Wednesday, November 29, 2006 9:36:02 AM
- Planet ark of 28 November 2006 at http://www.planetark.com/dailynewsstory.cfm/newsid/39182/story.htm
- Examiner.com of 28 November 2006 at http://www.examiner.com/a-423689~Volcano_Erupts_in_Eastern_Congo.html
Nyamuragira (also known as Nyamulagira) is a broad low-angle shield volcano located 14 km northwest of the steep-sided Nyiragongo volcano and about 25 km north of Lake Kivu in the East African Rift Valley - in the Virunga Mountains of the Democratic Republic of the Congo. Nyamuragira is Africa's most active volcano. The 3058 m high summit of Nyamuragira is truncated by a small 2 x 2.3 km caldera that has walls up to about 100 m high. Its last known eruption was in 2004. Historical lava flows extend down the flanks more than 30 km from the summit, reaching as far as Lake Kivu. Observation of the eruption is difficult because of the unrest in the region. The area around Nyamuragira is difficult to access and home to a number of armed rebel troops notoriously opposing the government army.
Geographical location: 1.408°S, 29.20°E. Nyamuragira and Nyiragongo together, are responsible for nearly two-fifths of Africa's historical eruptions. Nyamurigira erupts every one to two years.
The Western Rift, also called the Albertine Rift, is edged by some of the highest mountains in Africa, including the Virunga Mountains. The Virunga Mountains are world famous for their mountain gorillas. Edward (former lake Amin), Kivi and Tanganyika are 3 of the so-called Rift Valley lakes.
In the rift zone extensional deformation occurs because the underlying mantle is rising from below and stretching the overlying continental crust. Upwelling mantle may melt to produce magmas, which then rise to the surface (in volcanoes), often along faults produced by the extensional deformation.
See also my Blog on Earthquake – Lake Tanganyika.