Report on Nyiragongo (DR Congo) — 26 February-4 March 2003
Smithsonian / US Geological Survey Weekly Volcanic Activity Report,
26 February-4 March 2003
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2003. Report on Nyiragongo (DR Congo). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 26 February-4 March 2003. Smithsonian Institution and US Geological Survey.
1.52°S, 29.25°E; summit elev. 3470 m
All times are local (unless otherwise noted)
The level of volcanic activity at Nyiragongo as of 27 February was lower than during previous weeks when fine ash and Pele's hair fell in the city of Goma. Winds were no longer blowing ash and Pele's hair to the S, therefore Goma and other cities S of the volcano were no longer affected by tephra fall. Pele's hair and/or ash fell SW of Nyiragongo in the village of Rusayo, affecting the water supply. Residents of villages around the volcano reported seeing incandescence atop Nyiragongo during the evening. While visiting Nyiragongo's crater on 25 and 26 February, scientists found that the interior of the crater had changed since their last visit on 4 and 5 February. Vegetation had died in the main crater and heavy ashfall had occurred on the S flank. During the evening they saw intense lava fountaining, with lava reaching probably more than 100 m high, and a storm of Pele's hair.
Geological Summary. 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. The steep slopes of a stratovolcano contrast to the low profile of its neighboring shield volcano, Nyamuragira. 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.