Magma degassing triggered by static decompression at Kīlauea Volcano, Hawai‘i

During mid‐June 2007, the summit of Kīlauea Volcano, Hawai‘i, deflated rapidly as magma drained from the subsurface to feed an east rift zone intrusion and eruption. Coincident with the deflation, summit SO2 emission rates rose by a factor of four before decaying to background levels over several we...

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Bibliographic Details
Published inGeophysical research letters Vol. 36; no. 16; pp. L16306 - n/a
Main Authors Poland, Michael P., Sutton, A. Jeff, Gerlach, Terrence M.
Format Journal Article
LanguageEnglish
Published American Geophysical Union 01.08.2009
Subjects
deformation
degassing
Eruption mechanisms and flow emplacement
Geodesy and Gravity
Kilauea
Seismic cycle related deformations
Volcanic gases
Volcanic hazards and risks
Volcano monitoring
Volcanology
Kilauea
deformation
degassing
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Summary:During mid‐June 2007, the summit of Kīlauea Volcano, Hawai‘i, deflated rapidly as magma drained from the subsurface to feed an east rift zone intrusion and eruption. Coincident with the deflation, summit SO2 emission rates rose by a factor of four before decaying to background levels over several weeks. We propose that SO2 release was triggered by static decompression caused by magma withdrawal from Kīlauea's shallow summit reservoir. Models of the deflation suggest a pressure drop of 0.5–3 MPa, which is sufficient to trigger exsolution of the observed excess SO2 from a relatively small volume of magma at the modeled source depth beneath Kīlauea's summit. Static decompression may also explain other episodes of deflation accompanied by heightened gas emission, including the precursory phases of Kīlauea's 2008 summit eruption. Hazards associated with unexpected volcanic gas emission argue for increased awareness of magma reservoir pressure fluctuations.
ISSN:0094-8276
1944-8007
DOI:10.1029/2009GL039214