印尼地震对我国川滇地区地壳水平活动的影响
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摘要
2005年1~2月用GPS技术对中国川滇地区及中国南部进行了精密流动与连续监测,综合利用1999年、2001年和2004年的数据及GPS处理技术获取了2004年12月26日印尼苏门答腊地震(Ms8.7)对监测区所产生的同震水平位移场。由水平位移图可知,此次地震对川滇地区及其以东及中国南部地区的影响是显著的,其特征为对四川地区的影响相对较小,数值为数毫米,优势位移方向为西;对云南地区的影响较大,数值一般为10~20mm,变化趋势为“北小南大”,优势位移方向为西南。应变分析表明,此次地震对该区造成的区域应变非常突出,并且占主导地位,南北方向表现为整体拉伸,东西方向为“北张南压”,面应变除南缘为收缩外几乎整个区域为面膨胀,并呈现“北大南小”的变化特征,最大剪应变则恰好相反。由此反映的相对位移在该区南北端的差别接近20mm,与背景应变场的结果相比有很大的差异。另由拉萨、昆明和广州等连续监测站的结果可知,西藏地区没有受到显著的影响,西沙群岛和海南地区向西南位移了大约20mm,云南地区向西南位移了大约12mm,泸州及福建沿海地区没有明显的变化。
In Sichuan-Yunnan region and the southern part of China, a precise mobile and continuous monitoring is carried out with GPS technique from Jan. to Feb. in 2005. Integrated with the data observed in 1999, 2001 and 2004, the coseismic horizontal displacement of the monitoring area field caused by the %M%s8.7 Sumatera earthquake occurred on Dec.26, 2004 in Indonesia is surveyed with the GPS data processing technique. The horizontal displacement diagram shows that this earthquake affects significantly the Sichuan-Yunnan area and the east to it and the South China area. The effect on Sichuan region is relatively small with a magnitude of several mm and the dominant displacement direction of W. The effect on Yunnan region is larger with a general value of 10-20 mm and the variation of “smaller in the North and larger in the South”, and the dominant displacement direction of SW. The strain analysis shows that the regional strain associated with the earthquake is very prominent and dominant with an extension of the entire region in the NS direction and “the tension in the north and the compression in the south” in the EW direction. As to surface strain,it almost is opposite to the relative displacement between the south and north ends of the region is about 20 mm, which is much different from the result of background strain field. In addition, the strain results served of the continuous monitoring stations in Lhasa, Kunming, Guangzhou etc.,show that the effect on Tibetan region is not large; Xisha Qundao and Hainan region had moved about 20 mm to the southwest; Yunnan region had moved about 13 mm to the southwest; and Luzhou and Fujian coastal regions did not change obviously.
In Sichuan-Yunnan region and the southern part of China, a precise mobile and continuous monitoring is carried out with GPS technique from Jan. to Feb. in 2005. Integrated with the data observed in 1999, 2001 and 2004, the coseismic horizontal displacement of the monitoring area field caused by the %M%s8.7 Sumatera earthquake occurred on Dec.26, 2004 in Indonesia is surveyed with the GPS data processing technique. The horizontal displacement diagram shows that this earthquake affects significantly the Sichuan-Yunnan area and the east to it and the South China area. The effect on Sichuan region is relatively small with a magnitude of several mm and the dominant displacement direction of W. The effect on Yunnan region is larger with a general value of 10-20 mm and the variation of “smaller in the North and larger in the South”, and the dominant displacement direction of SW. The strain analysis shows that the regional strain associated with the earthquake is very prominent and dominant with an extension of the entire region in the NS direction and “the tension in the north and the compression in the south” in the EW direction. As to surface strain,it almost is opposite to the relative displacement between the south and north ends of the region is about 20 mm, which is much different from the result of background strain field. In addition, the strain results served of the continuous monitoring stations in Lhasa, Kunming, Guangzhou etc.,show that the effect on Tibetan region is not large; Xisha Qundao and Hainan region had moved about 20 mm to the southwest; Yunnan region had moved about 13 mm to the southwest; and Luzhou and Fujian coastal regions did not change obviously.
引文
1 李延兴,李智,张静华,等.中国大陆及周边地区的水平应变场[J].地球物理学报,2004,47(2):222~231.
1 Li Yanxing,Li Zhi,Zhang Jinghua,et al.Horizontal strain field in Chinese mainland and the surrounding are-as[J].Chinese Journal of Geophysics,2004.47(2):222-231.(in Chinese)
2 杨少敏,等.用双三次样条函数和GPS资料反演现今中国大陆构造形变场[J].大地测量与地球动力学,2002,22(1):68~75.
2 Yang Shaomin,et al.Contemporary horizontal tectonic deformation fields in China inversed form GPS observa-tions data[J].Journal of Geodesy and Geodynamics,2002,22(1):68-75.(in Chinese)
3 杨国华.水平形变场的函数描述与实现方法[J].地壳形变与地震,199212(1):46~51.
3 Yang Guohua.A description and realization of horizontal deformation field by the multi-kernel function[J].Crustal Deformation and Earthquake,199212(1):46-51.(in Chinese)
4 杨国华,王琪,王敏,等.云南地区现今地壳水平运动与变化特征[J].大地测量与地球动力学,2003,23(2):7~16.
4 Yang Guohua,Wang Qi,Wang Min,et al.Current hor-izontal crustal movement and deformation characteristics in Yunnan area[J].Journal of Geodesy and Geody nam-ics,2003,23(2):7-16.(in Chinese)
5 杨国华,韩月萍,王敏,等.中国大陆几个地震活动区的水平形变[J].大地测量与地球动力学,2003,23(3):42~49.
5 Yang Guohua,Han Yueping,Wang Min,et al.Hori-zontal deformationin several major seismically active are-as in Chinese mainland[J].Journal of Geodesy and Geo-dynamics,2003,23(3):42-49.(in Chinese)
6 张静华,李延兴,郭良迁,等.用GPS测量结果研究华北现今构造形变场[J].大地测量与地球动力学,2004,24(3):40~46.
6 Zhang Jinhua,Li Yanxing,Guo Liangqian,et al.Study on present-day deformation and strain filedin North Chi-na by use of GPS data[J].Journal of Geodesy and Geody namics,2004,24(3):40-46.(in Chinese)
7 石耀霖,朱守彪.利用GPS观测资料划分现今地壳活动块体的方法[J].大地测量与地球动力学,2004,24(2):1~5.
7 Shi Yaolin and Zhu Shoubiao.Method for division of present active crustal blocks by GPS survey data[J].Journal of Geodesy and Geodynamics,2004,24(3):1-5.(in Chinese)
1 Li Yanxing,Li Zhi,Zhang Jinghua,et al.Horizontal strain field in Chinese mainland and the surrounding are-as[J].Chinese Journal of Geophysics,2004.47(2):222-231.(in Chinese)
2 杨少敏,等.用双三次样条函数和GPS资料反演现今中国大陆构造形变场[J].大地测量与地球动力学,2002,22(1):68~75.
2 Yang Shaomin,et al.Contemporary horizontal tectonic deformation fields in China inversed form GPS observa-tions data[J].Journal of Geodesy and Geodynamics,2002,22(1):68-75.(in Chinese)
3 杨国华.水平形变场的函数描述与实现方法[J].地壳形变与地震,199212(1):46~51.
3 Yang Guohua.A description and realization of horizontal deformation field by the multi-kernel function[J].Crustal Deformation and Earthquake,199212(1):46-51.(in Chinese)
4 杨国华,王琪,王敏,等.云南地区现今地壳水平运动与变化特征[J].大地测量与地球动力学,2003,23(2):7~16.
4 Yang Guohua,Wang Qi,Wang Min,et al.Current hor-izontal crustal movement and deformation characteristics in Yunnan area[J].Journal of Geodesy and Geody nam-ics,2003,23(2):7-16.(in Chinese)
5 杨国华,韩月萍,王敏,等.中国大陆几个地震活动区的水平形变[J].大地测量与地球动力学,2003,23(3):42~49.
5 Yang Guohua,Han Yueping,Wang Min,et al.Hori-zontal deformationin several major seismically active are-as in Chinese mainland[J].Journal of Geodesy and Geo-dynamics,2003,23(3):42-49.(in Chinese)
6 张静华,李延兴,郭良迁,等.用GPS测量结果研究华北现今构造形变场[J].大地测量与地球动力学,2004,24(3):40~46.
6 Zhang Jinhua,Li Yanxing,Guo Liangqian,et al.Study on present-day deformation and strain filedin North Chi-na by use of GPS data[J].Journal of Geodesy and Geody namics,2004,24(3):40-46.(in Chinese)
7 石耀霖,朱守彪.利用GPS观测资料划分现今地壳活动块体的方法[J].大地测量与地球动力学,2004,24(2):1~5.
7 Shi Yaolin and Zhu Shoubiao.Method for division of present active crustal blocks by GPS survey data[J].Journal of Geodesy and Geodynamics,2004,24(3):1-5.(in Chinese)
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