A Short Walk through Gravity Studies at CSIR-NGRI, India

Abstract

The Earth’s gravity field measurements and their applications for resource exploration and geodynamic studies form an important part of geophysical studies initiated at the CSIR-National Geophysical Research Institute (CSIR-NGRI) since its inception. Finite Element analysis for regional-residual separation, scaling attributes of the source distribution, together with the mathematical formulation to density distribution in sedimentary basins have transformed the interpretation of gravity data. Collection, collation, and standardization of terrestrial gravity data have led to the compilation of the Gravity Map Series of India. Analyses of these data with contemporary computational technologies help in deciphering better-resolved density models under different parts of the Indian plate. These studies have provided well-constrained models of active and ancient continental collision zones, magmatic underplating beneath large igneous provinces, an integrated lithospheric density structure of Dharwar and Singhbhum cratons, the evolution of passive continental margins of India, and estimation of the effective strength of the Indian lithosphere. The studies on temporal gravity changes from terrestrial and satellite observations are also carried out to infer the redistribution of mass in the earthquake-prone regions and water storage variabilities over India. Recently, moving-platform gravity gradiometry has been introduced by the Institute in India. The gravity studies have continued to be a vital component of an integrated geophysical approach adopted by CSIR-NGRI for shallow and deep earth explorations.