The 2008 eruption of Okmok Volcano, Alaska: Petrological and geochemical constraints on the subsurface magma plumbing system

Observing eruptions of gas-rich compressible magmas from space

“…1; the first representing perhaps the standard case, the second an end member, illustrating the range of possible behaviour. An explosive eruption occurred at Okmok Volcano on 12th July 2008 which ejected 0.15 Tg SO 2 (refs 42, 43) into the stratosphere, which was tracked across North America44. The eruption was followed by a period of subsidence45.…”

“…The eruption was followed by a period of subsidence45. A total of 0.26 km 3 (DRE) magma was erupted over the course of the eruption in the form of ash-rich explosions43. The erupted magma was a crystal-poor basaltic andesite bearing plagioclase, olivine and clinopyroxene phenocrysts, thought to have been remobilized by an intruding, more mafic magma43.…”

“…A total of 0.26 km 3 (DRE) magma was erupted over the course of the eruption in the form of ash-rich explosions43. The erupted magma was a crystal-poor basaltic andesite bearing plagioclase, olivine and clinopyroxene phenocrysts, thought to have been remobilized by an intruding, more mafic magma43. The magma reservoir was inferred to be at around 3 km depth in the early stages of the eruption, with deeper levels, up to 6 km, evacuated later in the eruption (from inversion of InSAR data45), which is supported by melt inclusion H 2 O concentrations, which range from 0.6 to 3.6 wt% (ref.…”

“…The magma reservoir was inferred to be at around 3 km depth in the early stages of the eruption, with deeper levels, up to 6 km, evacuated later in the eruption (from inversion of InSAR data45), which is supported by melt inclusion H 2 O concentrations, which range from 0.6 to 3.6 wt% (ref. 43). The r value (8.7; Fig.…”

High effusion rates of the Cordón Caulle 2011–2012 eruption (Southern Andes) and their relation with the quasi‐harmonic tremor

“…Indeed, there are some processes where harmonic or quasi-harmonic tremor is identified without lava flow emission. For example, Lascar volcano showed in April 1994 a harmonic tremor characterized by narrow and repetitive peaks at a same frequency, which were explained as movements of shallow [Richter and Eaton, 1960;Macdonald and Katsura, 1961], Etna 1981 [Guest et al, 1987], Piton de la Fournaise 1998 [Villeneuve, 2000;Vigouroux et al, 2009], Fernandina 1988 [Rowland, 1996;Allan and Simkin, 2000], Stromboli 2002 [Calvari et al, 2005;Landi et al, 2006], Krafla 1975 [Jónasson, 1994;Harris et al, 2000], Okmok 1997 [Patrick et al, 2003;Larsen et al, 2013], La Palma 1971 [Praegel and Holm, 2006], Merapi 2010 [Surono et al, 2012;Pallister et al, 2013b], Augustine 2006 Larsen et al, 2010], Lamington 1951 [Arculus et al, 1983], Tarumai 1909 [Ishikawa, 1952], Soufrière Hills 1995 [Devine et al, 1998;Sparks et al, 1998], Redoubt 2009[Coombs et al, 2013, St Helens 1980 [Swanson et al, 1987;Fink et al, 1990], Trident 1953[Coombs et al, 2000], Santiaguito 1922, Unzen 1990 [Nakada and Motomura, 1999;, Ilopango 1879 [Richer et al, 2004], Cordón Caulle 1960 [Lara et al, 2004], Cordón Caulle 2011 , and Chaitén 2008 [Pallister et al, 2013a].…”