Research Projects

Variations in the lithospheric structure is a first-order feature of the Earth that provide valuable insights to unravel the geological processes associated with plate tectonics (Fischer et al., 2010; Artemieva, 2011). Therefore, several geophysical observations for example seismic, gravity, geodetic, electromagnetic and geological samples were examined in order to better constraints the structure of the lithosphere and distinct interfaces within the lithosphere system such as Moho discontinuity and mid-lithospheric discontinuities. The significant variation in lithospheric structure is noticed during the break-up of continental lithosphere and sometimes large volume of continental mantle lithosphere are exhumed to ocean floor (Mutter et al., 1982; Whitmarsh et al., 2001; Huismans and Beaumont, 2011). During the subduction process, the characteristics of subducting oceanic lithosphere (e.g., age of ocean floor, chemical composition, flexural rigidity, obliquity, and sediment thickness) control the state of stress, dynamics and hazard potential of subducting plate (Korenaga, 2007; Arnulf et al., 2022). The strength of the oceanic lithosphere reduced by 40-65% due to bending (change in the curvature) at subduction zone and hence the configuration of bending plate affects the state of stress and entrainment of water into the seismogenic zone (Ranero et al., 2003; Naif et al., 2015). Therefore, mapping the architecture of LAB shed the light on the geological processes involved in continental breakup and subduction zone. The offshore Bengal Basin is a small region where transition of continental rifting to seafloor spreading is preserved on the land and also oceanic lithosphere is subducting beneath the Burma (Mitchell, 1981; Ni et al., 1989; Kumar et al., 2015; Talwani et al., 2016; Ismaiel et al., 2019; Krishna et al., 2022). In the Bangladesh region, presence of seaward dipping reflectors is inferred and have been interpreted as response of volcanic rifting in this area around 120 Ma. However, variation in lithospheric thickness from unstretched continental domain to oceanic domain remain unexplored. Across the Indo-Burma range, extensive geophysical studies have been carried out to understand the structure of the lithosphere system and deformation associated with collision and subduction of Indian plate beneath the Burma plate. The lithospheric thickness is a crucial parameter to affects the nature of subduction beneath the Indo-Burma Ranges, however, the architecture of the lithosphere remains less understood due to sparse seismometer stations in the region. Thus, imaging the variation in lithospheric thickness and Moho depth over the Indo-Burma range is much needed now. In the proposed proposal, we will be delineating the lateral variations in Moho depth and lithospheric thickness using the gravity (USGS and GSI data) and P and S receiver functions analysis (Bangladesh-India-Myanmar Array network) over the Bengal basin and Indo-Burma ranges.