Lake Nyos in Cameroon is the most deadly lake in the world. Lake Nyos is a crater lake in the Northwest Region of Cameroon, located about 200 miles (322 km) northwest of Yaoundé.Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity. A natural dam of volcanic rock hems in the lake waters.
A pocket of magma lies beneath the lake and leaks carbon dioxide (CO2) into the water, changing it into carbonic acid. Nyos is one of only three known lakes to be saturated with carbon dioxide in this way, the others being Lake Monoun, 100 km (62 mi) away SSE, andLake Kivu in Rwanda. On August 21, 1986, possibly triggered by a landslide, Lake Nyos suddenly emitted a large cloud of CO2, which suffocated 1,700 people and 3,500 livestock in nearby villages. Though not completely unprecedented, it was the first known large-scale asphyxiation caused by a natural event. To prevent a repetition, a degassing tube that syphons water from the bottom layers of water to the top allowing the carbon dioxide to leak in safe quantities was installed in 2001, though additional tubes are needed to make the lake safe.
