge process and its consequences. 

Schenker, F., and Dietrich, V. J. (1986) The Lake Nyos gas catastrophe (Cameroon) a magmatological interpretation, Schweiz. Mineral. 

Disaster struck swiftly and without warning. On August 21, 1986, Lake Nyos in Cameroon, a small nation on the west coast of Africa, suddenly belched a dense cloud of carbon dioxide. Speeding down a river valley, the cloud asphyxiated over 1700 people and many livestock. 

Rudolph J, Rath HK, Sonntag C (1984) Noble gases and stable isotopes in " C-dated palaeowaters from central Europa and the Sahara. In Isotope Hydrology 1983 (IAEA-SM-270). IAEA, Vienna, p 467-477 Sano Y, Kusakabe M, Hirabayashi J, Nojiri Y, Shinohara H, Njine T, Tanyileke G (1990) Helinm and carbon fluxes in Lake Nyos, Cameroon Constraint on next gas burst. Earth Planet Sci Lett 99 303-314 Sano Y, Wakita H (1987) Helium isotope evidence for magmatic gases in Lake Nyos, Cameroon. Geophys Res Lett 14 1039-1041... 

The Pamukkale cavern wasn t the only place where carbon dioxide wreaked havoc with human lives. On August 21,1986, a terrible natural-chemical accident occurred in Cameroon, Africa. Within hours, thousands of animals and people had died in the area around Lake Nyos. It was as if some celestial plague had struck people dead in their tracks, but the dead showed no outward signs of disease. The culprit turned out to be carbon dioxide gas — the gas that bubbles from our soft drinks and that we exhale after every intake of breath. Where did it come from The bottom of the lake. 

Given that rock strata have held CO2 and methane for millions of years, there seems no reason that carefully chosen ones cannot hold sequestered CO2. However, the eruption of a million tons of CO2 from Lake Nyos in Cameroon in 1986 asphyxiated 1700 people, so the consequences of major releases of heavier-than-air gas are potentially serious. 

Lakes also exhibit thermal stratification. In the summer months a warm upper layer called the epilimnion is separated by a thermocline from a cool bottom zone or hy-polimnion. Autumn cooling of the epilimnion may make the surface water denser than the bottom water, provoking a turnover and bringing chemical species from bottom sediments to the top. Such recirculation can have severe biological consequences rapid tnmover of Lake Nyos in Cameroon brought so much water supersaturated with CO2 to the surface that a CO2 cloud formed and suffocated many area residents. 

The box text applies Henry s law to a natural disaster that occurred at Lake Nyos in Cameroon (west Africa). 

On August 21,1986, a cloud of gas suddenly boiled from Lake Nyos in Cameroon, killing nearly 2000 people. Although at first it was speculated that the gas was hydrogen sulfide, it now seems clear it was carbon dioxide. What would cause Lake Nyos to emit this huge, suffocating cloud of CO2 Although the answer may never be... 

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