HR: 0800h
AN: T31B-0465    [Abstracts]
TI: Vertical axis rotations and gravity-driven flow in southeastern Tibet
AU: * Copley, A
EM: copley@esc.cam.ac.uk
AF: Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, United Kingdom
AU: Jackson, J
AF: Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, United Kingdom
AU: McKenzie, D
AF: Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, United Kingdom
AB: On the southeastern margin of the Tibetan Plateau lies a large region which seismicity and GPS data shows to be actively deforming. We describe the active faulting in the region, and suggest how this faulting accommodates the velocity field observed with GPS. We find that in places the velocity field is accommodated by rotations about vertical axes. We also compare the GPS velocities to velocities calculated using a model for thermomechanically coupled gravity-driven flow. For likely rheologies (estimated from experimentally derived mineral flow-laws) there is found to be good agreement between the model and GPS velocities. Two populations of normal faulting earthquakes are present in this area, and have mechanisms which are easily explained by gravity-driven deformation.
DE: 8110 Continental tectonics: general (0905)
DE: 8120 Dynamics of lithosphere and mantle: general (1213)
DE: 8159 Rheology: crust and lithosphere (8031)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting