Effects of sedimentary layer on earthquake source modeling from geodetic inversion
Weiwen Chen1, Sidao Ni2, Shengji Wei3, Zhenjie Wang1, Jun Xie1
1 Mengcheng National Geophysical Observatory, University of Science and Technology of China, Hefei 230026, China 2 CAS Key Laboratory of Geodynamical Geodesy, Institute of Geodesy and Geophysics, Wuhan 430077, China 3 Seismological Laboratory, California Institute of Technology, Pasadena CA 91125, USA
Effects of sedimentary layer on earthquake source modeling from geodetic inversion
Weiwen Chen1, Sidao Ni2, Shengji Wei3, Zhenjie Wang1, Jun Xie1
1 Mengcheng National Geophysical Observatory, University of Science and Technology of China, Hefei 230026, China 2 CAS Key Laboratory of Geodynamical Geodesy, Institute of Geodesy and Geophysics, Wuhan 430077, China 3 Seismological Laboratory, California Institute of Technology, Pasadena CA 91125, USA
摘要Ground deformation as observed with GPS or InSAR has been broadly inverted in constraining source parameter of earthquakes. However, for earthquakes occurring beneath sedimentary basins, the very slow sub-surface shear velocity (vS, down to 200 m/s) may cause substantial bias to earthquake source inversion if simple crustal models are used. For Bohai basin, Sichuan basin and rock-sites, we test effects of sub-surface shear velocity structure on ground deformation, and find that up to a factor of 2 overestimate of seismic moment could be generated by the basin structures. Therefore, the very slow sub-surface velocity has to be taken into account before accurate source inversion can be applied.
Abstract：Ground deformation as observed with GPS or InSAR has been broadly inverted in constraining source parameter of earthquakes. However, for earthquakes occurring beneath sedimentary basins, the very slow sub-surface shear velocity (vS, down to 200 m/s) may cause substantial bias to earthquake source inversion if simple crustal models are used. For Bohai basin, Sichuan basin and rock-sites, we test effects of sub-surface shear velocity structure on ground deformation, and find that up to a factor of 2 overestimate of seismic moment could be generated by the basin structures. Therefore, the very slow sub-surface velocity has to be taken into account before accurate source inversion can be applied.
基金资助:National Natural Science Foundation of China (Nos. 40821160549 and 41074032), Chinese Academy of Sciences fund (No. KZCX2-YW-116-1) and Joint Seismological Science Foundation of China (200808078)
通讯作者:
Sidao Ni
E-mail: sdni@whigg.ac.cn
引用本文:
Weiwen Chen, Sidao Ni, Shengji Wei, Zhenjie Wang, Jun Xie. Effects of sedimentary layer on earthquake source modeling from geodetic inversion[J]. 《地震学报》英文版, 2011, 24(2): 221-227.
Weiwen Chen, Sidao Ni, Shengji Wei, Zhenjie Wang, Jun Xie. Effects of sedimentary layer on earthquake source modeling from geodetic inversion. Earthquake Science, 2011, 24(2): 221-227.
