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The 2015 Gorkha earthquake: A large event illuminating the Main Himalayan Thrust fault
Author(s) -
Duputel Zacharie,
Vergne Jérôme,
Rivera Luis,
Wittlinger Gérard,
Farra Véronique,
Hetényi György
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 - 10.1002/2016gl068083
Subject(s) - hypocenter , aftershock , geology , seismology , centroid , fault (geology) , moment tensor , shock (circulatory) , geodesy , foreshock , geometry , induced seismicity , medicine , oceanography , mathematics , deformation (meteorology)
The 2015 Gorkha earthquake sequence provides an outstanding opportunity to better characterize the geometry of the Main Himalayan Thrust (MHT). To overcome limitations due to unaccounted lateral heterogeneities, we perform Centroid Moment Tensor inversions in a 3‐D Earth model for the main shock and largest aftershocks. In parallel, we recompute S ‐to‐ P and P ‐to‐ S receiver functions from the Hi‐CLIMB data set. Inverted centroid locations fall within a low‐velocity zone at 10–15 km depth and corresponding to the subhorizontal portion of the MHT that ruptured during the Gorkha earthquake. North of the main shock hypocenter, receiver functions indicate a north dipping feature that likely corresponds to the midcrustal ramp connecting the flat portion to the deep part of the MHT. Our analysis of the main shock indicates that long‐period energy emanated updip of high‐frequency radiation sources previously inferred. This frequency‐dependent rupture process might be explained by different factors such as fault geometry and the presence of fluids.