Report on Karthala (Comoros) — March 1977
Natural Science Event Bulletin, vol. 2, no. 3 (March 1977)
Managing Editor: David Squires.
Karthala (Comoros) Effusive eruption in early April causes evacuations
Please cite this report as:
Global Volcanism Program, 1977. Report on Karthala (Comoros) (Squires, D., ed.). Natural Science Event Bulletin, 2:3. Smithsonian Institution. https://doi.org/10.5479/si.GVP.NSEB197703-233010.
11.75°S, 43.38°E; summit elev. 2361 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.
Geologic Background. The southernmost and largest of the two shield volcanoes forming Grand Comore Island (also known as Ngazidja Island), Karthala contains a 3 x 4 km summit caldera generated by repeated collapse. Elongated rift zones extend to the NNW and SE from the summit of the Hawaiian-style 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. Historical eruptions have modified the morphology of the compound, irregular summit caldera. More than twenty eruptions have been recorded since the 19th century from the summit caldera and vents on the N and S flanks. Many lava flows have reached the sea on both sides of the island. An 1860 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.