EPP

地球与行星物理

ISSN  2096-3955

CN  10-1502/P

Preliminary result for the rupture process of Nov.13, 2017, Mw7.3 earthquake at Iran-Iraq border
WeiMin Wang, JianKun He, JinLai Hao, ZhenXing Yao
doi: 10.26464/epp2018008
Keywords: Iran-Iraq border earthquake, source process, waveform inversion
Exact local refinement using Fourier interpolation for nonuniform-grid modeling
JinHai Zhang, ZhenXing Yao
doi: 10.26464/epp2017008
Numerical solver using a uniform grid is popular due to its simplicity and low computational cost, but would be unfeasible in the presence of tiny structures in large-scale media. It is necessary to use a nonuniform grid, where upsampling the wavefield from the coarse grid to the fine grid is essential for reducing artifacts. In this paper, we suggest a local refinement scheme using the Fourier interpolation, which is superior to traditional interpolation methods since it is theoretically exact if the input wavefield is band limited. Traditional interpolation methods would fail at high upsampling ratios (say 50); in contrast, our scheme still works well in the same situations, and the upsampling ratio can be any positive integer. A high upsampling ratio allows us to greatly reduce the computational burden and memory demand in the presence of tiny structures and large-scale models, especially for 3D cases.
Keywords: local refinement, varying grid, tiny structures, fourier interpolation, nonuniform grid
Seismic characteristics of the 15 February 2013 bolide explosion in Chelyabinsk, Russia
Zhi Wei, LianFeng Zhao, XiaoBi Xie, JinLai Hao, ZhenXing Yao
doi: 10.26464/epp2018039
The seismological characteristics of the 15 February 2013 Chelyabinsk bolide explosion are investigated based on seismograms recorded at 50 stations with epicentral distances ranging from 229 to 4324 km. By using 8–25 s vertical-component Rayleigh waveforms, we obtain a surface-wave magnitude of 4.17±0.31 for this event. According to the relationship among the Rayleigh-wave magnitude, burst height and explosive yield, the explosion yield is estimated to be 686 kt. Using a single-force source to fit the observed Rayleigh waveforms, we obtain a single force of 1.03×1012 N, which is equivalent to the impact from the shock wave generated by the bolide explosion.
Keywords: Rayleigh-wave magnitude, yield estimation, focal mechanism, the 15 February 2013 Chelyabinsk bolide
Preliminary results for the rupture process of Jan. 10, 2018, Mw7.6 earthquake at east of Great Swan Island, Honduras
WeiMin Wang, JinLai Hao, ZhenXing Yao
doi: 10.26464/epp2018010
Keywords: east of Great Swan Island earthquake, source process, waveform inversion

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