Using GNSS data,the estimation model for GNSS multiscale strain field was established based on spherical wavelet. The key technologies for wavelet center location, wavelet scale choices and regularization parameter calculation were discussed in detail. For further testing the correctness of the model, the simulated data in locked fault areas was generated according to negative dislocation theory. With spherical wavelet model, the strain field in locked strike-slip fault areas was estimated,and the results agreed well with the characteristics of actual crustal deformation. Meanwhile, the experiments on crustal deformation anomaly detection with multiscale strain field were completed. The results showed that the small fault deformation of 50 km appeared obviously in the small scale(8th scale) stain field, but there wasn't signals in the large scale (4 to 7 scale). The large fault deformation of 150 km only showed a part of information in the small scale (8th scale) stain field, but showed more completely and clearly in the large scale(4 to 7 scale).So it's concluded that crustal deformation of different spatial coverage scope embody in the different scales strain field, and the small scale strain field have the ability to detect regional deformation anomaly.
[1] 江在森,马宗晋,张希,等.GPS初步结果揭示的中国大陆水平应变场与构造变形[J].地球物理学报,2003,46(3):352-358.JIANG Zaisen,MA Zongjin,ZHANG Xi,et al.Horizontal Strain Field and Tectonic Deformation of China Mainland Revealed by Preliminary GPS Result[J].Chinese Journal of Geophysics,2003,46(3):352-358.
[2] 徐克科,伍吉仓,吴伟伟.基于GNSS时空数据的瞬态无震蠕滑信息检测[J].地球物理学报,2015,58(7):2330-2338.XU Keke,WU Jicang,WU Weiwei.Detection of Transient Aseismic Slip of Signals from GNSS Spatial-temporal Data[J].Chinese Journal of Geophysics,2015,58(7):2330-2338.
[3] 张培震,邓起东,张竹琪,等.中国大陆的活动断裂、地震灾害及其动力过程[J].中国科学:地球科学,2013,43(10):1607-1620.ZHANG Peizhen,DENG Qidong,ZHANG Zhuqi,et al.Active Faults,Earthquake Hazards and Associated Geodynamic Processed in Continental China[J].Scientia Sinica Terrae,2013,43(10):1607-1620.
[4] 姜卫平,周晓慧,刘经南,等.青藏高原地壳运动与应变的GPS监测研究[J].测绘学报,2008,37(3):285-292.JIANG Weiping,ZHOU Xiaohui,LIU Jingnan,et al.Present-day Crustal Movement and Strain Rate in the Qinghai-Tibetan Plateau from GPS Data[J].Acta Geodaetica et Cartographica Sinica,2008,37(3):285-292.
[5] 杜方,闻学泽,张培震.鲜水河断裂带炉霍段的震后滑动与形变[J].地球物理学报,2010,53(10):2355-2366.DU Fang,WEN Xueze,ZHANG Peizhen.Post-seismic Slip and Deformation on the Luhuo Segment of the Xianshuihe Fault Zone[J].Chinese Journal of Geophysics,2010,53(10):2355-2366
[6] 赵丽华,杨元喜,王庆良.考虑区域构造特征的地壳形变分析拟合推估模型[J].测绘学报,2011,40(4):435-441.ZHAO Lihua,YANG Yuanxi,WANG Qingliang.Collocation Model Based on Regional Tectonic Features in Crustal Deformation Analysis[J].Acta Geodaetica et Cartographica Sinica,2011,40(4):435-441.
[7] HOLSCHNEIDER M,CHAMBODUT A,MANDEA M.From Global to Regional Analysis of the Magnetic Field on the Sphere Using Wavelet Frames[J].Physics of the Earth and Planetary Interiors,2003,135(2-3):107-124.
[8] HOLSCHNEIDER M,IGLEWSKA-NOWAK I.Poisson Wavelets on the Sphere[J].Journal of Fourier Analysis and Applications,2007,13(4):405-419.
[9] CHAMBODUT A,PANET I,MANDEA M,et al.Wavelet Frames:An Alternative to Spherical Harmonic Representation of Potential Fields[J].Geophysical Journal International,2005,163(3):875-899.
[10] BOGDANOVA I,VANDERGHEYNST P,ANTOINE J P,et al.Stereographic Wavelet Frames on the Sphere[J].Applied and Computational Harmonic Analysis,2005,19(2):223-252.
[11] TAPE C,MUSé P,SIMONS M,et al.Multiscale Estimation of GPS Velocity Fields[J].Geophysical Journal International,2009,179(2):945-971.
[12] 程鹏飞,文汉江,孙罗庆,等.中国大陆GPS速度场的球面小波模型及多尺度特征分析[J].测绘学报,2015,44(10):1063-1070.DOI:10.11947/j.AGCS.2015.20140141.CHENG Pengfei,WEN Hanjiang,SUN Luoqing,et al.The Spherical Wavelet Model and Multiscale Analysis of Characteristics of GPS Velocity Fields in Mainland China[J].Acta Geodaetica et Cartographica Sinica,2015,44(10):1063-1070.DOI:10.11947/j.AGCS.2015.20140141.
[13] KENNER H.Geodesic Math and How to Use It[M].Berkeley:University of California Press,1976.
[14] GOLUB G H,HEATH M,WAHBA G.Generalized Cross-Validation as a Method for Choosing a Good Ridge Parameter[J].Technometrics,1979,21(2):215-223.
[15] 刘序俨,季颖锋,黄声明,等.地形变应变张量矩阵的不变量分析[J].大地测量与地球动力学,2011,31(4):66-70.LIU Xuyan,JI Yingfeng,HUANG Shengming,et al.Analysis of Invariants in Strain Tensor Matrixes of Crustal Deformation[J].Journal of Geodesy and Geodynamics,2011,31(4):66-70.
[16] 伍吉仓,许厚泽,丁晓利,等.台湾集集大地震断层非均匀滑动分布的反演[J].测绘学报,2002,31(S1):34-38.WU Jicang,XU Houze,DING Xiaoli,et al.Inversion of Variable Fault Slip of Taiwan Chi-Chi Earthquake[J].Acta Geodaetica et Cartographica Sinica,2002,31(S1):34-38.
[17] 伍吉仓,邓康伟,陈永奇.板块内部层状负位错模型及其反演[J].武汉大学学报(信息科学版),2003,28(6):671-674.WU Jicang,DENG Kangwei,CHEN Yongqi.Negative Dislocation Layer for Intraplate Tectonic Movements and Inversion[J].Geomatics and Information Science of Wuhan University,2003,28(6):671-674.
[18] STEKETEE J A.On Volterra's Dislocations in a Semi-infinite Elastic Medium[J].Canadian Journal of Physics,1958,36(2):192-205.
[19] OKADA Y.Surface Deformation Due to Shear and Tensile Faults in a Half-space[J].Bulletin of the Seismological Society of America,1985,75(4):1135-1154.
[20] 徐克科,伍吉仓,王成.利用GNSS位移时空序列进行断层无震蠕滑特征分析[J].武汉大学学报(信息科学版),2015,40(9):1247-1252.XU Keke,WU Jicang,WANG Cheng.Analysis of Fault Aseismic Slip Feature Based on GNSS Displacement Time-space Series[J].Geomatics and Information Science of Wuhan University,2015,40(9):1247-1252.