印尼地震对我国川滇地区地壳水平活动的影响  

EFFECT OF INDONESIA EARTHQUAKE ON HORIZONTAL CRUSTAL MOVEMENT IN SICHUAN-YUNNAN REGION

作　　者：杨国华[1] 江在森[2] 王敏[2] 张祖胜[1] 刘广余[1] 韩月萍[1] 丁平[3] 龚平 

机构地区：[1]中国地震局第一监测中心,天津300180 [2]中国地震局地震预测研究所,北京100036 [3]中国地震局第二监测中心,西安710054 [4]湖北省地震局,武汉430071

出　　处：《大地测量与地球动力学》2006年第1期9-14,20,共7页Journal of Geodesy and Geodynamics

基　　金：财政部项目:南北地震带震情跟踪;中国地震局项目:强地震中期预测新技术;物理基础及其应用研究

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 MsS. 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.

关 键 词：印尼地震 川滇地区 影响 GPS 地壳水平活动 

分 类 号：P315.72[天文地球—地震学]