基于经验模态分解的潮汐观测长趋势分析
|
摘要
运用经验模态分解方法,提取定点倾斜和应变固体潮观测数据的长趋势变化。通过对在震中周边600km范围内的地震台站的倾斜潮汐长趋势变化进行倾斜矢量分析,发现在2010年4月14日青海玉树MS7.1地震前,距震中31km的玉树台倾斜矢量曲线出现"打结"现象。同时,对该区域内的应变潮汐长趋势变化进行面应变分析,发现处于玉树—甘孜断裂带两端的格尔木台和甘孜台的面应变在玉树地震发生前半年出现了异常转折,这种变化可能反应了该断裂带在地震前的面应变的变化。经验模态分解方法可用于认识某个区域内的倾斜、应变状态。
On Apr.14,2010,an MS7.1 earthquake occurred in Yushu,Qinghai.Using the Empirical Model Decomposition method,we analyzed the data of tilt earth tide and the data of strain earth tide from 6 stations(Yushu,Xiangcheng,Delingha,Huangyuan,Geermu,Ganzi)located within 600km from the Yushu earthquake's epicenter,to extract the long-trend variations of tilt earth tide and strain earth tide.Some abnormalities were found before the Yushu earthquake on the tilt vector map and plane strain map.The curves of tilt vector at Yushu Station which was only 31 km away from the epicenter quickly twisted before the Yushu earthquake.The curves of plane strain at Geermu Station and Ganzi Station which were located at both ends of the Yushu-Ganzi Fault changed their directions six months before the earthquake.This may reflect the Fault Zone's plane strain change before Yushu earthquake.
On Apr.14,2010,an MS7.1 earthquake occurred in Yushu,Qinghai.Using the Empirical Model Decomposition method,we analyzed the data of tilt earth tide and the data of strain earth tide from 6 stations(Yushu,Xiangcheng,Delingha,Huangyuan,Geermu,Ganzi)located within 600km from the Yushu earthquake's epicenter,to extract the long-trend variations of tilt earth tide and strain earth tide.Some abnormalities were found before the Yushu earthquake on the tilt vector map and plane strain map.The curves of tilt vector at Yushu Station which was only 31 km away from the epicenter quickly twisted before the Yushu earthquake.The curves of plane strain at Geermu Station and Ganzi Station which were located at both ends of the Yushu-Ganzi Fault changed their directions six months before the earthquake.This may reflect the Fault Zone's plane strain change before Yushu earthquake.
引文
何翔.1993.倾斜矢量图正常年变化破坏的机理研究[J].地壳形变与地震,13(1):62-68.
李永振.2010.利用主成分分析法研究东北地震活动异常[J].地震研究,33(2):164-169.
张雁滨,蒋骏,周翠屏.1996.地表潮汐线应变、剪应变与面应变观测的残差矢量及其震兆变化[J].地壳形变与地震,16(3):49-54.
张义平,李夕兵,左宇军.2008.爆破振动信号的HHT分析与应用[M].北京:冶金工业出版社.
Huang N E,Zhang S,Steven L,et al.1998.The empirical mode decompo-sition and the Hilbert spectrum for nonlinear and non-stationary time series analysis[C]//Proceedings of the Royal Society of London,Series A,454:903-995.
李永振.2010.利用主成分分析法研究东北地震活动异常[J].地震研究,33(2):164-169.
张雁滨,蒋骏,周翠屏.1996.地表潮汐线应变、剪应变与面应变观测的残差矢量及其震兆变化[J].地壳形变与地震,16(3):49-54.
张义平,李夕兵,左宇军.2008.爆破振动信号的HHT分析与应用[M].北京:冶金工业出版社.
Huang N E,Zhang S,Steven L,et al.1998.The empirical mode decompo-sition and the Hilbert spectrum for nonlinear and non-stationary time series analysis[C]//Proceedings of the Royal Society of London,Series A,454:903-995.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心