Estimation of the source process of the 2015 Gorkha, Nepal, earthquake and simulation of long-period ground motions in the Kathmandu basin using a one-dimensional basin structure model

• Published in: Earth, planets, and space Vol. 68; no. 1; p. 1
• Main Authors: Kubo, Hisahiko, Dhakal, Yadab P., Suzuki, Wataru, Kunugi, Takashi, Aoi, Shin, Fujiwara, Hiroyuki
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 05-02-2016; Springer Nature B.V
• Subjects: 4. Seismology; Earth and Environmental Science; Earth Sciences; Earthquake and Himalayan Studies: First Results; Geology; Geophysics/Geodesy; Letter; Nepal; The 2015 Gorkha; The 2015 Gorkha earthquake; Long-period ground motions in the Kathmandu basin; Source rupture process; Waveform simulation; Joint source inversion
• ISSN: 1880-5981; 1880-5981
• DOI: 10.1186/s40623-016-0393-5

The source rupture process of the 2015 Gorkha, Nepal, earthquake was estimated by the joint kinematic source inversion with near-field waveforms, teleseismic waveforms, and geodetic data. The estimated seismic moment and maximum slip are 7.5 × 10
20
 Nm (
M
w
7.9) and 7.3 m, respectively. The total source duration is approximately 50 s. The derived source model has a unilateral rupture toward the east and a large-slip area north of Kathmandu with the maximum slip. Using the estimated source model together with a one-dimensional (1-D) velocity basin structure model, long-period (> 4 s) ground motions were simulated at a site located in the Kathmandu basin, where strong ground motions with predominant components in a 4–5s period were observed during the 2015 Gorkha earthquake. This simulation demonstrated that the major features of the observed waveforms can be reproduced by our source model and the 1-D basin structure model.