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Modelling the seismic potential of the Indo-Burman megathrust

The Indo-Burman arc is the boundary between the India and Burma plates, north of the Sumatra–Andaman subduction zone. The existence of active subduction in the Indo-Burman arc is a debatable issue because the Indian plate converges very obliquely beneath the Burma plate. Recent GPS measurements in B...

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Autores principales: Vorobieva, Inessa, Gorshkov, Alexander, Mandal, Prantik
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8551320/
https://www.ncbi.nlm.nih.gov/pubmed/34707146
http://dx.doi.org/10.1038/s41598-021-00586-y
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author Vorobieva, Inessa
Gorshkov, Alexander
Mandal, Prantik
author_facet Vorobieva, Inessa
Gorshkov, Alexander
Mandal, Prantik
author_sort Vorobieva, Inessa
collection PubMed
description The Indo-Burman arc is the boundary between the India and Burma plates, north of the Sumatra–Andaman subduction zone. The existence of active subduction in the Indo-Burman arc is a debatable issue because the Indian plate converges very obliquely beneath the Burma plate. Recent GPS measurements in Bangladesh, Myanmar, and northeast India indicate 13–17 mm/y of plate convergence along a shallow dipping megathrust while most of the strike-slip motion occurs on several steep faults, consistent with patterns of strain partitioning at subduction zones. A short period of instrumentally recorded seismicity and sparse historical records are insufficient to assess the possibility of great earthquakes at the Indo-Burman megathrust. Using the advantage of the Block-and-Fault Dynamics model allowing simultaneous simulation of slow tectonic motions and earthquakes, we test the hypothesis whether the India-Burma detachment is locked and able to produce great earthquakes, or it slips aseismically? We have shown that the model of locked detachment is preferred because it more adequately reproduces observed tectonic velocities. The integral characteristics of synthetic seismicity, the earthquake size distribution, and the rate of seismic activity are consistent with those derived from observations. Our results suggest that the megathrust is locked and can generate great M8+ earthquakes. The estimated average return period of great events exceeds one thousand years. Earthquakes of this size pose a great threat to NE India, Bangladesh and Myanmar, the most densely populated areas of the world.
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spelling pubmed-85513202021-11-01 Modelling the seismic potential of the Indo-Burman megathrust Vorobieva, Inessa Gorshkov, Alexander Mandal, Prantik Sci Rep Article The Indo-Burman arc is the boundary between the India and Burma plates, north of the Sumatra–Andaman subduction zone. The existence of active subduction in the Indo-Burman arc is a debatable issue because the Indian plate converges very obliquely beneath the Burma plate. Recent GPS measurements in Bangladesh, Myanmar, and northeast India indicate 13–17 mm/y of plate convergence along a shallow dipping megathrust while most of the strike-slip motion occurs on several steep faults, consistent with patterns of strain partitioning at subduction zones. A short period of instrumentally recorded seismicity and sparse historical records are insufficient to assess the possibility of great earthquakes at the Indo-Burman megathrust. Using the advantage of the Block-and-Fault Dynamics model allowing simultaneous simulation of slow tectonic motions and earthquakes, we test the hypothesis whether the India-Burma detachment is locked and able to produce great earthquakes, or it slips aseismically? We have shown that the model of locked detachment is preferred because it more adequately reproduces observed tectonic velocities. The integral characteristics of synthetic seismicity, the earthquake size distribution, and the rate of seismic activity are consistent with those derived from observations. Our results suggest that the megathrust is locked and can generate great M8+ earthquakes. The estimated average return period of great events exceeds one thousand years. Earthquakes of this size pose a great threat to NE India, Bangladesh and Myanmar, the most densely populated areas of the world. Nature Publishing Group UK 2021-10-27 /pmc/articles/PMC8551320/ /pubmed/34707146 http://dx.doi.org/10.1038/s41598-021-00586-y Text en © The Author(s) 2021 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
Vorobieva, Inessa
Gorshkov, Alexander
Mandal, Prantik
Modelling the seismic potential of the Indo-Burman megathrust
title Modelling the seismic potential of the Indo-Burman megathrust
title_full Modelling the seismic potential of the Indo-Burman megathrust
title_fullStr Modelling the seismic potential of the Indo-Burman megathrust
title_full_unstemmed Modelling the seismic potential of the Indo-Burman megathrust
title_short Modelling the seismic potential of the Indo-Burman megathrust
title_sort modelling the seismic potential of the indo-burman megathrust
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8551320/
https://www.ncbi.nlm.nih.gov/pubmed/34707146
http://dx.doi.org/10.1038/s41598-021-00586-y
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