Odd lakes

If you've heard me ramble on about the Aral Sea and how it's gotten so much smaller over the last 40 years, then you know something of how strange bodies of water can pique my interest. This morning, the BBC called my attention to Lake Nyos and Lake Monoun in Camaroon. These two lakes in the volcanic region in the northern part of Camaroon are two of three known lakes (the other is in Rwanda) that sit on top of magma chambers that vent carbon dioxide into the bottom of the deep lakes. The bottom layer of the lake become supersaturated with carbon dioxide, and then if something traumatic, like a small earthquake, happens to upset the delicate balance, there is a sudden overturning of the water and a giant cloud of carbon dioxde is released into the air. This is called a limnic eruption. This happened in 1984 at Lake Manoun, and it killed 37 people. Two years later, however, when Lake Nyos erupted, nearly 1800 people died. This tragedy lead to the Lake Nyos and Monoun Degassing Project at the University of Michigan. This morning's BBC report said that they think Lake Nyos may be ready for another eruption and their efforts to vent the lake with pipes from the bottom have not had a large enough effect.

Lake Nyos apparently has an additional problem. It's a crater lake on the side of a volcano, and one side of it is held back by a natural dam of volcanic rock which some scientists think may soon give way flooding the valley below.