All Supporting Information may be found in the online version of this article.
3-D active source tomography around Simeulue Island offshore Sumatra: Thick crustal zone responsible for earthquake segment boundary
Article first published online: 15 JAN 2013
©2013 American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 40, Issue 1, pages 48–53, 16 January 2013
How to Cite
2013), 3-D active source tomography around Simeulue Island offshore Sumatra: Thick crustal zone responsible for earthquake segment boundary, Geophys. Res. Lett., 40, 48–53, doi:10.1029/2012GL054148., , , , , , , , , , and (
- Issue published online: 29 JAN 2013
- Article first published online: 15 JAN 2013
- Manuscript Accepted: 29 NOV 2012
- Manuscript Revised: 27 NOV 2012
- Manuscript Received: 8 OCT 2012
- Natural Environment Research Council. Grant Number: NE/D004381/1
- active-source tomography;
- Sumatra subduction zone;
- plate interface
 We present a detailed 3-D P-wave velocity model obtained by first-arrival travel-time tomography with seismic refraction data in the segment boundary of the Sumatra subduction zone across Simeulue Island, and an image of the top of the subducted oceanic crust extracted from depth-migrated multi-channel seismic reflection profiles. We have picked P-wave first arrivals of the air-gun source seismic data recorded by local networks of ocean-bottom seismometers, and inverted the travel-times for a 3-D velocity model of the subduction zone. This velocity model shows an anomalous zone of intermediate velocities between those of oceanic crust and mantle that is associated with raised topography on the top of the oceanic crust. We interpret this feature as a thickened crustal zone in the subducting plate with compositional and topographic variations, providing a primary control on the upper plate structure and on the segmentation of the 2004 and 2005 earthquake ruptures.