Due to its depth, surrounding climate, and underlying seismic activity, the Lake has a buildup of carbon dioxide, methane and sulfur dioxide. Water in deep lakes in Temperate zones are mixed every year, when the lakes average temperature passes 4 degrees Celsius, the temperature at which water is most dense. Temperate lakes don't get gas buildup in their depths. Deep tropical lakes can get this build-up. And dissolved gas can build up for decades or centuries. When some event brings deep water saturated with gas to a level of the lake under less pressure the gas comes out of solution, like the gas in bottle of soda pop. This can trigger currents causing more mixing, and the discharge of the gas can become a runaway event.
- Halbwachs, et al. (2002-03-09). Investigations in Lake Kivu(East Central Africa) after the Nyiragongo Eruption of January 2002: Specific study of the impact of the sub-water lava inflow on the lake stability (pdf). Solidarities. Retrieved on 2008-08-17. mirror