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SO 2 emissions from basaltic eruptions, and the excess sulfur issue
Author(s) -
Sharma K.,
Blake S.,
Self S.,
Krueger A. J.
Publication year - 2004
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 - 10.1029/2004gl019688
Subject(s) - basalt , magma , geology , volcano , volcanology , sulfur , sulfur dioxide , atmosphere (unit) , geochemistry , total ozone mapping spectrometer , earth science , environmental science , atmospheric sciences , stratosphere , materials science , chemistry , meteorology , ozone layer , inorganic chemistry , physics , metallurgy
Volcanic SO 2 can affect the Earth's environment. Where no direct measurements of SO 2 in the atmosphere are available, a petrologic method of assessing sulfur release from the magma must be used. However, in studies of arc‐derived eruptions, satellite‐based measurements of SO 2 emissions using Total Ozone Mapping Spectrometer (TOMS) data are orders of magnitude greater than those calculated petrologically, implying that a separate S‐rich gas phase in the magma chamber may be responsible for the excess sulfur. We test whether this applies in other settings. For Icelandic and Hawaiian basalts we find that petrologic SO 2 values are comparable to measurements of SO 2 by TOMS. Thus, for non‐arc basalts, the petrologic method gives reliable estimates of SO 2 released. The implied absence of excess sulfur in non‐arc basaltic magmas is a reflection of source magma conditions, notably lower f O 2 and volatile contents than arc magmas, inhibiting the exsolution of a S‐rich gas prior to eruption.