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Influence of carbon dioxide on the large‐scale dynamics of magmatic eruptions at Phlegrean Fields (Italy)
Author(s) -
Esposti Ongaro Tomaso,
Papale Paolo,
Neri Augusto,
Del Seppia Dario
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl025528
Subject(s) - carbon dioxide , volcano , geology , saturation (graph theory) , volatiles , magma , volcanology , atmosphere (unit) , vulcanian eruption , atmospheric sciences , petrology , environmental science , mineralogy , geochemistry , chemistry , meteorology , physics , mathematics , organic chemistry , combinatorics
Carbon dioxide is the second most abundant volatile species in magmas after water (Johnson et al., 1994) but its role on eruption dynamics is still largely unknown. The effects of the presence of CO 2 in the Agnano Monte Spina eruption (4100 BP, Phlegrean Fields, Italy) are here evaluated by simulating the eruption dynamics from the base of the volcanic conduit up into the atmosphere. The numerical simulations consider multiphase flow dynamics and couple the steady‐state, one‐dimensional magma ascent model of Papale (2001) and the transient, axisymmetric pyroclast dispersal model of Neri et al. (2003). The main input parameters of the models were based on eruptive conditions estimated from the deposits. A parametric study has been performed on H 2 O and CO 2 concentrations in the erupted magma. The addition of CO 2 results in increased volatile saturation pressure and complex non‐linear changes in the conduit flow. Nonetheless, within the range of conditions explored, this volatile scarcely affects the eruption style and dynamics in the atmosphere, which are principally controlled by the H 2 O content. The different roles of the two volatiles in the large‐scale eruption dynamics are mostly the result of the competing changes induced by CO 2 on vent conditions.