HR: 08:40h
AN: U51B-03    [Abstracts]
TI: Diffuse Crustal Deformation in Asia: From Kinematics to Geodynamics
AU: * Liu, M
EM: lium@missouri.edu
AF: Dept. of Geological Sciences, University of Missouri-Columbia, 101 Geology Building, Columbia, MO 65211 United States
AU: Zhang, H
EM: huaizhang@hotmail.com
AF: Dept. of Geological Sciences, University of Missouri-Columbia, 101 Geology Building, Columbia, MO 65211 United States
AU: Zhang, H
EM: huaizhang@hotmail.com
AF: Laboratory of Computational Geodynamics, The graduate school of Chinese Academy of Sciences, No. 19 Jia, Yuquan Road, Beijing, 100049 China
AU: Yang, Y
EM: yangyou@missouri.edu
AF: Dept. of Geological Sciences, University of Missouri-Columbia, 101 Geology Building, Columbia, MO 65211 United States
AU: Wang, S
EM: wangshi@missouri.edu
AF: Dept. of Geological Sciences, University of Missouri-Columbia, 101 Geology Building, Columbia, MO 65211 United States
AB: Asian continent is a classical example of broadly diffuse crustal deformation that defies the prediction of the plate tectonics theory. The kinematics of Asian crust delineated by extensive neotectonics studies and GPS measurements are now sufficient to constrain the cause of the diffuse deformation. Using these constraints, we have developed a 3D viscous shell model to explore the dynamic interplay of major driving forces and lithospheric structure in controlling Asian tectonics. Calculated on parallel computers, the finite element model has nearly one million nodes, allowing inclusion of most major faults and lithospheric structures. Our preliminary results indicate that the effects of the plate boundary force from the Indian indenter are largely limited to the Tibetan Plateau and surrounding regions; active crustal deformation in much of the east and southeast Asia is mainly driven by the gravitational potential energy from the Tibetan Plateau and other uplifted landmasses in central Asia. Subduction along the eastern margin of the Eurasian plate has only secondary impact on active tectonics in east Asia, but may be important during the early Cenozoic. The large lateral heterogeneity of lithospheric structure causes strain to localize within narrow deforming zones marked by active fault systems. The predicted deviatoric stress is relatively high in the North China block but low in the South China block, consistent with the contrasting seismicity between these regions. The total seismic energy released in the past two thousand years is comparable to the predicted long-term spatial pattern of strain energy in China.
DE: 8011 Kinematics of crustal and mantle deformation
DE: 8107 Continental neotectonics (8002)
DE: 8150 Plate boundary: general (3040)
DE: 8164 Stresses: crust and lithosphere
SC: Union [U]
MN: Fall Meeting 2005