The great Sumatra-Andaman earthquakes : imaging the boundary between the ruptures of the great 2004 and 2005 earthquakes
Franke, D; Schnabel, M; Ladage, S; Tappin, David; Neben, S,; Djajadihardja, Y S; Muller, C,; Kopp, H,; Gaedicke, C.. 2008 The great Sumatra-Andaman earthquakes : imaging the boundary between the ruptures of the great 2004 and 2005 earthquakes. Earth & Planetary Science Letters, 269 (1-2). 118-130. 10.1016/j.epsl.2008.01.047Before downloading, please read NORA policies.
Segmentation along convergent margins controls earthquake magnitude and location, but the physical causes of segment boundaries, and their impact on earthquake rupture dynamics, are still poorly understood. One aspect of the 2004 and 2005 great Sumatra-Andaman earthquakes is their abrupt termination along a common boundary. This has led to speculation on the nature of the boundary, its origin and why it was not breached. For the first time the boundary has been imaged and, with newly acquired marine geophysical data, we demonstrate that a ridge on the subducting Indo-Australian oceanic crust may exert a control on margin segmentation. This suggests a lower plate influence on margin structure, particularly its segmentation. The ridge is masked by the sedimentary cover in the trench. Its most likely trend is NNE-SSW. It is interpreted as a fracture zone on the subducting oceanic plate. A ramp or tear along the eastern flank of the subducting fracture zone beneath Simeulue Island may be considered as an intensification factor in terms of rupture propagation barrier.
|Programmes:||BGS Programmes 2008 > Marine Geoscience|
|Additional Keywords:||Subduction, Earthquakes, Segmentation, Seismic data, Sumatra|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||01 Aug 2008 14:54|
Actions (login required)