Title | Source characteristics of the 2015 Mw 7.8 Gorkha (Nepal) earthquake and its Mw 7.2 aftershock from space geodesy |
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Author | Feng, W ; Lindsey,
E; Barbot, S; Samsonov, S V ; Dai, K; Li, P; Li, Z; Almeida, R;
Chen, J; Xu, X |
Source | Tectonophysics vol. 712-713, 2017 p. 747-758, https://doi.org/10.1016/j.tecto.2016.02.029 |
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Year | 2017 |
Alt Series | Natural Resources Canada, Contribution Series 20170192 |
Publisher | Elsevier BV |
Document | serial |
Lang. | English |
Media | paper; on-line; digital |
File format | pdf |
Area | Gorkha; Kathmandu; Nepal |
Lat/Long WENS | 84.0000 88.0000 29.0000 26.0000 |
Subjects | earthquakes; remote sensing; health hazards; faults, slip; modelling; ALOS-2; Sentinel-1a; The Main Frontal Thrust fault (MFT); RADARSAT-2 |
Illustrations | location maps; satellite images; tables; plots |
Released | 2016 03 02 |
Abstract | On April 25, 2015, a destructive MW 7.8 earthquake struck the capital of Nepal, Kathmandu, killing more than 8800 people and destroying numerous historical structures. We analyze six coseismic
interferograms from several satellites (ALOS-2, Sentinel-1 A, and RADARSAT-2), as well as three-dimensional displacements at six GPS stations to investigate fault structure and slip distribution of the Gorkha earthquake. Using a layered crustal
structure, the best-fit slip model shows that the preferred dip angle of the mainshock fault is 6 ± 3.5° and the major slip is concentrated within depths of 8 - 15 km. The maximum slip of ~ 6.0 m occurs at a depth of 11 km, 70 km south east of the
epicenter. The coseismic rupture extends ~ 150 km eastward of the epicentre with a cumulative geodetic moment of 7.8 × 1020 Nm, equivalent to an earthquake of MW 7.84. We also investigate the MW 7.2 aftershock on 12 May 2015 using another three
postseismic interferograms from ALOS2, RADARSAT-2, and Sentinel-1 A. The InSAR-based best-fit slip model of the largest aftershock implies that its major slip is next to the eastern lower end of the mainshock rupture with a similar maximum slip of ~
6 m at a depth of ~ 13 km. This study generates various coseismic geodetic measurements to determine the source parameters of the MW 7.8 Gorkha earthquake and 12 May MW 7.2 afershock, providing an additional chance to understand the local fault
structure and slip extent. |
GEOSCAN ID | 305951 |
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