铁岭地震台SS-Y型伸缩仪2018年6月起出现NS分量的持续拉张和EW分量的小幅压性变化,经初步分析,发现仪器工作状态良好,并排除各类干扰因素。采用三点线性平滑滤波,对NS、EW分量进行趋势项、周期项提取处理,发现自2018年6月起,NS分量趋势性拉张且年变增加,EW分量趋势性压缩且年变减小,与以往相比,趋势和年变周期变化特征差异性较大,结合同一山洞的水管倾斜仪和垂直摆倾斜仪同时段产生同步转折变化及历史震例,分析认为,铁岭SS-Y型洞体应变NS分量变化为震前异常的可能性较大,后续应跟踪分析该异常的趋势性走向变化。
According to the analysis of the continuous tension of the NS component and the small amplitude change of the EW component of the SS-Y telescopic instrument of Tieling Seismic Station after June 2018, preliminary analysis of the instrument in good working condition and no one is disturbing and the surrounding environment exists, then, the three-point linear smoothing filter is used to analyze the trend items and periodic items of the two component data of NS and EW. It is found that from June 2018, NS trended tensile and annual change, the EW component trend compression year becomes smaller, the trend characteristics of two directions and annual variation period change characteristics are larger than the previous ones, combined with the same cave water pipe tilt meter synchronous transition changes occur at the same time as the vertical pendulum tilting instrument. The historical case analysis shows that the NS component of the Tieling SS-Y type cavity is more likely to be a precursor anomaly, and the trending trend of the anomaly is followed by follow-up analysis.
2019,40(6): 111-117 收稿日期:2019-09-28
DOI:10.3969/j.issn.1003-3246.2019.06.016
基金项目:中国地震局震情跟踪青年课题(项目编号:2018010224);辽宁省地震局青年基金(项目编号:LZ201908)
作者简介:翟丽娜(1986-),女,工程师,硕士,主要从事地壳形变与地震预测研究工作。E-mail:529436296@qq.com
*通讯作者:焦明若(1963-),男,研究员,主要从事地震预测研究工作。E-mail:359203477@qq.com
参考文献:
辽宁省地震局. 辽宁省地震监测志[M]. 北京:地震出版社,2004.
吕宠吾,孙亚强,杜为民,等. SS-Y型短基线伸缩仪及其标定装置[J]. 地壳形变与地震,2001,21(3):82-88.
吕宠吾,杨江. 差分式伸缩仪[J]. 大地测量与地球动力学,2009,29(3):145-147.
牛安福,张凌空,闫伟,吉平. 汶川地震近震源区地形变短期前兆现象的解析[J]. 地震,2012,32(2):52-63.
吴翼麟,李平,陈光齐,等. 以倾斜固体潮探测地壳内的应变积累[J]. 中国地震,1992,8(4):62-67.
翟丽娜,贾晓东,孔祥瑞,等. 营口台SQ-70模拟水平摆倾斜异常分析[J]. 防灾减灾学报,2017,33(2):1-7.
翟丽娜,贾晓东,孔祥瑞,等. 丹东台水管倾斜短期异常分析[J]. 防灾减灾学报,2018,34(3):6-12.
中国地震局监测预报司. 地形变测量[M]. 北京:地震出版社,2008:74.
Mjachkin V I, Brace W F, Sobolev G A, Dieterich J H. Two models for earthquake forerunners[J]. Pure and Applied Geophysics, 1975, 113(1):169-181.
Nur A. Dilatancy, pore fluids, and premonitory variations of tS/tP travel times[J]. Bull Seismol Soc Am, 1972, 62(5):1 217-1 222.
Rummel F, Alheid H J, Frohn C. Dilatancy and fracture induced velocity changes in rock and their relation to frictional sliding[J]. Pure and Applied Geophysics, 1978, 116(4/5):743-764.