利用GRACE重力和重力梯度变化估计2012年苏门答腊地震断层参数

doi:10.6038/cjg2019M0600

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (6049 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要 2012年4月11日苏门答腊北部附近海域发生M_W=8.6地震，国际上采用不同数据获得了该地震的断层滑动模型，但断层走滑性质存在较大差异.卫星重力GRACE（Gravity Recovery and Climate Experiment）观测覆盖震中区域，可以提供很好的断层参数估计约束.本文采用GRACE月重力场模型数据提取了此次地震同震重力和重力梯度变化，表明了北向分量的优越性.并与断层模型理论计算结果进行了比较，分析了T_xx（北-北向重力梯度）分量对断层参数的敏感性，以及基于粒子群算法以及Okubo位错模型反演了该地震断层参数.结果表明GRACE观测到的同震重力梯度变化在空间形态分布上与断层模型模拟结果符合较好，但振幅差异较大.重力和重力梯度的北向分量可以很好地压制条带误差，其中g_N（北向重力变化）和T_xx的误差最小，其次是T_xz（北-上向重力梯度），误差最大和对条带误差抑制效果最差的是T_xy（北-东向重力梯度）.T_xx对断层的深度不敏感，对其余断层参数较敏感.基于GRACE反演得到的断层的走向角为113.63°，倾角为89.99°，滑移角为175.26°，平均滑移量为28.18 m，相应的矩震为8.71级，且此次地震的走滑性质为右旋走滑.

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章
	郑增记
	金双根
	范丽红

关键词 ： GRACE, 粒子群算法, 苏门答腊地震, 断层参数

Abstract：The M_W=8.6 earthquakes occurred on 11 April 2012 and ruptured off the west coast of northern Sumatra. The fault slip models of the earthquake were estimated from different data, but have large differences in the strike-slip nature of faults. GRACE-derived co-seismic gravity changes cover the epicenter area, which can provide good constraint on the fault parameters inversion. In this paper, co-seismic gravity and gradient changes of the 2012 Sumatra earthquake are extracted from GRACE time-variable gravity field and the superiority of the northward component is presented. The theoretical calculation results of the fault model are compared with the GRACE and the sensitivity of the T_xx (north-to-north gravity gradient) to the fault parameters is analyzed. Finally, the fault parameters of the earthquake are retrieved based on the particle swarm optimization (PSO) algorithm and the Okubo dislocation model. The results show that the GRACE-observed co-seismic gravity and gravity gradient changes are in good agreement with the model-estimated results in spatial pattern, but have difference in amplitudes. The strip errors can be substantially suppressed by the north components of gravity and gravity gradients changes, where the noise level of g_N (north gravity change) and T_xx are the lowest, followed by T_xz (north-to-up gravity gradient) and the worst is the T_xy (north-to-east gravity gradient). The T_xx is not sensitive to the depth of the fault, but sensitive to other fault parameters. The GRACE-inverted strike angle, dip angle, rake angle and average slip magnitude of the earthquake are 113.63°, 89.99°, 175.26° and 28.18 m, respectively, indicating a moment-magnitude M_W=8.71. In addition, the GRACE-inverted rake angle shows that the earthquake is dominated by the right-lateral strike-slip.

Key words： GRACE PSO algorithm Sumatra earthquake Fault parameters

收稿日期: 2018-10-14

PACS:

P228

基金资助:国家重点研发计划项目课题（2018YFC0603502），中国地震局监测、预报、科研三结合课题（3JH-201901088），中国科学院西部青年学者项目（Y916YRa701）联合资助.

通讯作者: 金双根,研究员,博士生导师,主要从事卫星导航与大地测量学研究.E-mail:sgjin@shao.ac.cn E-mail: sgjin@shao.ac.cn

作者简介: 郑增记,男,1989年生,工程师,在读博士生,主要从事卫星重力与地震研究.E-mail:zhengzengji@shao.ac.cn

链接本文:

http://www.geophy.cn//CN/10.6038/cjg2019M0600 或 http://www.geophy.cn//CN/Y2019/V62/I11/4129

Cambiotti G, Bordoni A, Sabadini R, et al. 2011. GRACE gravity data help constraining seismic models of the 2004 Sumatran earthquake. Journal of Geophysical Research, 116:B10403, doi:10.1029/2010JB007848.
Cambiotti G, Sabadini R. 2013. Gravitational seismology retrieving Centroid-Moment-Tensor solution of the 2011 Tohoku earthquake. Journal of Geophysical Research:Solid Earth, 118(1):183-194, doi:10.1029/2012jb009555.
Carroll D L. 1996. Chemical laser modeling with genetic algorithms. AIAA Journal, 34(2):338-346, doi:10.2514/3.13069.
Cheng M K, Tapley B D. 2004. Variations in the Earth's oblateness during the past 28 years. Journal of Geophysical Research, 109:B09402, doi:10.1029/2004jb003028.
Dai C L, Shum C K, Wang R J, et al. 2014. Improved constraints on seismic source parameters of the 2011 Tohoku earthquake from GRACE gravity and gravity gradient changes. Geophysical Research Letters, 41(6):1929-1936, doi:10.1002/2013GL059178.
Dai C L, Shum C K, Guo J Y, et al. 2016. Improved source parameter constraints for five undersea earthquakes from north component of GRACE gravity and gravity gradient change measurements. Earth and Planetary Science Letters, 443:118-128, doi:10.1016/j.epsl.2016.03.025.
Delescluse M, Chamot-Rooke N, Cattin R, et al. 2012. April 2012 intra-oceanic seismicity off Sumatra boosted by the Banda-Aceh megathrust. Nature, 490(7419):240-244, doi:10.1038/nature11520.
de Linage C, Rivera L, Hinderer J, et al. 2009. Separation of coseismic and postseismic gravity changes for the 2004 Sumatra-Andaman earthquake from 4.6 yr of GRACE observations and modelling of the coseismic change by normal-modes summation. Geophysical Journal International, 176(3):695-714, doi:10.1111/j.1365-246X.2008.04025.x.
Han S C, Sauber J, Luthcke S. 2010. Regional gravity decrease after the 2010 Maule (Chile) earthquake indicates large-scale mass redistribution. Geophysical Research Letters, 37(23):L23307, doi:10.1029/2010GL045449.
Han S C, Sauber J, Riva R. 2011. Contribution of satellite gravimetry to understanding seismic source processes of the 2011 Tohoku-Oki earthquake. Geophysical Research Letters, 38(24):L24312, doi:10.1029/2011GL049975.
Han S C, Riva R, Sauber J, et al. 2013. Source parameter inversion for recent great earthquakes from a decade-long observation of global gravity fields. Journal of Geophysical Research:Solid Earth, 118(3):1240-1267, doi:10.1002/jgrb.50116.
Hanks T C, Kanamori H. 1979. A moment magnitude scale. Journal of Geophysical Research, 84(B5):2348-2350.
Hayes G. 2012. Preliminary Result of the Apr 11, 2012 M_W8.6 Earthquake Off the West Coast of Northern Sumatra. https://earthquake.usgs.gov/earthquakes/eventpage/official20120411083836720_20/finite-fault.
Heiskanen W A, Moritz H. 1967. Physical geodesy. Bulletin Géodésique, 86(1):491-492.
Ingber L. 1993. Simulated annealing:Practice versus theory. Mathematical & Computer Modelling, 18(11):29-57.
Jin S G, Zhang L J, Tapley B D. 2011. The understanding of length-of-day variations from satellite gravity and laser ranging measurements. Geophysical Journal International, 184(2):651-660.
Kennedy J, Eberhart R. 1995. Particle swarm optimization.//International Conference on Neural Networks. Perth, WA, Australia:IEEE, 1942-1948.
Li J. 2011. Detection of coseismic changes associated with large earthquakes by gravity gradient Changes from GRACE[Ph. D. thesis] (in Chinese). Wuhan:Wuhan University.
Li J, Shen W B. 2011. Investigation of the co-seismic gravity field variations caused by the 2004 Sumatra-Andaman earthquake using monthly GRACE data. Journal of Earth Science, 22(2):280-291, doi:10.1007/s12583-011-0181-x.
Martínez J L F, Gonzalo E G, Álvarez J P F, et al. 2010. PSO:A powerful algorithm to solve geophysical inverse problems:Application to a 1D-DC resistivity case. Journal of Applied Geophysics, 71(1):13-25, doi:10.1016/j.jappgeo.2010.02.001.
McGuire J J, Beroza G C. 2012. A rogue earthquake off Sumatra. Science, 336(6085):1118-1119, doi:10.1126/science.1223983.
Meng L, Ampuero J P, Stock J, et al. 2012. Earthquake in a maze:compressional rupture branching during the 2012 M_W8.6 Sumatra earthquake. Science, 337(6095):724-726, doi:10.1126/science.1224030.
Okubo S. 1992. Gravity and potential changes due to shear and tensile faults in a half-space. Journal of Geophysical Research:Solid Earth, 97(B5):7137-7144, doi:10.1029/92JB00178.
Petrovskaya M S, Vershkov A N. 2007. Non-singular expressions for the gravity gradients in the local north-oriented and orbital reference frames. Journal of Geodesy, 81(2):171-171, doi:10.1007/s00190-006-0087-z.
Shao G F, Li X Y, Ji C. 2012[2013-08-19]. Preliminary Result of the Apr 11, 2012 Mw 8.64 sumatra Earthquake. http://www.geol.ucsb.edu/faculty/ji/big_earthquakes/2012/04/10/sumatra.html.
Sun W K, Okubo S. 2004. Coseismic deformations detectable by satellite gravity missions:A case study of Alaska (1964, 2002) and Hokkaido (2003) earthquakes in the spectral domain. Journal of Geophysical Research:Solid Earth, 109(B4):B04405, doi:10.1029/2003jb002554.
Sun W K, Okubo S, Fu G Y, et al. 2009. General formulations of global co-seismic deformations caused by an arbitrary dislocation in a spherically symmetric earth model-applicable to deformed earth surface and space-fixed point. Geophysical Journal International, 177(3):817-833, doi:10.1111/j.1365-246X.2009.04113.x.
Swenson S, Wahr J. 2002. Methods for inferring regional surface-mass anomalies from Gravity Recovery and Climate Experiment (GRACE) measurements of time-variable gravity. Journal of Geophysical Research:Solid Earth, 107(B9):2193, doi:10.1029/2001JB000576.
Swenson S, Chambers D, Wahr J. 2008. Estimating geocenter variations from a combination of GRACE and ocean model output. Journal of Geophysical Research, 113:B08410, doi:10.1029/2007JB005338.
Wang L, Shum C K, Jekeli C. 2012. Gravitational gradient changes following the 2004 December 26 Sumatra-Andaman Earthquake inferred from GRACE. Geophysical Journal International, 191(3):1109-1118, doi:10.1111/j.1365-246X.2012.05674.x.
Wei S J. 2012[2013-07-01]. April/11/2012 (M_W8.6), Sumatra. Source Models of Large Earthquakes. http://www.tectonics.caltech.edu/slip_history/2012_Sumatra/index.html.
Wieczorek M A, Simons F J. 2005. Localized spectral analysis on the sphere. Geophysical Journal International, 162(3):655-675, doi:10.1111/j.1365-246X.2005.02687.x.
Yadav R K, Kundu B, Gahalaut K, et al. 2013. Coseismic offsets due to the 11 April 2012 Indian Ocean earthquakes (M_W8.6 and 8.2) derived from GPS measurements. Geophysical Research Letters, 40(13):3389-3393, doi:10.1002/grl.50601.
Yue H, Lay T, Koper K D. 2012. En échelon and orthogonal fault ruptures of the 11 April 2012 great intraplate earthquakes. Nature, 490(7419):245-249, doi:10.1038/nature11492.
Zhang G Q, Fu G Y, Zhou X, et al. 2015. Retrieve post-seismic gravity changes induced by Sumatra earthquake (M_W9.3) based on the viscoelastic dislocation theory. Chinese Journal of Geophysics (in Chinese), 58(5):1654-1665, doi:10.6038/cjg20150517.
Zheng W, Xu H Z, Zhong M, et al. 2010. Efficient and rapid estimation of the accuracy of future GRACE Follow-On Earth's gravitational field using the analytic method. Chinese Journal of Geophysics (in Chinese), 53(4):796-806, doi:10.3969/j.issn.0001-5733.2010.04.004.
Zheng W, Xu H Z, Zhong M, et al. 2014. Research progress in satellite gravity gradiometry recovery. Journal of Geodesy and Geodynamics (in Chinese), 34(4):1-8.
Zheng W, Yan J G, Li Z W. 2017. Reviews on deep space satellite gravity measurement mission. Journal of Deep Space Exploration (in Chinese), 4(1):3-13.
Zheng Z J, Jin S G, Fan L H. 2018. Co-seismic deformation following the 2007 Bengkulu earthquake constrained by GRACE and GPS observations. Physics of the Earth and Planetary Interiors, 280:20-31, doi:10.1016/j.pepi.2018.04.009.
Zhou X, Sun W K, Fu G Y. 2011. Gravity satellite GRACE detects coseismic gravity changes caused by 2010 Chile M_W8.8 earthquake. Chinese Journal of Geophysics (in Chinese), 54(7):1745-1749, doi:10.3969/j.issn.0001-5733.2011.07.007.
附中文参考文献
李进. 2011. 基于GRACE时变重力梯度探测大地震的同震变化[博士论文]. 武汉:武汉大学.
张国庆, 付广裕, 周新等. 2015. 利用震后黏弹性位错理论研究苏门答腊地震(M_W9.3)的震后重力变化. 地球物理学报, 58(5):1654-1665, doi:10.6038/cjg20150517.
郑伟, 许厚泽, 钟敏等. 2010. 利用解析法有效快速估计将来GRACE Follow-On地球重力场的精度. 地球物理学报, 53(4):796-806, doi:10.3969/j.issn.0001-5733.2010.04.004.
郑伟, 许厚泽, 钟敏等. 2014. 卫星重力梯度反演研究进展. 大地测量与地球动力学, 34(4):1-8.
郑伟, 鄢建国, 李钊伟. 2017. 深空卫星重力测量计划研究综述. 深空探测学报, 4(1):3-13.
周新, 孙文科, 付广裕. 2011. 重力卫星GRACE检测出2010年智利Mw8.8地震的同震重力变化. 地球物理学报, 54(7):1745-1749, doi:10.3969/j.issn.0001-5733.2011.07.007.