Lake Nyos killed 1,746 people in 1986 then scientists found more gas

Lake Nyos looks deceptively ordinary in photographs. It sits in a volcanic landscape in north-western Cameroon, surrounded by steep green slopes and farmland. Yet beneath its surface, an unusual geological process once allowed enormous quantities of carbon dioxide to accumulate in deep water.On 21 August 1986, that gas escaped suddenly. A dense cloud of carbon dioxide moved away from the lake and into nearby communities, where it displaced breathable air close to the ground. By the time the event was over, 1,746 people had died, along with more than 3,000 livestock. It became one of the most closely studied examples of a limnic eruption, a rare phenomenon in which dissolved gas erupts from lake water.Three decades later, Lake Nyos had become the centre of something very different: a long-running international effort to understand volcanic lakes and reduce the possibility of another deadly gas release.Lake Nyos showed why carbon dioxide remained a threat after 1986The precise nature of the 1986 disaster was not immediately settled. Scientists considered different explanations for the sudden release, including the possibility of a volcanic event. The idea that the lake itself had rel...