Imaging the crustal magma sources beneath Mauna Loa and Kilauea volcanoes, Hawaii

Geology
By: , and 

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Abstract

Three-dimensional seismic P-wave traveltime tomography is used to image the magma sources beneath Mauna Loa and Kilauea volcanoes, Hawaii. High-velocity bodies (>6.4 km/s) in the upper 9 km of the crust beneath the summits and rift zones of the volcanoes correlate with zones of high magnetic intensities and are interpreted as solidified gabbro-ultramafic cumulates from which the surface volcanism is derived. The proximity of these high-velocity features to the rift zones is consistent with a ridge-spreading model of the volcanic flank. Southeast of the Hilina fault zone, along the south flank of Kilauea, low-velocity material (<6.0 km/s) is observed extending to depths of 9–11 km, indicating that the Hilina fault may extend possibly as deep as the basal decollement. Along the southeast flank of Mauna Loa, a similar low-velocity zone associated with the Kaoiki fault zone is observed extending to depths of 6–8 km. These two upper crustal low-velocity zones suggest common stages in the evolution of the Hawaiian shield volcanoes in which these fault systems are formed as a result of upper crustal deformation in response to magma injection within the volcanic edifice.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Imaging the crustal magma sources beneath Mauna Loa and Kilauea volcanoes, Hawaii
Series title Geology
DOI 10.1130/0091-7613(1997)025<0867:ITCMSB>2.3.CO;2
Volume 25
Issue 10
Year Published 1997
Language English
Publisher GSA Publications
Contributing office(s) Volcano Science Center
Description 4 p.
First page 867
Last page 870