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Evidence of interseismic coupling variations along the Bhutan Himalayan arc from new GPS data
Author(s) -
Marechal Anais,
Mazzotti Stephane,
Cattin Rodolphe,
Cazes Gael,
Vernant Philippe,
Drukpa Dowchu,
Thinley Kinzang,
Tarayoun Alizia,
Le RouxMallouf Romain,
Thapa Bal Bahadur,
Pelgay Phuntsho,
Gyeltshen Jampel,
Doerflinger Erik,
Gautier Stéphanie
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 - 10.1002/2016gl071163
Subject(s) - geology , seismology , decoupling (probability) , coupling (piping) , geodesy , global positioning system , mechanical engineering , telecommunications , control engineering , computer science , engineering
Although the first‐order pattern of present‐day deformation is relatively well resolved across the Himalayas, irregular data coverage limits detailed analyses of spatial variations of interseismic coupling. We provide the first GPS velocity field for the Bhutan Himalaya. Combined with published data, these observations show strong east‐west variations in coupling between central and eastern Bhutan. In contrast with previous estimations of first‐order uniform interseismic coupling along the Himalayan arc, we identify significant lateral variations: In western and central Bhutan, the fully coupled segment is 135–155 km wide with an abrupt downdip transition, whereas in eastern Bhutan the fully coupled segment is 100–120 km wide and is limited updip and downdip by partially creeping segments. This is the first observation of decoupling on the upper ramp along the Himalayan arc, with important implications for large earthquake surface rupture and seismic hazard.