Seismic Reflection Image of the Great Sumatra Earthquake Rupture Zone Using Seismic Industry Technology

Singh, S. C.; Carton, H. D.; Bayly, Martin

doi:10.3997/2214-4609.201400323

Cited by 1 publication

(1 citation statement)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Features with slopes >5° indicate potentially active structures, e.g., as blind thrusts, surface-breaking faults or submarine canyons. The interpretation of the widespread elongate sub-parallel ridges and related landward and seaward vergent thrusts (Henstock et al, 2006) is based on the geodynamic setting of the accretionary wedge where thrust (fault bend fold) type anticlines are commonly observed in nature (Suppe, 1983;Flueh et al, 1998), analogic models (Gutscher et al, 1998) and seismic data from the region (e.g., Singh et al, 2006;Sibuet et al, 2007;Franke et al, 2006 andGaedicke et al, 2006). On Figure 3, we mark thrusts and discontinuities in the fold axes with different symbols based on there clarity.…”

Section: Sea-floor Slope and Morpho-tectonic Mapsmentioning

confidence: 99%

Impact of lower plate structure on upper plate deformation at the NW Sumatran convergent margin from seafloor morphology

Graindorge

Klingelhoëfer

Sibuet

et al. 2008

Earth and Planetary Science Letters

View full text Add to dashboard Cite

International audienceWe present results from multibeam bathymetric data acquired during 2005 and 2006, in the region of maximum slip of the 26 Dec. 2004 earthquake (Mw 9.2). These data provide high-resolution images of seafloor morphology of the entire NW Sumatra forearc from the Sunda trench to the submarine volcanic arc just north of Sumatra. A slope gradient analysis of the combined dataset accurately highlights those portions of the seafloor shaped by active tectonic, depositional and/or erosional processes. The greatest slope gradients are located in the frontal 30 km of the forearc, at the toe of the accretionary wedge. This suggests that long-term deformation rates are highest here and that probably only minor amounts of slip are accommodated by other thrust faults further landward. Obvious N–S oriented lineaments observed on the incoming oceanic plate are aligned sub-parallel to the fracture zones associated with the Wharton fossil spreading center. Active strike-slip motion is suggested by recent deformation with up to 20–30 m of vertical offset. The intersection of these N–S elongated bathymetric scarps with the accretionary wedge partly controls the geometry of thrust anticlines and the location of erosional features (e.g. slide scars, canyons) at the wedge toe. Our interpretation suggests that these N–S lineaments have a significant impact on the oceanic plate, the toe of the wedge and further landward in the wedge. Finally, the bathymetric data indicate that folding at the front of the accretionary wedge occurs primarily along landward-vergent (seaward-dipping) thrusts, an unusual style in accretionary wedges worldwide. The N–S elongated lineaments locally act as boundaries between zones with predominant seaward versus landward vergence

show abstract