Geophysical study of a magma chamber near Mussau Island, Papua New Guinea

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Abstract

Analysis of a 24-channel seismic-reflection data collected near Mussau Island, Papua New Guinea, shows a high-amplitude, negative-polarity reflection that we believe is from the top of a magma chamber.  The reflecting horizon lies at a depth of about 4.4 s subbottom and can be traced laterally for 2.6 km.  On shot gathers, the reflection demonstrates normal moveout appropriate for an in-place event.  The frequency spectrum of the reflection shows a decrease in high-frequency content when compared to the sea floor reflection, as would be expected for a deep subsurface event.  The polarity of the reflection event is negative, suggesting that the reflection horizon is the top of a low-velocity zone.  Magnetic data indicate that the ridge containing the reflecting horizon is magnetic, and the geology of Massau Island suggests that the ridge is volcanic in its origin.  We speculate that the high-amplitude reflection is from the top of a magma chamber some 7-11 km deep.

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Additional publication details

Publication type Book chapter
Title Geophysical study of a magma chamber near Mussau Island, Papua New Guinea
Volume 9
Year Published 1988
Language English
Publisher Circum-Pacific Council for Energy and Mineral Resources
Description 9 p.
Larger Work Type Book
Larger Work Title Geology and offshore resources of Pacific Island Arcs: New Ireland and Manus Region, Papa New Guinea
First page 211
Last page 219
Country Papa New Guinea
Other Geospatial Mussau Island
Online Only (Y/N) N
Additional Online Files (Y/N) N
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