Estimates of motion and strain rates across active faults in the frontal part of eastern Himalayas in North Bengal from GPS measurements

Within the 2500 km stretch of the Himalayas, a narrow window between longitudes 88.185°E and 88.936°E in the frontal Himalayas in North Bengal, crisscrossed by several active fault traces, presents an interesting region for crustal deformation study. We have estimated velocities of 8 GPS stations located in this area and the accumulating strain rate by two different methods. A total shortening of 11.1 ±1.5 mm yr^?1 is occurring across a set of four E–W running faults: Gorubathan, Matiali, Chalsa and Baradighi. The strain rate becomes higher in the NE part of the network, reaching ?(0.25 ± 0.12) μstrain yr^?1 with azimuth 21°. A statistically significant extension of 10.9 ± 1.6 mm yr^?1 is estimated across the Gish transverse fault with a maximum strain rate of 0.36 ± 0.08 μstrain yr^?1 with azimuth 103°. The accumulating strain will be probably released through future earthquakes.