Report on Nyamulagira (DR Congo) — 25 January-31 January 2012
Smithsonian Institution / US Geological Survey
Weekly Volcanic Activity Report, 25 January-31 January 2012
Managing Editor: Sally Sennert.
Please cite this report as:
Global Volcanism Program, 2012. Report on Nyamulagira (DR Congo) (Sennert, S, ed.). Weekly Volcanic Activity Report, 25 January-31 January 2012. Smithsonian Institution and US Geological Survey.
1.408°S, 29.2°E; summit elev. 3058 m
All times are local (unless otherwise noted)
The VolcanoDiscovery Team observed the fissure eruption at Nyamuragira that began on 6 November 2011 during 22-25 January 2012 from the newly formed cinder cones located about 10 km E of the summit crater. They reported three coalescent cones with the largest cone containing a small lava lake. The lake ejected spatter every few seconds as high as 200 m above the summit; individual bombs reached the base of the cone. Lava flows from the vent extended several kilometers N. Numerous small breakouts formed secondary flows, and a large breakout about 2 km N of the cone fed a large lava flow about 20 m wide. Burning forests were reported to the NNE.
Geological Summary. Africa's most active volcano, Nyamulagira (also known as Nyamuragira), is a massive high-potassium basaltic shield about 25 km N of Lake Kivu and 13 km NNW of the steep-sided Nyiragongo volcano. The summit is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Documented eruptions have occurred within the summit caldera, as well as from the numerous flank fissures and cinder cones. A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Recent lava flows extend down the flanks more than 30 km from the summit as far as Lake Kivu; extensive lava flows from this volcano have covered 1,500 km2 of the western branch of the East African Rift.