Mazuku
Pocket of carbon dioxide–rich air that can be lethal / From Wikipedia, the free encyclopedia
In geology, a mazuku (Swahili for "evil wind") is a pocket of carbon dioxide-rich air that can be lethal to any human or animal life inside.[1] Mazuku is created when carbon dioxide accumulates in pockets low to the ground.[2] CO2 is denser than air, which causes it to flow downhill, hugging the ground like a low fog, and is also undetectable by human olfactory or visual senses in most conditions.
Mazukus can be related to volcanic activity or a natural disaster known as a limnic eruption. In the first case, noxious gases are released from the Earth's crust into the atmosphere, whereas in the second case, the gases originate deep in a lake and boil rapidly to the surface. Because of their nature as sporadic and subtle events, few mazukus have been recorded, but there is a growing understanding of them based on historical and fossil evidence.