A Comparative Account of Terrestrial and Satellite Based Potential Field Data for Regional Tectonic/Structural Interpretation and Crustal Scale Modeling With Reference to the Indian Region

In the recent past, several global geopotential models (GGM) were made available in the public domain but all these models have variable spatial resolution which is not always readily apparent on visual inspection. In the present study, evolution tests based on the statistical estimates, spectral analysis and Image enhancement filters have been performed to assess the spatial resolution and quality of Earth Gravitational models (EGM2008, GOCE, DTU13 and SSV23.1) and crustal magnetic field model (EMAG2) over the Indian shield and its surrounding offshore regions. Our study reveals that EGM2008 and satellite altimetry (DTU13 and SSV23.1) derived gravity models provide remarkable accuracies and wavelength resolutions (<19 km for EGM 2008; <4 km for DTU13 and SSV23.1) equal to the terrestrial (ground/shipboard gravity) measurements in the continental and oceanic regions respectively. It is also evident from both 2-d forward modeling and spectral analysis that the accuracy of GOCE derived global gravity models lies at longer wavelengths (i.e.,>125 km) which is useful for the delineating the subsurface density heterogeneities and deep crustal features such as suture/contact zones. Further image enhancement interpretation of these global geopotential models resolve the major structural trends, and provide new information on the crustal architecture.