Lake Ngozi (or Lake Ngosi) is the second largest
crater lake
Crater Lake ( Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The lake partly fill ...
in
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
.
It can be found near
Tukuyu
Tukuyu, known as Neu Langenburg during the German colonial rule, is a small hillside town that lies about south of the city of Mbeya, at an elevation of around in the highland Rungwe District of southern Tanzania, East Africa.
Tukuyu town has ...
, a small town in the highland
Rungwe
Rungwe is a District in Mbeya Region, Tanzania. It is bordered to the north by Mbeya Rural District, to the east by Iringa Region, to the southeast by Kyela District, to the southwest by Ileje District and to the west by Mbeya District.
Acco ...
District,
Mbeya Region
Mbeya Region (''Mkoa wa Mbeya'' in Swahili) is one of Tanzania's 31 administrative regions. The region covers an area of . The region is comparable in size to the combined land area of the nation state of Guinea Bissau. Mbeya Region is borde ...
, of southern
Tanzania
Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
in East
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
. It is part of the
Poroto Mountains
The Poroto Mountains are a mountain range in the Mbeya Region of Tanzania. They are located east of the city of Mbeya. The Poroto Mountains are a northwestward extension of the Kipengere Range, and part of the Southern Highlands. The Poroto moun ...
and the northern rim of the caldera is the highest point in the range. The caldera mostly composed from trachytic and phonolitic lavas. Ngozi is a Holocene caldera that generated the Kitulo pumice 12,000 years ago during a
Plinian eruption, most likely in the same eruption that generated the caldera. Other eruption deposits are the Ngozi Tuff (less than thousand years ago) and the Ituwa Surge
base surge deposits of uncertain age, but intermediary to the Kitulo pumice and Ngozi Tuff. The youngest activity generated a pyroclastic flow that flowed southwards for 10 km around 1450 CE. Some pyroclastic cones surround the volcano. The walls of the caldera are forested, with the exception of segments scoured by landslides and high cliffs that inhibit access to the water. The inner caldera is forested with ''
Maesa lanceolata
''Maesa lanceolata'', the false assegai, is a tree species that is widespread in the Afrotropics, including Madagascar. It occurs from the southern Arabian Peninsula, southwards to the Eastern Cape
The Eastern Cape is one of the provinces of ...
'', ''
Albizia gummifera
''Albizia gummifera'' is a species of legume in the family Fabaceae, native to sub-saharan Africa and Madagascar, and naturalized in
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the large ...
'' and ''
Hagenia abyssinica
''Hagenia'' is a monotypic genus of flowering plant with the sole species ''Hagenia abyssinica'', native to the high-elevation Afromontane regions of central and eastern Africa. It also has a disjunct distribution in the high mountains of East ...
'', far fewer tree species than neighbouring mountains consistent with the recent geological origin of the volcano. The caldera itself is not subjected to hydrothermal activity, but large subaqueous CO
2 emissions and local legends of the killing power of the lake indicate a danger of
limnic eruptions. The lake floor according to echosounding is flat and has no terraces.
The lake does not undergo large scale fluctuations in lake level, with only minor differences between the dry and rainy seasons. Air temperatures above the lake are around 18 °C with only minor seasonal variations.
Sporadically, the forests were occupied by Safwa hunters. Reports in 2013 stated that in the following year a geothermal project would commence in the vicinity of the volcano halfway between Ngozi and the town of
Mbeya
Mbeya is a city located in south west Tanzania, Africa. Mbeya's urban population is 620,000 according to the 2022 census. Mbeya is the capital of the surrounding rural Mbeya region (population, with Mbeya, totals approx. 2 million).
Mbeya is sit ...
.
Local Myths and Folk Tales
There are a number of local myths and folk tales which surround the volcanic lake, and the surrounding area.
The Nyakyusa People (ethnic group in this area of Southern Tanzania) say that a shaman called Lwembe was chased from his birth village (Ukwama in the Makete area) to the waters of Lake Ngozi after the people had become weary of the deceptive nature of his magic.
Once Lwembe became an inhabitant of the waters edge, the local tribe's cattle began to disappear. It is said that villagers started going missing too if they ventured too close to the waters. Nyakyusa elders dispelled the area by rolling a huge boulder which had been placed in the heart of a fire for three days into the water, while casting their own spells. Since that time, the evils spell on the Lake has not returned.
The most commonly heard myth and folk tale is that of a group of Colonial German soldiers who disposed of treasure into the waters of the lake. They put a spell on the Lake to protect the gold and hamper any other persons' efforts to reclaim it. Some variations of the myth suggest that this caused an emission of poisonous gasses (which we now know could be linked to 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 ...
), while others claim that there is a twelve headed snake that protects the treasure and comes out to the surface on sunny days. Whether there ever was a treasure remains a mystery.
References
{{DEFAULTSORT:Ngozi
Volcanic crater lakes
Geography of Mbeya Region
Lakes of Tanzania
Southern Highlands, Tanzania
Volcanoes of Tanzania