Cameroon: 'An Invisible Avalanche' - What Happened in Cameroon's 1986 Lake Nyos Disaster?

What the report says

RFI, in a piece distributed by AllAfrica, revisits the 1986 Lake Nyos disaster in north-west Cameroon, where a sudden release of carbon dioxide killed 1,746 people and about 3,500 animals. The article says the gas escaped overnight from the lake’s deep volcanic waters, after a disturbance likely linked to a minor earthquake, and spread through nearby valleys as a dense cloud that displaced oxygen and caused victims to lose consciousness almost immediately.

The report describes how residents in Nyos and surrounding villages such as Subum and Cha were struck while asleep, leaving survivors to wake the next day to scenes of widespread death. It frames the event as the deadliest known limnic eruption, a rare natural disaster in which dissolved gas builds up in a lake and is suddenly released.

RFI says the tragedy has had lasting scientific significance. Since the disaster, researchers have worked to understand how carbon dioxide accumulated in Lake Nyos and similar lakes. The article notes that the lake remains under monitoring, though the danger has been reduced through artificial degassing. A first degassing pipe was installed in 2001, and measurements since then indicate lower carbon dioxide levels.

The story also places Nyos in a broader regional context, noting that studies there have helped scientists assess other gas-rich volcanic lakes, including Lake Monoun in Cameroon and Lake Kivu on the Democratic Republic of the Congo-Rwanda border.