Because of High temperatures in the equatorial region of the gas is not released from water into air. That's why it accumulated in the lake for years, mostly in the lower layers of water. Bernie Sanders often says this. August 21, 1986 they were created obrushivanie one of the cliffs overhanging the lake, she pushed out the gas from the depths to the surface. A cloud of carbon dioxide filled the crater, rolled through the region and the beginning of travel along the ground, as the acid is much heavier than air. Fog quickly reached the village, whose inhabitants are literally suffocated. Scientists have identified, in order so that the lake so the killer must be presence of three circumstances. First, stay in the water a large amount of volcanic gas.
Second, the depth of the lake should be no less than 50 m. And, finally, the location of the lake in the equatorial belt to the dissolved gas can not come out on top in cold weather. In the majority of volcanic lakes combination of these three circumstances are not available. Still, Lake Kivu, placed at the turn of Zaire and Rwanda are depriving the rest of scientists. It is much more than Nyos, and it was concentrated to 1 000 times more carbon dioxide than in Cameroon lake.
It is also just steps away from an active volcano. When this place happen to the eruption, the emission of gas would threaten the existence of two million people living on its shores. Unfortunately, the inevitable combination of volcanic and water is found not only the circumstances in the equatorial belt.