3-D active source tomography around Simeulue Island offshore Sumatra: Thick crustal zone responsible for earthquake segment boundary
|Author(s)||Tang Genyang1, 8, Barton Penny J.1, McNeill Lisa C.2, Henstock Timothy J.2, Tilmann Frederik1, 3, Dean Simon M.2, Jusuf Muhammad D.4, Djajadihardja Yusuf S.4, Permana Haryadi5, Klingelhoefer Frauke6, Kopp Heidrun7|
|Affiliation(s)||1 : Univ Cambridge, Bullard Labs, Cambridge, England.
2 : Univ Southampton, Natl Oceanog Ctr Southampton, Southampton, Hants, England.
3 : Helmholtz Ctr Potsdam, GFZ German Res Ctr Geosci, Potsdam, Germany.
4 : Agcy Assessment & Applicat Technol BPPT, Jakarta, Indonesia.
5 : Indonesian Inst Sci LIPI, Bandung, Indonesia.
6 : IFREMER, Plouzane, France.
7 : GEOMAR Helmholtz Ctr Ocean Sci Kiel, Kiel, Germany.
8 : China Univ Petr, State Key Lab Petr Resource & Prospecting, Beijing, Peoples R China.
|Source||Geophysical Research Letters (0094-8276) (Amer Geophysical Union), 2013-01 , Vol. 40 , N. 1 , P. 48-53|
|WOS© Times Cited||11|
|Keyword(s)||active-source tomography, Sumatra subduction zone, segmentation, plate interface|
|Abstract||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.|