Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/80777
Title: Implications of the diffuse deformation of the Indian Ocean lithosphere for slip partitioning of oblique plate convergence in Sumatra
Authors: Bradley, Kyle Edward
Feng, Lujia
Hill, Emma Mary
Natawidjaja, D. H.
Sieh, Kerry
Keywords: Subduction
Geodesy
Issue Date: 2016
Source: Bradley, K. E., Feng, L., Hill, E. M., Natawidjaja, D. H., & Sieh, K. (2017). Implications of the diffuse deformation of the Indian Ocean lithosphere for slip partitioning of oblique plate convergence in Sumatra. Journal of Geophysical Research: Solid Earth, 122(1), 572-591.
Series/Report no.: Journal of Geophysical Research: Solid Earth
Abstract: Oblique plate convergence between Indian Ocean lithosphere and continental crust of the Sunda plate is distributed between subduction on the Sunda megathrust and upper plate strike-slip faulting on the Sumatran Fault Zone, in a classic example of slip partitioning. Over the last decade, a destructive series of great earthquakes has brought renewed attention to the mechanical properties of these faults and the intervening fore-arc crustal block. While observations of fore-arc deformation over the earthquake cycle indicate that the fore-arc crust is fundamentally elastic, the spatial pattern of slip vector azimuths for earthquakes sourced by rupture of the Sunda megathrust is strongly inconsistent with relative motion of two rigid plates. Permanent and distributed deformation therefore occurs in either the downgoing lithospheric slab or the overriding fore-arc crust. Previous studies have inferred from geodetic velocities and geological slip rates of the Sumatran Fault that the fore-arc crust is undergoing rapid trench-parallel stretching. Using new geological slip rates for the Sumatran Fault and an updated decadal GPS velocity field of Sumatra and the fore-arc islands, we instead show that permanent deformation within the fore-arc sliver is minor and that the Sumatran Fault is a plate boundary strike-slip fault. The kinematic data are best explained by diffuse deformation within the oceanic lithosphere of the Wharton Basin, which accommodates convergence between the Indian and Australian plates and has recently produced several large earthquakes well offshore of Sumatra. The slip partitioning system in Sumatra is fundamentally linked with the mechanical properties of the subducting oceanic lithosphere.
URI: https://hdl.handle.net/10356/80777
http://hdl.handle.net/10220/42240
ISSN: 2169-9313
DOI: 10.1002/2016JB013549
Rights: © 2016 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:EOS Journal Articles

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