Report on Nyiragongo (DR Congo) — 20 April-26 April 2016
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 20 April-26 April 2016
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2016. Report on Nyiragongo (DR Congo). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 20 April-26 April 2016. Smithsonian Institution and US Geological Survey.
1.52°S, 29.25°E; summit elev. 3470 m
All times are local (unless otherwise noted)
On 12 April the Observatoire Volcanologique de Goma reported that activity at Nyiragongo had declined since 6 April, and that the level of the lava lake had dropped. A report dated 17 April stated that some volcanic earthquakes had been located within 5 km E and 10-15 km N of the crater; continuous volcanic tremor was recorded during 0200-0400 on 17 April. In a photo dated 19 April an incandescent vent atop a spatter cone appears to be in the same location as a lava lake that had been first noted on 1 March.
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)