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Faulting structure above the Main Himalayan Thrust as shown by relocated aftershocks of the 2015 M w 7.8 Gorkha, Nepal, earthquake
Author(s) -
Bai Ling,
Liu Hongbing,
Ritsema Jeroen,
Mori James,
Zhang Tianzhong,
Ishikawa Yuzo,
Li Guohui
Publication year - 2016
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 - 10.1002/2015gl066473
Subject(s) - aftershock , geology , seismology , hypocenter , thrust fault , main central thrust , compression (physics) , shock (circulatory) , intraplate earthquake , continental collision , fault (geology) , tectonics , subduction , induced seismicity , physics , medicine , thermodynamics
The 25 April 2015, M w 7.8 Gorkha, Nepal, earthquake ruptured a shallow section of the Indian‐Eurasian plate boundary by reverse faulting with NNE‐SSW compression, consistent with the direction of current Indian‐Eurasian continental collision. The Gorkha main shock and aftershocks were recorded by permanent global and regional arrays and by a temporary local broadband array near the China‐Nepal border deployed prior to the Gorkha main shock. We relocate 272 earthquakes with M w >3.5 by applying a multiscale double‐difference earthquake relocation technique to arrival times of direct and depth phases recorded globally and locally. We determine a well‐constrained depth of 18.5 km for the main shock hypocenter which places it on the Main Himalayan Thrust (MHT). Many of the aftershocks at shallower depths illuminate faulting structure in the hanging wall with dip angles that are steeper than the MHT. This system of thrust faults of the Lesser Himalaya may accommodate most of the elastic strain of the Himalayan orogeny.