Potential for great source of Power or Cataclysmic disaster for the ages

Imagine wandering into a village and finding no living thing present for miles around. Animals all dead lying on the ground, from the grazing cattle to the buzzing fly with no living person in the vicinity. The source of death leaving no trace, or sign of bloodshed, nor any indication of a natural disaster.  Just a mound of lifeless bodies lying around, leaving you horrified and wondering what the hell happened. Such a terrible scene would qualify for horror movie material but this is exactly what happened in the villages around Lake Nyos in Cameroon where more than 1700 people instantly died from asphyxiation ( suffocation due to lack of oxygen ) from the huge quantities of carbon dioxide that had been emitted from the lakes.

 Such terrible natural disasters are so rare that only 2 have ever been recorded, once in 1984 from lake Monoun and another in 1986 in lake Nyos but now an even greater danger lies dormant. Lake Kivu much bigger, and situated in a more densely populated region could potentially be the source of a devastating calamity.

Lake Kivu is among 3 of the rare water bodies in the world that are known as limnic lakes . Lakes such as these have the property of erupting massive amounts of Co₂ a phenomenon known as a lake over turn. An event that could be triggered by various catalysts such as an eruption, or earth quake if the saturation of the Co₂ contained within the lake reaches critical levels of 100%. To Illustrate this in Layman terms, prior to a lake being saturated, it behaves like an unopened carbonated beverage (soft drink): the CO₂ is dissolved in the water similarly to how it is dissolved in the lake. In both the lake and the soft drink, CO₂ dissolves much more at a high pressure. When the drink is open, the pressure is released thus making the CO₂ come out of solution. If the lake reaches full saturation the pressure exerted by the gases will be more than the pressure caused by the lake thus making it highly unstable and a trigger is all that is required to set off an eruption sending vast amounts of Co2 to go bubbling out of the lake.

Fortunately the chances of such an event transpiring are not high. “The risks are a little bit above 50 percent given the saturation levels of the gas in the Lake.” Says Umutoni  Augusta, Engineer in charge of environmental concern in the Lake Kivu project. “The pressure exerted by the gas contained in the lake needs to be more than the hydrostatic pressure of the water.” She went on to say. This is something that is not likely to occur due to the recent methane gas extraction that is being undertaken right now.” CH₄ (methane ) has a big partial pressure , if you extract methane gas out you significantly reduce the overall pressure exerted by both gases “. The extraction of methane gas not only acts as source of vast amounts of energy but it also increases the stability of the lake.

“The lake produces more gas and recharges itself at a rate of 150 million cubic metres  per year , this would take about 100 years for it to reach critical saturation levels  of 100 % , presently we are still on 57 % level of saturation. “ She says, making the great danger seem not so imminent.

It should be noted however that Lake Kivu is situated in a region of high seismic, and volcanic activity, it is even close to the active volcano , Nyiragongo , which erupted in 2002. The eruption caused lava to cover a big portion of Goma even streaming down lake Kivu. At the time, this incident caused a lot of fear, that the lava might cause gas saturated waters to rise to the surface, however this did not happen. “After the explosion the European union sent an expedition of experts to investigate on this and it was discovered that the lava had sunk to a depth of around 100 meters beneath the lake , where as the main gradient of the gas is at level of 260 meters. This indicates that a seismic wave that would only be able to make lava reach at that point and trigger a lake overturn would have to be one of monumental magnitude.” Observed Augusta, something that is unlikely to occur.

Nonetheless this improbability should not be taken for granted, because there is another area of Lake Kivu , known as Kibuno Bay that has been discovered to contain 100% saturation levels of carbon dioxide. The discovery of this has prompted the establishment of a de-gasing plant in order to reduce the risks. However installation and implementation of this project is far from being underway.

Lake Kivu seems to be as fascinating as much as it is potentially hazardous, nevertheless It would be safe to assume that the dangers lying around lake Kivu despite their great disastrous potential have a low probability of occurrence. The methane gas project for now is an excellent way to reduce this danger in the long term by not only providing a great socio economic benefit but by also maintaining and perhaps increasing the stability of this great lake