Comparative analysis of the structural pattern over the Indian Ocean basins using EIGEN6C4 Bouguer gravity data

Abstract

The Indian Ocean witnessed numerous seismic and tectonic activities, making the region an intricate seismotectonic and seismo-genesis potential zone. The high-resolution global satellite-derived Bouguer Gravity Anomaly (BGA) data was used for comparative analysis of the structural patterns of six Indian Ocean basins. THETA (TA) edge enhancement and upward continuation techniques were used to study the Indian Ocean crustal structure by mapping both short and longwave lineaments. Rayleigh wave group velocity (RWGV) tomography at different time periods indicates pseudo depths of ∼30 km and ∼50 km are suitable for the upward continuation (UC) of BGA that perhaps lead to understanding different contrasting boundaries in their TA map. The UC of the BGA was generated at 60 km and 100 km for highlighting different lineaments/structures/contrasting geological boundaries at the depths of about 30 km and 50 km. The orientation of TA lineaments shows NNE-SSW, NE-SW, and EES-WWN structural trends. The statistical analysis of the lineaments shows that the Mid-Indian Basin constitutes the highest values of lineament number, lineament density (LD), circular variance (CV) and circular standard deviation (CSD), indicating a slow tectonic deformation over a long period. The Somalian Basin shows the minimum lineament number and lowest LD with high values of CV and CSD, indicating a relatively stable tectonic set-up compared to other Indian Ocean basins. The Arabian and Bay of Bengal basins offer relatively low lineament statistics than the Mid-Indian, Wharton and Madagascar basins, indicating frequent tectonic activity.