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3D Finite Element Modelling of Lithospheric Strength in Zagros Mountains
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Hamid Reza Nankali *   , Behzad Vosooghi , Farhad Sobouti , Khaled Hessami |
| National Cartographic Center of Iran |
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Abstract: (5740 Views) |
| A three-dimensional lithosphere model with horizontal dimensions of 1500×600 km. and a depth extent of 70 km. is constructed from available geophysical data to find out strength (as the maximum deviatoric stress the lithosphere supports at a given depth) in Arabia-Eurasia plate boundary zone. The constructed model is first used in the calculation of thermal initial condition and then strength envelopes were calculated using the obtained geotherm and rheological flow laws. Numerical models are run for initial temperature distributions representing cold and hot lithospheres with two different rheologies (wet and dry).The obtained mechanical structures were analyzed and compared with other geophysical data e.g., seismicity-depth and isotherm-depth distributions. Model results for wet and dry rheologies indicate that the depth of the brittle-ductile transition is about 8 km., and 11 km. for hot geotherm and 10.5 km. to14 km. and 21-28 for the cold one. The results are in good agreement with focal depth in the Zagros that most earthquakes occur in 8 to 15 km. depth (Tatar et al., 2004 and Jackson et al., 2008) that the long-term strength of the continental lithosphere resided only in its upper part, which was contained wholly within the crust. |
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| Keywords: Rheology, Finite-element methods, Brittle, Geotherm, Iran |
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Full-Text [PDF 1110 kb]
(1980 Downloads)
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Type of Study: Research |
Received: 2015/02/19 | Accepted: 2015/02/19 | Published: 2015/02/19
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