Intraplate Strike-Slip Faulting, Stress Accumulation, and Shear Localization of a Crust-Upper Mantle System With Nonlinear Viscoelastic Material

• Zhang, Xuelei

• Sagiya, Takeshi

Bibliographic Information

Other Title

• Intraplate Strike‐Slip Faulting, Stress Accumulation, and Shear Localization of a Crust‐Upper Mantle System With Nonlinear Viscoelastic Material

Abstract

We investigate the evolution of tectonic background stress and elastic as well as inelastic strain in a crust‐upper mantle system around an infinitely long vertical strike‐slip fault in a self‐consistent mechanical earthquake cycle model. In the early stage of the stress evolution, deformation of the crust and the upper mantle is dominated by a uniform simple shear. Shear localization in the lower crust starts when coseismic rupture extends to the entire brittle upper crust. Together with this transition, the earthquake recurrence intervals decrease by an order of magnitude due to a basal drag originated from a localized plastic flow of the lower crust. After the shear zone is fully developed in the lower crust, the fault slip rate catches up with the far‐field velocity and earthquakes starts to occur periodically. Such a steady state can be reached in several hundred thousand years from the beginning, which includes few hundreds of earthquake cycles. A shear zone with large cumulative strain needs a few million years to develop under an intraplate strike‐slip fault, which is much longer than the time for shear strain rate to be localized. The model successfully reproduced evolution of tectonic stress around an intraplate strike‐slip fault, interacting with the development of localized shear zone in the lower crust. The model demonstrates the importance of considering the whole mechanical system in which rheological structure and fault activities interacting with each other for the better understanding of the intraplate earthquakes.

Journal

• Journal of Geophysical Research: Solid Earth

  Journal of Geophysical Research: Solid Earth 123 (10), 9269-9285, 2018-10

  Wiley

Keywords

• earthquake cycle
• nonlinear Maxwell rheology
• plastic shear zone evolution

Details

• CRID: 1050282813790577152
• NII Article ID: 120006577089
• DOI: 10.1029/2018jb016421
• ISSN: 21699356
• ISSN: 21699313
• HANDLE: 2237/00029394
• Web Site: https://nagoya.repo.nii.ac.jp/records/27195
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1029%2F2018JB016421
• Web Site: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB016421
• Web Site: https://onlinelibrary.wiley.com/doi/full-xml/10.1029/2018JB016421
• Web Site: http://api.wiley.com/onlinelibrary/chorus/v1/articles/10.1029%2F2018JB016421
• Web Site: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2018JB016421
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
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  • CiNii Articles
  • KAKEN