Shear velocity structure across the Sumatran Forearc-Arc

Details Shear velocity structure across the Sumatran Forearc-Arc Shear velocity structure across the Sumatran Forearc-Arc

Apr 2012

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012geoji.tmp..538h&link_type=abstract

Geophysical Journal International, Online Early

Physics

Interferometry, Surface Waves And Free Oscillations, Subduction Zone Processes, Intraplate Processes, Continental Margins: Convergent, Crustal Structure

Scientific paper

We present a series of 1-D shear velocity models for the Sumatran Forearc and Arc derived from Rayleigh wave group dispersion in noise correlation functions from vertical and pressure records from an onshore-offshore seismic deployment. The 1-D models represent the crustal structure of the downgoing Indian Plate, the accretionary prism and the arc. There is a progression in shear velocity across the forearc to the arc associated with thickening of the accretionary prism and the development of an arc crust. The velocity structure inferred for the upper 20 km based on path averages between stations on the accretionary prism has velocities consistent with a thick sediment package in agreement with estimates of depth to the plate boundary determined from active source experiments. We also find low Indian Plate shear velocities, <4 km s-1 to 25 km depth beneath our station locations on the downgoing plate. These low seismic velocities are consistent with at least 14-24 per cent serpentinization of the oceanic crust and upper mantle of the downgoing plate. This high degree of serpentinization, may weaken the plate interface and explain the segmentation observed in the great Sumatran thrust earthquakes if the serpentinization is localized. The success of this study suggests that future onshore-offshore seismic deployments will be able to utilize this method.

Affiliated with

Also associated with

No associations

Rating

Shear velocity structure across the Sumatran Forearc-Arc does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Shear velocity structure across the Sumatran Forearc-Arc, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shear velocity structure across the Sumatran Forearc-Arc will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1116922