Report on Nyiragongo (DR Congo) — 9 October-15 October 2002
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 9 October-15 October 2002
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2002. Report on Nyiragongo (DR Congo). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 9 October-15 October 2002. Smithsonian Institution and US Geological Survey.
1.52°S, 29.25°E; summit elev. 3470 m
All times are local (unless otherwise noted)
During a flight over Nyiragongo on 27 September, researchers' views into the crater were obscured by a large gas plume. The plume was present from mid-September through at least 10 October and reached to ~3 km above the volcano. During some nights from late September to 10 October, red glow reflecting off of the cloud was visible from towns near the volcano. The glow was caused by Strombolian explosions and the light emitted by the combustion of gases. While visiting the volcano during this time period, researchers heard loud noises emanating from the crater, and saw that volcanic material was ejected ~150 m vertically and no lava lake was visible. On 6 October they heard a partial wall collapse in the internal crater.
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.
Source: Goma Volcano Observatory (GVO)