Report on Karthala (Union of the Comoros) — March 1977
Natural Science Event Bulletin, vol. 2, no. 3 (March 1977)
Managing Editor: David Squires.
Karthala (Union of the Comoros) Effusive eruption in early April causes evacuations
Please cite this report as:
Global Volcanism Program, 1977. Report on Karthala (Union of the Comoros) (Squires, D., ed.). Natural Science Event Bulletin, 2:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197703-233010
Karthala
Union of the Comoros
11.7658°S, 43.3639°E; summit elev. 2350 m
All times are local (unless otherwise noted)
An effusive eruption was reported on 6 April. About 4,000 people were evacuated from the path of the lava, which was flowing towards the sea. No deaths have occurred.
Geological Summary. The southernmost and largest of the two shield volcanoes forming Grand Comore Island (also known as Ngazidja Island), Karthala has two overlapping 3-4 km summit calderas generated by repeated collapse. Elongated rift zones extend NNW and SE from the summit of the basaltic shield, which has an asymmetrical profile that is steeper to the S. The lower SE rift zone forms the Massif du Badjini, a peninsula at the SE tip of the island. More than twenty eruptions have been recorded since the 19th century from the summit caldera and vents on the N and S flanks, producing many lava flows that reached the sea on both sides of the island. An 1860 CE lava flow from the summit caldera traveled ~13 km to the NW, reaching the W coast to the N of the capital city of Moroni.
Information Contacts: G. Beauchamp, OFDA.
