Just Richter 5 or greater earthquakes in the last forty years. One
might think that most of these earthquakes are too far away and too
weak to disrupt Lake Kivu. There are three problems: (1) the lake is
already so saturated with methane and carbon dioxide that
comparatively very little movement would be needed to trigger an
overturn (2) earthquakes can trigger volcanic activity - the lake is
within easy lava range of Nyiragongo - as well as slope failures along
the western shores (3) As a Rift lake, Kivu is right on the Albertine
fault where Africa is relentlessly being torn apart. Earthquakes here
rarely follow a classical pattern.