Retrieve post-seismic gravity changes induced by sumatra earthquake (m(w)9. 3) based on the viscoelastic dislocation theory
文献类型：期刊论文
| 作者 | Zhang Guo-Qing1; Fu Guang-Yu1,2,3; Zhou Xin2,4; Xu Chang-Yi2 |
| 刊名 | Chinese journal of geophysics-chinese edition
 |
| 出版日期 | 2015-05-01 |
| 卷号 | 58期号:5页码:1654-1665 |
| 关键词 | Spherical dislocation theory Grace Sumatra earthquake (m(w)9. 3) Gravity changes Viscosity |
| ISSN号 | 0001-5733 |
| DOI | 10.6038/cjg20150517 |
| 通讯作者 | Fu guang-yu(fugy@seis.ac.cn) |
| 英文摘要 | The grace (gravity recovery and climate experiment) mission has continually provided the data of temporal variability of the global gravity after its launch. several coseismic gravity changes have been successfully retrieved by the grace mission. the visco-elastic dislocation theory is used to study the co- and post-seismic deformations. in this paper, we study the post-seismic gravity changes due to the 2004 sumatra earthquake (m(w)9. 3) based on the visco-elastic spherical dislocation theory and the grace data, and then analyze the viscosity of the mantle and horizontal difference at this area. we adopt the rl05 data provided by ut/csr (center for space research, university of texas), and the data spans from january 2003 to december 2014. we replaced the earth's oblateness values (c-20) with those from satellite laser ranging because of their poor accuracy. after the de-correlation filter using polynomials of degree 3 for coefficients with orders 6 or higher to alleviate longitudinal stripes and the gaussian smoothing with averaging radius of 350 km to reduce short wavelength noises, we obtain the post-seismic gravity changes due to the 2004 sumatra earthquake (m(w)9. 3) based on the difference method and time series of two points respectively located on the hanging side and the heading side. we adopt the visco-elastic spherical dislocation theory to validate the grace-derived result. we first use the integration of the finite fault models to solve the problem of large errors in the near-field computation using the visco-elastic spherical dislocation theory, and comparing the modified results with the results of elastic spherical dislocation theory. after that, we retrieve post-seismic gravity changes induced by the earthquake. the result shows that the peak of the gravity changes is from -8. 3 to 4. 6 mu gal in the period of 2004-2005 based on the grace, which is consistent with the result derived by the elastic spherical dislocation theory in the spatial distribution and the magnitude. based on the spatial distribution of the gravity changes and the analysis of time series, we find that the rate of the post-seismic gravity change at the heading side is 0. 55 mu gal/yr and the rate is 0. 16 mu gal/yr on the other side, which demonstrates that the viscosity of the two sides of the fault is different. the differences of coseismic vertical displacement and gravity changes based on the modified visco-elastic theory are respectively 0. 06% and 0. 1%, compared with those derived from the elastic spherical dislocation theory. we also analyze the green functions of the vertical displacement and gravity changes at the source depth of 32 km in two different periods of 0 similar to 0. 7 years and 0 similar to 7 years, which demonstrate that we have successfully solved the problem of large errors in the near-field computation using the visco-elastic spherical dislocation theory. based on the corrected method, we simulate the post-seismic gravity changes due to the 2004 sumatra earthquake (m(w)9. 3), finding that only when the viscosity of the heading side is 1 x 10(18) pa . s and the viscosity of the hanging side is 8 x 10(18) pa . s, the simulating results are consistent with the grace-derived results in the spatial distribution and the magnitude. based on the theory results, we find that the rate of the post-seismic gravity changes at the heading side is 0. 52 mu gal/yr and the rate of the post-seismic gravity changes at the hanging side is 0. 12 mu gal/yr. comparing the observing results with the simulating results, it demonstrates that the viscosity of the mantle at the sumatra region is laterally inhomogeneous. the viscosity at the left side (the heading side) of the fault is smaller than the one at the right side (the hanging side) of the fault, and the viscosity is respectively 1 x 10(18) pa . s and 8 x 10(18) pa . s. |
| WOS关键词 | SPHERICAL EARTH ; ANDAMAN EARTHQUAKE ; POINT DISLOCATIONS ; GRAVITATIONAL DEFORMATION ; INTERNAL DISLOCATIONS ; RELAXATION THEORY ; 2004 DECEMBER ; HALF-SPACE ; MODEL ; SURFACE |
| WOS研究方向 | Geochemistry & Geophysics |
| WOS类目 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000355639800017 |
| 出版者 | SCIENCE PRESS |
| URI标识 | http://www.irgrid.ac.cn/handle/1471x/2376676 |
| 专题 | 中国科学院大学 |
| 通讯作者 | Fu Guang-Yu |
| 作者单位 | 1.CEA, Key Lab Earthquake Predict, Inst Earthquake Sci, Beijing 100036, Peoples R China 2.Chinese Acad Sci, Key Lab Computat Geodynam, Grad Univ, Beijing 100049, Peoples R China 3.State Key Lab Geodesy & Earths Dynam, Wuhan 430077, Peoples R China 4.Univ Tokyo, Earthquake Res Inst, Tokyo 1130032, Japan |
| 推荐引用方式 GB/T 7714 | Zhang Guo-Qing,Fu Guang-Yu,Zhou Xin,et al. Retrieve post-seismic gravity changes induced by sumatra earthquake (m(w)9. 3) based on the viscoelastic dislocation theory[J]. Chinese journal of geophysics-chinese edition,2015,58(5):1654-1665. |
| APA | Zhang Guo-Qing,Fu Guang-Yu,Zhou Xin,&Xu Chang-Yi.(2015).Retrieve post-seismic gravity changes induced by sumatra earthquake (m(w)9. 3) based on the viscoelastic dislocation theory.Chinese journal of geophysics-chinese edition,58(5),1654-1665. |
| MLA | Zhang Guo-Qing,et al."Retrieve post-seismic gravity changes induced by sumatra earthquake (m(w)9. 3) based on the viscoelastic dislocation theory".Chinese journal of geophysics-chinese edition 58.5(2015):1654-1665. |
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来源：中国科学院大学
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