Report on Nyiragongo (DR Congo) — January 1977
Natural Science Event Bulletin, vol. 2, no. 1 (January 1977)
Managing Editor: David Squires.
Nyiragongo (DR Congo) Effusive eruption towards the SE engulfs two villages; significant number of deaths
Please cite this report as:
Global Volcanism Program, 1977. Report on Nyiragongo (DR Congo). In: Squires, D (ed.), Natural Science Event Bulletin, 2:1. Smithsonian Institution. http://dx.doi.org/10.5479/si.GVP.NSEB197701-223030.
1.52°S, 29.25°E; summit elev. 3470 m
All times are local (unless otherwise noted)
Nyiragongo began erupting at about 1000 on 10 January, apparently from several flank craters. The eruption was primarily effusive, but a mushroom cloud was reported by the Brussels Domestic Service. Lava flows, mainly on the volcano's SE flank, are reported to have moved as much as 16 km from the volcano, engulfed two villages, and cut several roads. The eruption had probably ended by 11 January.
Earthquakes were felt in Bukavu, ~125 km SE of Nyiragongo, on 1 and 6 January. Most of the 65,000 residents of Goma, 12 km S of Nyiragongo, fled prior to the eruption because of "incessant" earth tremors. By the night of 10-11 January, many were returning to their homes. The 23 December eruption of Nyamuragira, 14 km NW of Nyiragongo, had apparently ended. Estimates of casualties range from none to 2,000, the latest (26 January) being 50-100.
Geologic Background. One of Africa's most notable volcanoes, Nyiragongo contained a lava lake in its deep summit crater that was active for half a century before draining catastrophically through its outer flanks in 1977. In contrast to the low profile of its neighboring shield volcano, Nyamuragira, 3470-m-high Nyiragongo displays the steep slopes of a stratovolcano. Benches in the steep-walled, 1.2-km-wide summit crater mark levels of former lava lakes, which have been observed since the late-19th century. Two older stratovolcanoes, Baruta and Shaheru, are partially overlapped by Nyiragongo on the north and south. About 100 parasitic cones are located primarily along radial fissures south of Shaheru, east of the summit, and along a NE-SW zone extending as far as Lake Kivu. Many cones are buried by voluminous lava flows that extend long distances down the flanks, which is characterized by the eruption of foiditic rocks. The extremely fluid 1977 lava flows caused many fatalities, as did lava flows that inundated portions of the major city of Goma in January 2002.
Information Contacts: Kigali DNS, Rwanda; Reuters; AZAP, Zaire; Brussels DNS; UPI; U.S. Dept. of State.