Lake Natron
Location:
Lake Natron is situated in the Arusha Region of northern Tanzania, close to the Kenya border, within the East African Rift Valley system.
Geographical and geological setting
Located in the Arusha Region, northern Tanzania.
Part of the East African Rift System.
Influenced by nearby Ol Doinyo Lengai, an active carbonatite volcano.
Formed due to tectonic movements around 1.5 million years ago.
Volcanic ash rich in sodium minerals drains into the lake basin.
High evaporation rates concentrate salts.
Why the lake appears blood-red
During dry seasons, evaporation increases salinity.
Salt-loving microorganisms (haloarchaea and cyanobacteria) dominate.
Their pigments give the water a red and orange hue.
The coloration is visible even from aircraft.
Why animals appear “petrified”
The lake has a pH of ~10.5 (highly alkaline).
Rich in sodium carbonate.
Causes rapid dehydration of unadapted organisms.
Carcasses near the shore are preserved due to mineral deposition.
The process resembles mummification, not literal petrification.
Ecological importance
Despite extreme conditions, Lake Natron:
Serves as a major breeding ground for lesser flamingos.
Supports algae that flamingos feed on.
Harsh chemistry deters predators.
Plays a vital role in sustaining a large portion of the global flamingo population.
Prelims Practice MCQs
Q. With reference to Lake Natron, consider the following statements:
It is located in the Arusha Region of northern Tanzania.
It lies within the East African Rift System.
It is a freshwater lake formed primarily by glacial activity.
Which of the statements given above is/are correct?
A) 1 and 2 only
B) 2 only
C) 1 and 3 only
D) 1, 2 and 3
Answer: A
Explanation:
Statement 1 is correct — Lake Natron is in the Arusha Region of Tanzania.
Statement 2 is correct — it lies in the East African Rift Valley.
Statement 3 is incorrect — it is a highly alkaline saline lake, not glacial freshwater.
Q. The extreme alkalinity of Lake Natron is primarily due to:
A) High magnesium deposits from oceanic intrusion
B) Sodium-rich volcanic ash and intense evaporation
C) Industrial chemical discharge
D) Submarine hydrothermal vents
Answer: B
Explanation:
Volcanic activity, particularly from nearby Ol Doinyo Lengai, releases sodium-rich materials. High evaporation concentrates sodium carbonate, leading to a pH of around 10.5.