On 4 June a new eruption began at Nyiragongo, producing a plume that probably contained ash, was under ~6 km a.s.l., and stretched ~150 km SW. By 5 June the plume had extended to 185 km SW and was under ~4 km a.s.l. On 6 June, only a moderate plume stretching to the SW and a disconnected remnant of the earlier plume was observed in satellite imagery. This moderate plume drifting SW remained through 7 June. On 8 June an ash plume extended ~75 km SW at an altitude of ~5.5 km a.s.l.

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.

Source: Toulouse Volcanic Ash Advisory Centre (VAAC)