Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arc

Abstract Segmentation of a subduction zone through tearing is envisaged as an inevitable consequence of the differential rate of slab rollback along the strike of convergent plate boundaries. It is a key feature that controls plate tectonics and seismogenesis in a subduction setting. Globally, litho...

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Main Authors: Prakash Kumar, G. Srijayanthi, M. Ravi Kumar
Format: Article
Language:English
Published: Wiley 2016-05-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2016GL068590
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author Prakash Kumar
G. Srijayanthi
M. Ravi Kumar
author_facet Prakash Kumar
G. Srijayanthi
M. Ravi Kumar
author_sort Prakash Kumar
collection DOAJ
description Abstract Segmentation of a subduction zone through tearing is envisaged as an inevitable consequence of the differential rate of slab rollback along the strike of convergent plate boundaries. It is a key feature that controls plate tectonics and seismogenesis in a subduction setting. Globally, lithospheric tears are mostly recognized by seismic tomography and seismicity trends. However, such an intriguing feature has never been imaged with high resolution. Here we present seismological evidence for tearing of the Indian oceanic plate at shallow depths along the Andaman arc. Our image of the subducted plate using the shear‐wave receiver function technique reveals three distinct plate segments. The middle lithospheric chunk has an abrupt offset of ~20 km relative to the northern and southern segments along the entire stretch of Andaman‐Nicobar Islands. We interpret that this abrupt offset in the base of the lithosphere is caused by the tearing of the subducted oceanic plate. For the plate age of ~80 to 60 Myr, the lithospheric thickness varies from ~40 to 70 km.
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spelling doaj-art-ccb70485ade843f785fce130cbddfe282025-08-20T03:49:37ZengWileyGeophysical Research Letters0094-82761944-80072016-05-0143104899490410.1002/2016GL068590Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arcPrakash Kumar0G. Srijayanthi1M. Ravi Kumar2CSIR‐National Geophysical Research Institute Hyderabad IndiaCSIR‐National Geophysical Research Institute Hyderabad IndiaCSIR‐National Geophysical Research Institute Hyderabad IndiaAbstract Segmentation of a subduction zone through tearing is envisaged as an inevitable consequence of the differential rate of slab rollback along the strike of convergent plate boundaries. It is a key feature that controls plate tectonics and seismogenesis in a subduction setting. Globally, lithospheric tears are mostly recognized by seismic tomography and seismicity trends. However, such an intriguing feature has never been imaged with high resolution. Here we present seismological evidence for tearing of the Indian oceanic plate at shallow depths along the Andaman arc. Our image of the subducted plate using the shear‐wave receiver function technique reveals three distinct plate segments. The middle lithospheric chunk has an abrupt offset of ~20 km relative to the northern and southern segments along the entire stretch of Andaman‐Nicobar Islands. We interpret that this abrupt offset in the base of the lithosphere is caused by the tearing of the subducted oceanic plate. For the plate age of ~80 to 60 Myr, the lithospheric thickness varies from ~40 to 70 km.https://doi.org/10.1002/2016GL068590tearsubduction zonelithospherereceiver functionsAndaman‐Nicobar Islands
spellingShingle Prakash Kumar
G. Srijayanthi
M. Ravi Kumar
Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arc
Geophysical Research Letters
tear
subduction zone
lithosphere
receiver functions
Andaman‐Nicobar Islands
title Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arc
title_full Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arc
title_fullStr Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arc
title_full_unstemmed Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arc
title_short Seismic evidence for tearing in the subducting Indian slab beneath the Andaman arc
title_sort seismic evidence for tearing in the subducting indian slab beneath the andaman arc
topic tear
subduction zone
lithosphere
receiver functions
Andaman‐Nicobar Islands
url https://doi.org/10.1002/2016GL068590
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AT gsrijayanthi seismicevidencefortearinginthesubductingindianslabbeneaththeandamanarc
AT mravikumar seismicevidencefortearinginthesubductingindianslabbeneaththeandamanarc