Plate motion predictability using Hurst exponent applied to the Maitri-antarctica GPS network

The Global Positioning System (GPS) data collected during years 1997–2007 at Maitri along with the International GNSS Service (IGS) stations viz. Casey, Davis, Yaragadee, Tidbinbilla, Seychelles, Coco, Diego Garcia, Kerguelen and Hartbeesthoek in and around Indian Ocean were processed using Bernese. 4.2 software. The baseline length and their changes were estimated and spectral analysis was carried out subsequently. The value of the Hurst exponent, as estimated from the slope of spectral fall-off of each time series of baseline length, was used to interpret the characteristics of the plate motions in the region. The Hurst exponent is found to be 0.65 (>0.5) for the baseline length between stations Kerguelen and Coco clearly showing a constant increasing trend of the changes in baseline length. The time series of baseline lengths between stations Kerguelen and Diego Garcia; and Tidbinbilla and Yaragadee shows an increasing trend and the Hurst exponent is close to 0.5. This may suggest that the diffuse plate boundary zone and the Australian plate are moving away from the Antarctican plate. The baseline length between Kerguelen and Davis, Casey, Maitri and Seychelles is less than 0.5, which indicates that the baseline length of these stations shows a decreasing trend.