66: NASA satellite detects large plume from DR Congo’s Nyamuragira volcano

July 19, 2013 – DR CONGO, Africa – Recent NASA satellite images from 11 June 2013 show a thick steam and gas plume rising from a pit crater in the summit caldera of Nyamuragira volcano. No evidence of lava close to the surface was found, while the lava lake in neighboring Nyiragongo remains well active and visible on the same images. Nyamuragira’s plume was rich in water vapor — which condenses rapidly in the humid tropical air — and sulfur dioxide, which lends a blue tint in natural-color satellite imagery. Carbon dioxide, fluorine, and chlorine gas are also found in Nyamuragira lavas and likely present in the gas plume. Located near the eastern boundary of the Democratic Republic of the Congo, Nyamuragira is one of Africa’s most active volcanoes. If degassing magma was near the surface, then the intense heat would cause a bright red glow in shortwave infrared light. No such glow is visible atop Nyamuragira, but it is present on neighboring Nyiragongo Volcano, which has featured a lava lake for more than a decade. The images were collected on June 11, 2013, by the Operational Land Imager on Landsat 8. In natural color (top), the rainforest is dark green, clouds are white, and the sulfur-rich volcanic plume is very light blue. Barren land at Nyamuragira’s summit and lava flows is brown or black. In false-color, clouds are mostly white and volcanic plumes are cyan. Forest and other vegetation is bright green. Fresh lava flows from the 2011–12 eruption of Nyamuragira are black, and older lava flows appear as brown tendrils running down the mountain’s flanks. Agricultural fields in the southeast (lower right) corner of the image also appear brown. –Volcano Discovery

Seismic swarm near another Alaskan Volcano: A seismic swarm with magnitudes up to 3.5 has been occurring in the Wrangell Arc about 40 km NE of Mt. Churchill volcano during the past few days. The intensity and frequency of the quakes has calmed down yesterday. While some few of the quakes are near the volcano, most are not, and the swarm is probably not linked to the volcanic system of Mt Churchill volcano. Churchill is the fourth tallest volcano in the U.S. and has erupted in more than 1,300 years.  –VD