Inaugural Lectures by Fellows/Associates

Isostasy and Strength of Continental Lithosphere – Insights from Studies over Indian Plate

In recent discussions, it has been suggested that the crust alone contributes to the long-term strength of the continental lithosphere – referred as ‘Crème Brûlée Model’, contrary to the widely accepted ‘Jelly Sandwich Model’. Integrated strength or Effective Elastic Thickness (EET) of the lithosphere is often determined through isostatic analyses, employing gravity anomalies. However, estimates of EET are sometime biased to the utilized methodologies. To address these two issues – estimation of EET and model of strength of continental lithosphere, we have methodically recorded and analysed gravity and topographic data using physics based model in conjunction with other geophysical observations over different geological terrains of Indian Tectonic Plate. We argue with our studies that both the mentioned models compete to each other, depending upon the underlying lithospheric properties. This has added a novel perception on the global debate over the model of continental lithospheric strength and isostatic compensation mechanism.