OL DOINYO LENGAI VOLCANO (Syllabus: GS Paper 1 – Geography)

Context: A new study reveals that the Ol Doinyo Lengai volcano has been both erupting magma above ground and sinking over the past decade. This dual phenomenon has been ongoing simultaneously for the last 10 years.

Ol Doinyo Lengai Volcano

• Location: Ol Doinyo Lengai is situated in northern Tanzania, at the southern end of Lake Natron.
• Significance: The local Maasai people refer to it as the “Mountain of God.”
• Geological Characteristics: It is an active stratovolcano with distinctive geological features and rises to an elevation of 9,442 feet (2,878 meters).
• Rift System: The volcano is part of the East African Rift System, which hosts several volcanoes.
• Unique Magma Composition: Its basalts are rich in sodium and potassium, and its lavas are so alkaline that they resemble washing soda.
• Active Craters: The volcano has multiple active centers, with recent eruptions primarily occurring from its northern crater.
• Rare Eruption Type: Ol Doinyo Lengai is unique for its actively erupting carbonatite magma, which is extremely runny, rich in alkali elements, and low in silica.
• Study Findings: Recent research indicates that since 2013, the crater’s upper slopes have been sinking due to a deflating magma reservoir located 3,300 feet (1,000 meters) beneath the surface.
• Data Collection: Researchers used data from Sentinel-1 and Cosmo-SkyMed satellite systems to map the changes in the ground around Ol Doinyo Lengai over time.
• Observations: Maps showed a circular ground patch around the northern crater, indicating a steady rate of displacement away from the satellite.