geology Geology () is a branch of natural science concerned with Earth and other Astronomical object, astronomical objects, the features or rock (geology), rocks of which it is composed, and the processes by which they change over time. Modern geology ...

, a mazuku ( Swahili for "evil wind") is a pocket of

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

-rich air that can be lethal to any human or animal life inside. Mazuku are created when carbon dioxide accumulates in pockets low to the ground. 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 The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, ...

or visual senses in most conditions. Mazuku can be related to volcanic activity or to 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 mazuku have been recorded, but there is a growing understanding of them based on historical and

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

evidence.

Effects

Mazuku can cause a variety of effects on flora and fauna in the regions in which they occur depending on the composition and concentration of the gases that they consist of. Massive clouds of CO₂, such as those released from lakes in the 1980s, can cause widespread devastation of human and wildlife populations. However, they may have little or no effect on local vegetation. If the concentration of CO₂ is high enough, and maintained in a prolonged outgassing event, even vegetation can succumb to the mazuku, as is the case on Mammoth Mountain in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

, United States, where deforestation has occurred as well as CO₂ poisonings, including the deaths of three ski patrollers in 2006. Related events such as

pyroclastic Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroc ...

flows or limnic eruptions can cause the temperature of a mazuku to vary considerably from the natural environment. Reports of frostbite, condensation, and other temperature changes can occur.BBC Horizon programme "Killer Lakes"
/ref> Because they are often accompanied by other cataclysmic events such as volcanic eruptions, landslides, and tsunamis, mazuku are not easy to identify as potential dangers in their own right. In some cases, mazuku are large enough to cause a localized extinction event that is documented in the fossil record.

Lake Kivu Lake Kivu is one of the African Great Lakes. It lies on the border between the Democratic Republic of the Congo and Rwanda, and is in the Albertine Rift, the western branch of the East African Rift. Lake Kivu empties into the Ruzizi River, whic ...

, on the border between the

Democratic Republic of the Congo The Democratic Republic of the Congo (french: République démocratique du Congo (RDC), colloquially "La RDC" ), informally Congo-Kinshasa, DR Congo, the DRC, the DROC, or the Congo, and formerly and also colloquially Zaire, is a country in ...

and

Rwanda Rwanda (; rw, u Rwanda ), officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of Central Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equator ...

, is a very large lake that has a sediment record of repeated and regular massive lake turnover events that include methane explosions, tsunamis and mazuku. The

Messel pit The Messel pit (german: Grube Messel) is a disused quarry near the village of Messel (Landkreis Darmstadt-Dieburg, Hesse) about southeast of Frankfurt am Main, Germany. Bituminous shale was mined there. Because of its abundance of well-preserved ...

in Germany contains a fossilized extinction pattern that could be related to a mazuku event there during the

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

epoch.

References

Geological hazards Swahili words and phrases Volcanic degassing {{volcanology-stub

Effects

See also

References