Evidence of low velocity layers at the top and bottom of the Mantle Transition Zone (MTZ) below the Uttarakhand Himalaya, India.

The Mantle Transition Zone (MTZ) beneath the Uttarakhand Himalaya has been modelled using Common Conversion Point (CCP) stacking and depth-migration of radial P-receiver functions. In the Uttarakhand Himalaya region, the depths of the 410-km discontinuity (d410) and the 660-km discontinuity (d660) are estimated to be approximately 406 ± 8 km and 659 ± 10 km, respectively. Additionally, the thickness of the mantle transition zone (MTZ) is modelled to be 255 ± 7 km.

Evidence of structural segmentation of the Uttarakhand Himalaya and its implications for earthquake hazard.

The earthquake hazard associated with the Main Himalayan Thrust (MHT) is a critical issue for India and its neighbouring countries in the north. We used data from a dense seismic network in Uttarakhand, India, to model the lateral variations in the depths of MHT (2-6% drop in V at 12-21 km depths), Moho (a sharp increase in V (by ~ 0.5-0.

Evidence of secular variation in Archean crust formation in the Eastern Indian Shield.

Understanding the dominant crustal accretion model in any Archean craton is the key to understanding the dominant geodynamic process responsible for early crust formation during the Hadean (> 4.0 Ga) and Archaean (4.0-2.

Modelling the seismic potential of the Indo-Burman megathrust.

The Indo-Burman arc is the boundary between the India and Burma plates, north of the Sumatra-Andaman subduction zone. The existence of active subduction in the Indo-Burman arc is a debatable issue because the Indian plate converges very obliquely beneath the Burma plate. Recent GPS measurements in Bangladesh, Myanmar, and northeast India indicate 13-17 mm/y of plate convergence along a shallow dipping megathrust while most of the strike-slip motion occurs on several steep faults, consistent with patterns of strain partitioning at subduction zones.

Detection and potential early warning of catastrophic flow events with regional seismic networks.

Early warning is a critical potential tool for mitigating the impacts of large mass wasting and flood events, a major hazard in the Himalaya. We used data from a dense seismic network in Uttarakhand, India, to detect and track a fatal rockslide to mass flow to flood cascade and examine the potential for regional networks to provide early warning for extreme flow events. Detection limits of the 7 February 2021 event depend on the nature of the active process and on the anthropogenic and environmental seismic noise levels at each station.

Modelling of crustal composition and Moho depths and their Implications toward seismogenesis in the Kumaon-Garhwal Himalaya.

We image the lateral variations in the Moho depths and average crustal composition across the Kumaon-Garhwal (KG) Himalaya, through the H-K stacking of 1400 radial PRFs from 42 three-component broadband stations. The modelled Moho depth, average crustal Vp/Vs, and Poisson's ratio estimates vary from 28.3 to 52.