Roughly 72 cubic miles (300 cubic kilometers) of CO2 and 14 cubic miles (60 cubic km) of methane sit at the bottom of Lake Kivu, Katsev said, which is also laced with hydrogen sulfide gas from the ...

However, all it takes is one minor disruption, and the gas filling the killer lake could come streaming out into the air. Lake Kivu is one of only three killer lakes like it in the world.

“It is peaceful here, unlike over there,” said Exauce Shalako, a 20-year-old man from Goma who was lounging on the shore of Lake Kivu in Rwanda one afternoon this month. Mr.