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Imaging the Moho and the Main Himalayan Thrust in Western Nepal With Receiver Functions
Author(s) -
Subedi Shiba,
Hetényi György,
Vergne Jérôme,
Bollinger Laurent,
LyonCaen Hélène,
Farra Véronique,
Adhikari Lok Bijaya,
Gupta Ratna Mani
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl080911
Subject(s) - geology , foothills , seismology , receiver function , thrust , lithosphere , tectonics , geography , cartography , physics , thermodynamics
The crustal structure of Western Nepal is studied for the first time by performing receiver function analysis on teleseismic waveforms recorded at 16 seismic stations. The Moho geometry is imaged as it deepens from ~40‐km depth beneath the foothills and the Lesser Himalaya to ~58‐km depth beneath the Higher Himalayan range. A midcrustal low‐velocity zone is detected at ~15‐km depth along ~55‐km horizontal distance and is interpreted as the signature of fluids expelled from rocks descending in the footwall of the Main Himalayan Thrust. Our new image allows structural comparison of the Moho and of the Main Himalayan Thrust geometry along‐strike of the Himalayas and documents long‐wavelength lateral variations. The general crustal architecture observed on our images resembles that of Central Nepal; therefore, Western Nepal is also expected to be able to host large (M W > 8) megathrust earthquakes, as the 1505 CE event.