Results

Some block motions are well defined and vary little within our model. The Eurasian block, Australian block, and Indian block rotation parameters are defined primarily by the sites that lie within the stable interior and are affected very little by plate boundary strain. With respect to Eurasia the pole of rotation for the Indian plate is located at 23.641$\pm$0.979$^{\circ}$N 8.732$\pm$4.402$^{\circ}$E with an angular rotation rate of 0.359$\pm$0.012$^{\circ}$ Myr-1 (Figure 2.43). Relative poles shown in Figure 2.43 illustrate the consistency of our solution.

Along the Himalayan Range Front we estimate IND-EUR convergence to vary from 34-41 mm/yr from $\sim$76 $^{\circ}$-91 $^{\circ}$ east longitude (Figure 2.44, inset). We parameterize the Himalayan front with four main blocks defined by the major geologic features like the Indus-Zangbo suture, Gulu rift, and Karakorum fault. As much as 25 mm/yr of contraction is accommodated by the Himalayan thrust (Figure 2.44). Our model, along the front, fit the data quite well. Some systematic misfit with the Himalayan blocks may be related to unmodeled east-west extension.

Figure 2.43: Relative plate poles of India's motion with respect to Eurasia. Values that precede the reference are the poles' magnitude measured in deg/My with a counter-clockwise positive convention.

Figure 2.44: Velocity profile of measured and predicted velocities in Tibet. The inset figure shows the block configuration used in the inversion. GPS stations are colored according to source.