Deadly Gas, Cheap Power

Lake Nyos: In 1986, gas released from Lake Nyos in Cameroon killed more than 1,700 people and thousands of animals.  corbis/scanpix

Africa’s Other Killer Lakes

Researchers know of three lakes in the world with the geological structure that make them capable of trapping and releasing deadly amounts of gas. All three lakes are in Africa, and in the past 25 years, two of them have demonstrated just how dangerous they are. The disasters at Lake Nyos and Lake Monoun in the 1980s were the first indications to scientists that the phenomenon was even possible. Pumps have been installed in both lakes to pull gas from their depths.

Lake Nyos is located in northwestern Cameroon. Under its waters lies a pocket of volcanic magma, out of which CO₂ seeps and dissolves into the lake’s water. On August 21, 1986, something—most likely a landslide, but possibly an earthquake or thunderstorm—triggered the release of a large amount of CO₂ from the lake. The gas spread up to 15 miles from the lake in a thick, suffocating cloud. Some people managed to escape, but 1,746 died, and thousands of animals were killed by a lack of oxygen. On the advice of scientists,
a pumping system was installed in the lake in 2001.
Lake Monoun is near Lake Nyos in Cameroon. On the night of August 15, 1984, people living near the lake heard a strange boom. It came from the lake, which released a CO₂ cloud that spread out and suffocated 37 people, including 10 people in a truck (according to published reports, two people sitting on the truck’s roof, above the CO₂ cloud, survived). What triggered the disturbance is still unknown. Pumps were installed in 2003 to avert a repeat disaster.