| Title | Depth varying rupture properties during the 2015 Mw 7.8 Gorkha (Nepal) earthquake
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| Author | Yue, H; Simons, M; Duputel, Z; Jiang, J; Fielding, E; Liang, C; Owen, S; Moore, A; Riel, B; Ampuero, JP; Samsonov, S V |
| Source | Tectonophysics 2016, 11 pages, https://doi.org/10.1016/j.tecto.2016.07.005 |
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| Year | 2016 |
| Alt Series | Natural Resources Canada, Contribution Series 20170212 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Area | Kathmandu; Gorkha; Nepal |
| Lat/Long WENS | 84.0000 87.0000 29.0000 27.0000 |
| Subjects | structural geology; earthquakes; remote sensing; radar imagery; faults, thrust; modelling; faults, slip; structural analyses |
| Illustrations | satellite images; graphs; location maps; models |
| Released | 2017 09 01 |
| Abstract | On April 25th 2015, the Mw 7.8 Gorkha (Nepal) earthquake ruptured a portion of the Main Himalayan Thrust underlying Kathmandu and surrounding regions. We develop kinematic slip models of the Gorkha
earthquake using both a regularized multi-time-window (MTW) approach and an unsmoothed Bayesian formulation, constrained by static and high rate GPS observations, synthetic aperture radar (SAR) offset images, interferometric SAR (InSAR), and
teleseismic body wave records. These models indicate that Kathmandu is located near the updip limit of fault slip and approximately 20 km south of the centroid of fault slip. Fault slip propagated unilaterally along-strike in an ESE direction for
approximately 140 km with a 60 km cross-strike extent. The deeper portions of the fault are characterized by a larger ratio of high frequency (0.03 - 0.2 Hz) to low frequency slip than the shallower portions. From both the MTW and Bayesian results,
we can resolve depth variations in slip characteristics, with higher slip roughness, higher rupture velocity, longer rise time and higher complexity of subfault source time functions in the deeper extents of the rupture. The depth varying nature of
rupture characteristics suggests that the up-dip portions are characterized by relatively continuous rupture, while the down-dip portions may be better characterized by a cascaded rupture. The rupture behavior and the tectonic setting indicate that
the earthquake may have ruptured both fully seismically locked and a deeper transitional portions of the collision interface, analogous to what has been seen in major subduction zone earthquakes. |
| GEOSCAN ID | 305986 |
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