| Autor: |
Mishra, Sushrat, Borah, Kajaljyoti, Saha, Gokul Kumar |
| Zdroj: |
Journal of Earth System Science; Dec2024, Vol. 133 Issue 4, p1-19, 19p |
| Abstrakt: |
The ongoing convergence between the Indian and Eurasian plates has formed the Himalayan mountain range, which has its highest peak at Mount Everest. A study of the detailed crustal shear velocity structure beneath the Mount Everest region that is present at the boundary between Nepal and Tibet will improve our understanding of the mountain-building process and plate dynamics in this collision zone. In this study, 250 earthquake data have been used to compute receiver functions at three seismic stations (NNAMC, EVN and RBSH) operated in the study region. Receiver functions have been modelled through different approaches, namely H-κ stacking, Neighbourhood Algorithm and joint inversion. The results reveal a thicker crust (~52–58 km) with average shear velocity (Vs) ~3.35–3.46 km/s and felsic-to-intermediate composition (Vp/Vs: 1.722–1.744) in the study region. We also observed a low Vs in the lower crust (~3.6–3.7 km/s) with upper mantle Vs ~4.3–4.6 km/s. The ratio of mountain surface elevation to crustal root is found to be between ~0.14 and 0.2, which is well correlated with the younger orogen (<100 Myr). At ~20–24 km depth, a mid-crustal low-velocity zone is present beneath the study region, which could be due to the presence of partial melt at that depth. Research highlights: Inversion of receiver function and surface wave dispersion data reveals a thicker crust (~52–58 km) with average shear velocity (Vs) ~3.35–3.46 km/s and felsic-to-intermediate composition (Vp/Vs: 1.72–1.74) beneath the Mount Everest region. Low Vs observed in the lower crust (~3.6–3.7 km/s). R-value (Ratio of mountain surface relief to crustal root) is ~0.14 to 0.2, well correlated with the younger orogens. A prominent Low-Velocity Zone (LVZ) associated with the Main Himalayan Thrust (MHT) is observed at ~20–24 km depth. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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