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Comparative velocity structure of active Hawaiian volcanoes from 3-D onshore–offshore seismic tomography

Citation

Park, J and Morgan, JK and Zelt, CA and Okubo, PG and Peters, L and Benesh, N, Comparative velocity structure of active Hawaiian volcanoes from 3-D onshore-offshore seismic tomography, Earth and Planetary Science Letters, 259, (3-4) pp. 500-516. ISSN 0012-821X (2007) [Refereed Article]

Copyright Statement

Copyright 2007 Elsevier B.V.

DOI: doi:10.1016/j.epsl.2007.05.008

Abstract

We present a 3-D P-wave velocity model of the combined subaerial and submarine portions of the southeastern part of the Island of Hawaii, based on first-arrival seismic tomography of marine airgun shots recorded by the onland seismic network. Our model shows that high-velocity materials (6.5–7.0 km/s) lie beneath Kilauea's summit, Koae fault zone, and the upper Southwest Rift Zone (SWRZ) and upper and middle East Rift Zone (ERZ), indicative of magma cumulates within the volcanic edifice. A separate high-velocity body of 6.5–6.9 km/s within Kilauea's lower ERZ and upper Puna Ridge suggests a distinct body of magma cumulates, possibly connected to the summit magma cumulates at depth. The two cumulate bodies within Kilauea's ERZ may have undergone separate ductile flow seaward, influencing the submarine morphology of Kilauea's south flank. Low velocities (5.0– 6.3 km/s) seaward of Kilauea's Hilina fault zone, and along Mauna Loa's seaward facing Kao'iki fault zone, are attributed to thick piles of volcaniclastic sediments deposited on the submarine flanks. Loihi seamount shows high-velocity anomalies beneath the summit and along the rift zones, similar to the interpreted magma cumulates below Mauna Loa and Kilauea volcanoes, and a low velocity anomaly beneath the oceanic crust, probably indicative of melt within the upper mantle. Around Kilauea's submarine flank, a high-velocity anomaly beneath the outer bench suggests the presence of an ancient seamount that may obstruct outward spreading of the flank. Mauna Loa's southeast flank is also marked by a large, anomalously high-velocity feature (7.0–7.4 km/s), interpreted to define an inactive, buried volcanic rift zone, which might provide a new explanation for the westward migration of Mauna Loa's current SWRZ and the growth of Kilauea's SWRZ.

Item Details

Item Type:Refereed Article
Keywords:volcanology, seismology
Research Division:Earth Sciences
Research Group:Geology
Research Field:Volcanology
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Environment not elsewhere classified
Author:Peters, L (Dr Leo Peters)
ID Code:103892
Year Published:2007
Web of Science® Times Cited:18
Deposited By:IMAS Research and Education Centre
Deposited On:2015-10-28
Last Modified:2015-11-17
Downloads:0

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