LAKE KIVU (Congo): The blue-green waters of Congo’s Lake Kivu conceal a deadly invisible mixture that could trigger a fiery disaster or be a blessing in disguise for the two million people who live around its shores.

Dissolved into the cold bottom waters of the lake, which straddles a part of Democratic Republic of Congo’s eastern border with Rwanda, are huge amounts of highly combustible methane gas and five times as much more carbon dioxide.

Lake Kivu lies just 15km from the active Nyiragongo volcano. If forced out by volcanic activity, the methane in the waters would ignite, causing massive explosions above the surface of the lake, experts say.

At the same time, a vast cloud of carbon dioxide would drift over surrounding land, smothering all life in its path and engulfing the nearby city of Goma.

“If there’s ever a volcanic eruption at the level of Lake Kivu, or if there’s an eruption that starts naturally in the city of Goma and spills a large quantity of lava into the lake ... the two gasses could find a way out,” Mathieu Yalire of Goma’s Volcanological Observatory said.

“That would be the beginning of a regional catastrophe.” Researchers recall the 1986 disaster at Cameroon’s volcanic Lake Nyos, when a lethal gas cloud erupted out of its waters and killed more than 1,700 people. Similar “killer lake” gas clouds have occurred at another lake in Cameroon and also in Indonesia.

If the same were to occur in Lake Kivu, scientists say the surrounding population of around two million people would be at risk.

Although experts view this as a “worst case” scenario, they say the possibility of such an event is growing.

In 2002, an eruption of the Nyiragongo volcano sent a river of lava through the centre of Goma, the capital of North Kivu province, spilling molten rock into the lake.—Reuters