A report issued on 2 May noted an inferred renewal of activity on Nyamuragira. Residents living in the villages of Katale and Tongo, the settlements closest to the volcano, reported rumblings on 30 April, in addition to clear noises of individual explosions. At the same time on 30 April the closest seismic station (Katale) recorded 18 clear explosion signals, directly followed by an important tectonic earthquake located beneath the volcano. In the next hours seismometers registered 7 type-C events and another important tectonic earthquake.

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 15 km NE 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.

Source: Observatoire Volcanologique de Goma (OVG)