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Abstract

Northeastern India and its surrounding are tectonically complex regions resulting from the collision of India and Eurasia. Due to complexities in the structural units at its northern, western and eastern boundaries, GPS velocities are not directly observable across any single fault system. The region is characterised by a high seismicity rate and produces more than 30% of earthquakes yearly in this region compared to the whole Himalayan belt. The region is surrounded by numerous major faults having creeps at the surface and has not produced a large earthquake since 1950. We invert Global Positioning System data with elastic block models to estimate the degree of locking on the major faults, slip rate, and block rotation and place bounds on the moment accumulation rate on the fault. The estimated slip rate along the CMF fault is ~ 12 mm/yr and dextral strike-slip motion. Our estimated slip along the Himalayan main boundary is significantly higher than that estimated earlier. Our slip model suggests that the observed fault kinematics can be attributed to the relative motion between different blocks and their rotations.