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Abstract

The stability of the plate interior region is better understood with a robust estimation of the rotation pole. Significant earthquakes in intraplate areas have the potential to deform plate interiors severely. So, a precise estimation of the rotation pole is the key to understanding the internal deformation. Early plate motion models and GPS measurements indicate that the Indian plate is moving in the NE direction at a rate of ~5cm/year. Several previous studies suggest that the internal deformation of the Indian plate is ~1-2mm/yr, which is very low, so the plate behaves as a single rigid block. The hypotheses of the two-plate model had also been tested using only a few GPS sites. Using >60 GPS sites within the plate, we estimate Euler pole at 51.99±0.22°N, 2.83±0.83°E with an angular velocity of 0.5205±0.002°/myr. The estimated internal deformation is ~1mm/yr corresponding to strain rate of ~1-3 nanostrain/yr. We also observed that the North and South blocks of the Indian plate have different behaviour of seasonal variation in GPS time series, with the North block showing uplift and the South block showing subsidence. This may be related to the depletion and recharge of groundwater level in the North and South block, respectively. We are also looking for the segmentation of the Indian plate along the Narmada-Son lineament.