Lake Kivu, between Rwanda and the Democratic
Republic of Congo is unique in the world : its deep waters contain an enormous
quantity of dissolved gas (3/4 carbon dioxide, ¼ methane).
this highly stratified lake, is stable and benign. A powerful disturbance caused
by the volcanic activity of Nyiragongo, situated on the north shore of the lake,
could cause an upsurge of deep water charged with dissolved gas.
would release, either through localised and limited emanations or through a cataclysmic
explosion involving a large part of the lake, a large quantity of suffocating
gas which would threaten the safety of neighbouring populations.
that Lake Nyos, in Cameroon, was the site of a gas explosion in 1986 which caused
the death by suffocation of 1800 people in an area of 30 km around the lake. Lake
Kivu contains 1000 times more gas than Lake Nyos and there are millions of people
living under threat.
We decided to conduct a multidisciplinary study of
the physico-chemical properties of Lake Kivu with the aim of evaluating the risk
of gas explosion in various scenarios involving the activity of Nyiragongo (eruption
or sub-lacustrine magmatic intrusion, effusion of lava during a fissural eruption,
as occurred in January 2002).