Strain accumulation studies between Antarctica and India through geodetic tying of two continents from continuous GPS measurements

404-411The geodynamical and crustal deformation processes in the south of Indian peninsula between India and Antarctica had been examined. Two global networks (IND and ANT) that geodetically connect the two continents, the IGS Station at Diego Garcia (DGAR), as a common station between the two networks, had been chosen for the study. The data from 1997 to 2005 were used for above purpose. The present study elucidates the increase in baseline lengths between Kerguelen in Antarctic plate and other stations. Whereas the baseline lengths shorten between HYDE in Indian plate and other common stations. The GPS velocity fields of Maitri and other IGS stations in and around Antarctica in different plates relative to Kerguelen show the departure from rigid plate behaviour. This is in a manner consistent with the mapped intra plate stress field, deformations and seismicity in the region. The analysis shows lengthening of baselines for sites Yaragadee (YAR1) and Tidbinbilla (TID2) in Australian plate; and Seychelles (SEY1) and COCO in Indian plate. The above lengthening is at the rates of 5.3 cm/yr, 3.8 cm/yr, 5.6mm/yr and 5.5 cm/yr respectively. The station Hartebeesthoek (HRAO) in South African plate shows a trend of minimal shortening at the rate of 1.7 mm/yr. The velocities with uncertainties (±1σ) are in good agreement with geodetic and geologic models. The present results are with precision of approximately 3-4 mm (North), 5-6 mm (East), and 10-12 mm (vertical). The accumulation of elastic strain, provide new information on the direction and rate of Indian plate motion, and intra plate seismicity of the Indian Ocean. The estimated elastic strain accumulation shows an increasing trend of 1.27 x 10⁻⁸ yr⁻¹