and Nyiragongo is an active stratovolcano with an elevation of 3,470 m (11,385 ft) in the Virunga Mountains associated with the Albertine Rift. It is located inside Virunga National Park, in the Democratic Republic of the Congo, about 12 km (7.5 mi) north of the town of Goma and Lake Kivu and just west of the border with Rwanda. The main crater is about two kilometres (1 mi) wide and usually contains a lava lake. The crater presently has two distinct cooled lava benches within the crater walls – one at about 3,175 m (10,417 ft) and a lower one at about 2,975 m (9,760 ft).
Mount Nyiragongo's lava lake
Satellite image of the eruption plume from Nyiragongo in July 2004
Nyiragongo, 2014
A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and periodic intervals of explosive eruptions and effusive eruptions, although some have collapsed summit craters called calderas. The lava flowing from stratovolcanoes typically cools and solidifies before spreading far, due to high viscosity. The magma forming this lava is often felsic, having high to intermediate levels of silica, with lesser amounts of less viscous mafic magma. Extensive felsic lava flows are uncommon, but have traveled as far as 15 km (9 mi).
Mount Rainier, a 4,392 m (14,411 ft) stratovolcano, the highest point in the US state of Washington
Exposed internal structure of alternating layers of lava and pyroclastic rock in the eroded Broken Top stratovolcano in Oregon
Mount Etna on the island of Sicily, in southern Italy
Snow-like blanket of Mount Pinatubo's ashfall deposits in a parking lot on Clark Air Base (June 15, 1991)