HR: 14:40h
AN: T22C-05 INVITED     [PDF]
TI: GPS Measurements from the Southern Tibetan Plateau: Tests of Plate-like or Continuous Deformation
AU: * Bendick, R
EM: bendick@esc.cam.ac.uk
AF: COMET, Bullard Laboratories Madingley Road, Cambridge, CB3 0EZ United Kingdom
AU: * Bendick, R
EM: bendick@esc.cam.ac.uk
AF: CIRES, CB 399 University of Colorado, Boulder, CO 80309-0399 United States
AU: Jade, S
EM: sridevi@cmmacs.ernet.in
AF: CSIR, CMMACS, Bangalore, 5650037 India
AU: Bhatt, B
EM: bhatt@cmmacs.ernet.in
AF: Indian Institute of Astrophysics, none, Bangalore, 560034 India
AU: Gaur, V
EM: gaur@cmmacs.ernet.in
AF: CSIR, CMMACS, Bangalore, 5650037 India
AU: Molnar, P
EM: molnar@cires.colorado.edu
AF: CIRES, CB 399 University of Colorado, Boulder, CO 80309-0399 United States
AU: Anand, M
EM: anand@cmmacs.ernet.in
AF: CSIR, CMMACS, Bangalore, 5650037 India
AU: Kumar, D
EM: kumar@ecmmacs.ernet.in
AF: CSIR, CMMACS, Bangalore, 5650037 India
AB: Observations of relative motion in a geodetic network in Ladakh, India, and across southern Tibet indicate slow shear on the Karakorum fault, rapid east-west extension across the whole of southern Tibet, and constant arc-normal convergence between India and southern Tibet along the Himalayan arc. Measurements of ten campaign-style and six permanent sites with GPS precise geodesy provide bounds on the style and rate of surface deformation in the Tibet-Himalaya region. Divergence between sites at Leh, Ladakh, India and Shiquanhe, western Tibet as well as slow relative motion among sites within the Ladakh network limit right-lateral slip parallel to the Karakorum fault to only 3-5 mm/yr (1 $\sigma$). This low rate concurs with a recent estimate of 3-4 mm/yr for late Holocene time, but disagrees with the much higher rate of 30-35 mm/yr that has been used to argue for plate-like behavior of the Tibetan Plateau. Convergence between the Indian subcontinent and Ladakh at 15.5 $\pm$ 1.7 mm/yr at N42 $\deg$ E $\pm$ 3$\deg$ (1 $\sigma$) differs little from estimates of convergence across the central segment of the Himalaya. Finally, lengthening of the baseline between Leh, Ladakh and Lhasa (in southeastern Tibet) at 17.8 $\pm$ 1 mm/yr is consistent with an extrapolation of rates of east-west extension of the Tibetan Plateau based both on shorter GPS baselines and on diverging slip vectors of earthquakes in the Himalaya and suggests no significant acceleration associated with the Karakorum fault.
DE: 8010 Fractures and faults
DE: 8020 Mechanics
DE: 8107 Continental neotectonics
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8159 Rheology--crust and lithosphere
SC: Tectonophysics [T]
MN: 2003 Fall Meeting