Report on Nyamuragira (DR Congo) — 14 February-20 February 2001
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 14 February-20 February 2001
Managing Editor: Gari Mayberry
Please cite this report as:
Global Volcanism Program, 2001. Report on Nyamuragira (DR Congo). In: Mayberry, G (ed.), Weekly Volcanic Activity Report, 14 February-20 February 2001. Smithsonian Institution and US Geological Survey.
1.408°S, 29.2°E; summit elev. 3058 m
All times are local (unless otherwise noted)
According to a Reuters article, the eruption at Nyamuragira that was first observed on 6 February continued at least until 18 February. There were reports of lava flowing from three cones, "flames" rising 100 m above the volcano, and ash falling over an area of 20 to 30 km2 around the volcano. Lava flowed down the S flank of the volcano, threatening to reach roads running N from the town of Goma ~30 km away. Scientists from the Lwiro Natural Science Research Centre in Bukavu said abnormal activity was initially detected in December. There was a report of one injury from the volcanic activity; a man lost his leg after accidentally stepping into a lava flow. Officials said that the effect of ash fall on crops, pastures used for grazing, and the water supply could devastate the region.
Scientists from the University of Hawaii used MODIS to monitor the positions of the lava flows on the volcano. They created hot spot maps that show the positions of thermal anomalies that were detected on 7, 8, 11, and 12 February. An approximately 7x5 km large hot spot was detected on 7 February 7-10 km N of the summit. By 8 February the anomaly had increased in size and was oriented in a SSW-NNE direction; a second hot spot, ~13x6 km in size and oriented towards the E-ESE, was detected SSE of the summit. On 11 and 12 February the NNE-trending NE-flank hot spot reached a maximum distance of ~22 km and the E-trending S-flank hot spot extended ~17 km.
Geologic Background. Africa's most active volcano, Nyamuragira, is a massive high-potassium basaltic shield about 25 km N of Lake Kivu. Also known as Nyamulagira, it has generated extensive lava flows that cover 1500 km2 of the western branch of the East African Rift. The broad low-angle shield volcano contrasts dramatically with the adjacent steep-sided Nyiragongo to the SW. The summit is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Historical eruptions have occurred within the summit caldera, as well as from the numerous fissures and cinder cones on the flanks. A lava lake in the summit crater, active since at least 1921, drained in 1938, at the time of a major flank eruption. Historical lava flows extend down the flanks more than 30 km from the summit, reaching as far as Lake Kivu.