THREAT IN VIRUNGA: UNDERSTANDING EXPLOSIVE ERUPTIONS OF NYAMURAGIRA
Olivine and pyroxene crystals from the 1912 Nyamuragira eruption have been handpicked from bulk lava, and suitable melt inclusions (MI; portions of magma caught within solidifying crystals that are brought to the surface within lava during eruptions) have been identified. These MI will be prepared and analyzed for sulfur, chlorine, and fluorine, as well as major and minor element concentrations using electron microprobe analysis. With this information, we will evaluate the degassing and crystallization history of the 1912 magma prior to eruption. Preliminary data from one 1912 MI show a higher magmatic sulfur concentration (3700 ppm) compared to 1938, 1948, 1986, and 2006 samples (1000-2000 ppm). Gathering additional MI data on the 1912 Nyamuragira eruption will help us determine why this particular eruption was more explosive than other eruptions of this volcano.