We use data from 24 broadband seismographs located south of the Eastern Himalayan plate boundary system to investigate the crustal structure beneath Northeast India. P wave receiver function analysis reveals felsic continental crust beneath the Brahmaputra Valley, Shillong Plateau and Mikir Hills, and mafic thinned passive margin transitional crust (basement layer) beneath the Bengal Basin. Within the continental crust, the central Shillong Plateau and Mikir Hills have the thinnest crust (30 ± 2 km) with similar velocity structure, suggesting a unified origin and uplift history. North of the plateau and Mikir Hills the crustal thickness increases sharply by 8–10 km and is modeled by ∼30∘ north dipping Moho flexure. South of the plateau, across the ∼1 km topographic relief of the Dawki Fault, the crustal thickness increases abruptly by 12–13 km and is modeled by downfaulting of the plateau crust, overlain by 13–14 km thick sedimentary layer/rocks of the Bengal Basin. Farther south, beneath central Bengal Basin, the basement layer is thinner (20–22 km) and has higher Vs (∼4.1 km s−1) indicating a transitional crystalline crust, overlain by the thickest sedimentary layer/rocks (18–20 km). Our models suggest that the uplift of the Shillong Plateau occurred by thrust faulting on the reactivated Dawki Fault, a continent margin paleorift fault, and subsequent back thrusting on the south dipping Oldham Fault, in response to flexural loading of the Eastern Himalaya. Our estimated Dawki Fault offset combined with timing of surface uplift of the plateau reveals a reasonable match between long‐term uplift and convergence rate across the Dawki Fault with present‐day GPS velocities.

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Crustal configuration beneath the Satluj valley region of the northwest Himalaya has been studied with the help of receiver function analysis of teleseismic earthquakes recorded by 18 broadband seismological stations. These stations were located on diverse geotectonic units from the Himalayan foreland basin in the south to the Tethyan Himalaya (TH) in the north. A gentle north dipping structure of the Main Himalayan Thrust (MHT) is imaged between the Sub and Higher Himalaya in contrast to the reported ramp structure of the MHT beneath the Garhwal and Nepal Himalaya. The ramp structure is, however, identified further north, beyond the South Tibetan Detachment in Satluj valley. The depth of the MHT varies from ~16 to 27 km across the Sub, Lesser, and Higher Himalaya, and it increases to ~38 km beneath the TH forming a ramp. This is significantly a different structure of the MHT beneath the Satluj valley, which is attributed to the effect of underthrusting Delhi‐Hardwar Ridge, a transverse structure to the Himalayan arc. Conspicuously, no strong or large earthquake is observed during 1964–2015 in this segment of the Himalayan Seismic Belt. The RF modeling, on the other hand, shows ~44 km crustal thickness beneath the Himalayan Frontal Thrust (HFT), and it gradually increases to ~62 km beneath the TH. Low shear wave velocity (~0.8–1.8 km s−1) is observed in the uppermost 3–4 km of the crust beneath the stations near the HFT, which may be the effect of the sedimentary column of the Indo‐Gangetic Plain.