Massive Carbon Dioxide Release Kills Thousands at Lake Nyos
Lake Nyos, a volcanic crater lake in northwestern Cameroon, had long accumulated dissolved carbon dioxide from underlying magma. On the evening of August 21, 1986, a limnic eruption triggered the sudden release of a massive cloud of CO2 gas. The denser-than-air cloud flowed down valleys, asphyxiating people and livestock in nearby villages. Approximately 1,746 people and 3,500 animals died within hours, primarily from oxygen deprivation. Survivors reported a smell of rotten eggs and a rumbling sound before the disaster struck. International teams later investigated the rare geological event.
Why it matters: The Lake Nyos disaster revealed the dangers of gas-charged lakes in volcanic regions and prompted global scientific monitoring programs. It led to engineering solutions like degassing pipes installed at Nyos and similar lakes to prevent future catastrophes.