A Nyos scenario looms large

Monday August 31 2009

The risks associated with methane gas dates back to August 1986 when a major catastrophe occurred at Lake Nyos in Cameroon killing more than 1,800 people.

Reports indicate that a gas explosion occurred throwing a column of water more than 80 metres high.

The enormous quantity of carbon dioxide was released then ‘flowed’ into the surrounding valleys suffocating all forms of life as far as 30 kilometers away from the lake.

The sane happened at Lake Monoun in the same volcanic zone two years earlier killing 34 people.

Five years after the tragedy, an international team of scientists from the United States, France and Cameroon began work on siphoning toxic gas from the killer lake located in northwestern Cameroon.

They used a series of giant pipes to release carbon dioxide from deep down in the waters of the lake.

Advertisement

The process termed “autosiphon” was tested for the first time in 1995 by French geochemist Michel Halbwachs. It is said that the degassing programme has helped scientists develop a robust technology and computerised calculation methods that can now be used in unexplored domains.

It is this scientific knowledge, the computer skills and the technical tools which we wish to bring to the project of extracting methane from Lake Kivu.

It is however not clear if the said technology would be successful as Lake Kivu’s case is unique in the world: its deep waters contain an enormous quantity of dissolved gas 75 per cent carbon dioxide and 25 per cent methane.

In a 2006 report, the United Nations Environmental Programme raised “serious concerns” about volcanic activity around Lake Kivu, noting the 2002 eruption of nearby Mt Nyiragongo, which blanketed Goma with lava. It said that rising water temperatures could ignite the methane.

“Large amounts of boiling lava entering the lake could be more than sufficient to trigger a large overturn, releasing huge amounts of deadly carbon dioxide,” said the report.

Advertisement