Activity 2B – Geometry and rheological assessment of MHT, lithospheric flexuring – implications toward seismogenesis; deep earth processes
This research activity primarily focuses on the delineation of structure and rheology of the crust and upper mantle to understand the surface manifestations of subsurface processes and genesis of earthquakes in the Himalaya. Assessment of geometry and rheology of the Main Himalaya Thrust (MHT), existence and extent of mid-crustal ramp structure, intra-crustal low-velocity zones (if any) are important features with regard to addressing the seismicity, seismotectonics and geodynamic evolution. A state-of-the-art passive seismological and Magneto-Telluric experiments are being carried out for imaging 2D and 3D subsurface structures beneath the defined transects in the northwest, and northeastern parts of the Himalaya. Several data analysis methodologies like Seismic Tomography: Ambient Noise tomography, Surface wave tomography, Body wave tomography, and Receiver Function analysis are being applied for obtaining high-resolution images. This research activity also emphasizes integrated interpretation of seismological and magnetotelluric data with the geological investigation for robust estimation of subsurface features and their linkage to seismic activity in the Himalayan regions. The institute has already established the permanent and campaign-mode broadband seismic networks in the Northwest and Northeast Himalaya, Ladakh, and Indo-Gangetic Plains to carry out the passive seismological study.