Deadly lakes may explode again

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Deadly lakes may explode again
Pipes to avert disaster are working, but not quickly enough.
Andreas von Bubnoff



The pipe installed in Lake Nyos is powered by natural levels of carbon dioxide: it creates a mini explosion in an attempt to ward off a larger one.
© George Kling

Researchers involved in a unusual project to prevent natural disasters in two African lakes say the first few years of the attempt have gone well, but have not yet made things safe.

The project aims to remove dangerous levels of carbon dioxide from the bottom of two lakes sitting over volcanic sites in Cameroon. One of these, Lake Nyos, exploded in 1986, suffocating more than 1,700 people in the surrounding area with a plume of carbon dioxide.

After the explosion, scientists realized that a landslide or some other event had caused water rich in carbon dioxide to rise from the safety of the deeps. As its pressure decreased, the rising water released the gas dissolved within it, in the same way that bubbles form in champagne once the bottle is opened. As a result, the water shot to the surface, suddenly releasing fatal amounts of carbon dioxide into the atmosphere.

Pipe dreams

To solve the problem, an international team decided to pipe out the carbon dioxide-rich water in a controlled way. The first pipe was installed in 2001 in Lake Nyos. Another pipe was deployed in 2003 in nearby Lake Monoun, which killed about 40 people when it exploded in 1984.
http://www.nature.com/news/2005/050926/full/050926-4.html