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No.85 (2008/3) >

 
Title :FE modeling of contemporary tectonic stress in the India-Eurasia collision zone
Authors :Chamlagain, Deepak
Hayashi, Daigoro
Authors alternative :林, 大五郎
Issue Date :Mar-2008
Abstract :An understanding of orientation of contemporary maximum horizontal compressive stress (σ_<Hmax>) is important to many aspects of earth sciences, e.g. seismicity, neotectonics, and plate driving mechanisms. Comparison of recent stress observations and the results of stress modeling provide a powerful approach to refine our understanding of geodynamics processes. This is especially important for complex area like Himalayan-Tibet orogen, a continental collision zone between the Indian and Eurasian Plates. The frequently occurring earthquakes and other tectonic stress indicator have provided vast set of database on maximum horizontal compressive stress (σ_<Hmax>) that can be useful to study contemporary stress sources, plate kinematics and ongoing geodynamics. In this contribution, taking advantage of elastic plane stress finite element modeling (FEM), and observed data on σ_<Hmax>, several models are presented to reproduce stress field. Simulated models show that the convergence normal to the orogen is essential to reproduce observed σ_<Hmax>, which in turn controls the magnitude and orientation of σ_<Hmax>. The kinematics equivalent to east-west tectonic escape did not reproduce the observed stress field. Therefore, the best-fit model of present day stress field is obtained only in three domains model with southeastward tectonic escape of the Tibetan crust rather than eastward extrusion. There is, however, significant increase in σ_<Hmax> magnitude with increasing crustal depth because of stress amplification. Incorporation of suture zones in the model did not change orientation of σ_<Hmax>, significantly. Considering these facts, 'continuum tectonic model' is more preferable than the 'block tectonic model' for the active deformation of the Tibetan Plateau. Contemporary stress field deduced from several tectonic stress markers reconciles with the predicted one giving insights on their sources and ongoing plate kinematics of the continental collision zone between Indian and Eurasian Plates.
Type Local :紀要論文
ISSN :0286-9640
Publisher :琉球大学理学部
URI :http://hdl.handle.net/20.500.12000/5609
Citation :琉球大学理学部紀要 = Bulletin of the College of Science. University of the Ryukyus no.85 p.39 -79
Appears in Collections:No.85 (2008/3)

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