In
geology
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Ear ...
, 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 trans ...
-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.
CO
2 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.
Mazuku can be related to volcanic activity or to a natural disaster known as a
limnic eruption
A limnic eruption, also known as a lake overturn, is a very rare type of natural disaster in which dissolved carbon dioxide () suddenly erupts from deep lake waters, forming a gas cloud capable of suffocating wildlife, livestock, and humans. A lim ...
. 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
![Cow killed by Lake Nyos gasses](https://upload.wikimedia.org/wikipedia/commons/c/c2/Cow_killed_by_Lake_Nyos_gasses.jpg)
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 CO
2, 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 CO
2 is high enough, and maintained in a prolonged outgassing event, even vegetation can succumb to the mazuku, as is the case on
Mammoth Mountain
Mammoth Mountain is a lava dome complex partially located within the town of Mammoth Lakes, California, in the Inyo National Forest of Madera and Mono Counties. It is home to a large ski area primarily on the Mono County side.
Mammoth Mount ...
in
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
, United States, where deforestation has occurred as well as CO
2 poisonings, including the deaths of three ski patrollers in 2006.
Related events such as
pyroclastic flows or
limnic eruption
A limnic eruption, also known as a lake overturn, is a very rare type of natural disaster in which dissolved carbon dioxide () suddenly erupts from deep lake waters, forming a gas cloud capable of suffocating wildlife, livestock, and humans. A lim ...
s 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"](_blank)
/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, 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.
See also
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References
Geological hazards
Swahili words and phrases
Volcanic degassing
{{volcanology-stub