Aseismic zone and earthquake segmentation associated with a deep subducted seamount in Sumatra

Singh_seam subd_2011

This article has been published in Nature Geoscience, 2011 . The authors have identified a seamount 3–4 km high and 40 km wide that has been subducted to a depth of 30–40 km below the Sumatra forearc mantle. The seamount has remained intact despite more than 160 km of subduction, and that there is no seismic activity either above or below the seamount. The authors suggest that the subduction of a topographic feature such as a seamount could lead to the segmentation of the subduction zone.

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New insight on the deformation along the southern Java forearc

This note is taken from an abstract presented at American Geophysical Union, Fall Meeting 2012. The new seismic data set in south Java resolved detailed structures of the southern Java forearc. The plate interface expressed as irregular surface in the western part and rather a continuous smooth boundary in the eastern area. This observation coincides with the higher uplift of the western part of the forearc high. Cluster of shallow earthquakes can be observed near the western part of Java trench. Deformation of the forearc high is more intense in the west compared to that in the east. This coincides with higher uplift of the western part of the forearc high, thus complicated the structures.

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