2013年芦山M_S7.0地震的震前及临震应变异常
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摘要
距离芦山地震震中70km的姑咱地震台YRY四分量钻孔应变仪2013年4月16—19日记录到8次幅度达到十倍固体潮幅的张性应变阶跃,这在该仪器6年多运行期间尚属首次.这些应变异常与芦山地震在时间、空间上相关;应变异常的主压应力方向与震前宝兴水压致裂地应力测量主压应力方向相近,并与震前5个月中长达3个月的应变异常主压应力方向一致;应变阶跃起始与远震震波同时到达.综上认为,4月16—19日的应变异常有可能是芦山地震发震断裂在破裂错动前地层蠕滑的反映.
The YRY four-component borehole strainmeter of Guzan Station, 70 km away from the epicenter of Lushan earthquake, recorded eight tensile strain steps with the range of ten times of tidal amplitude on April 16—19, which has never happened over the past 6 years’observation. The strain anomalies are related to Lushan earthquake both in time and space. The principal stress direction deduced by the abnormal strain, similar to that of in-situ stress measurement by hydrofracturing at Baoxing before the earthquake, is in accordance with 3-months-records during the five months before the Lushan earthquake. Some of the strain steps occurred when teleseismic waves arrived. As mentioned above, we presume the strain anomalies of April 16—19 probably reflect the strata creeping before the rupturing of the Lushan earthquake generating fault.
引文
池顺良,池毅,邓涛,廖成旺,唐小林,池亮.2009.从5·12汶川地震前后分量应变仪观测到的应变异常看建设密集应变观测网的必要性[J].国际地震动态,(1):1--12.
    丰成君.2013.宝兴钻孔地应力绝对测量与相对监测结果与芦山7.0级地震[EB/OL].科学网.[2013-05-06].http:∥blog.sciencenet.cn/blog-921682-687097.html
    刘琦,张晶.2011.S变换在汶川地震前后应变变化分析中的应用[J].大地测量与地球动力学,31(4):6--9.
    邱泽华,石耀霖.2003.地震造成远距离应力阶变的观测实例[J].中国科学:D辑,33(增刊):60--64.
    邱泽华,张宝红,池顺良,唐磊,宋茉.2010.汶川地震前姑咱台观测的异常应变变化[J].中国科学:地球科学,40(8):1031--1039.
    邱泽华,周龙寿.2009.用超限率分析法研究汶川地震的前兆应变变化[J].大地测量与地球动力学,29(4):1--9.
    王梅,季爱东,徐长鹏,王鹏.2013.环境干扰事件引起的“形变异常变化”[J].国际地震动态,(1):15--19.
    张国民,傅征祥,桂燮泰.2001.地震预报引论[M].北京:科学出版社:366--378.

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