地震前后断层测点群体活动的量化指标
|
摘要
地震前后,随着构造应力场的增强或减弱,断层测点群体偏离稳态变化的程度随之增大或减小;同时,由于震源体内外介质物性的差异,断层测点之间偏离稳态变化的差异性也随之增大或减小。基于这一事实,采用随机变量的数字指标,提出了一种反映断层群体活动的量化指标——断层活动强度及非均匀度。结合具体震例对青藏块体东北部、川滇地区的断层水准资料进行了计算,结果表明量化指标在地震前后一般会出现一个明显的增大或减小过程。
The degree that the swarm movement of measurement sites of cross-faults deviates from stability, increases or decreases along with strengthening or weakening of tectonic stress field before and after earthquake. At the same time, the difference of deviation from stability among the measurement sites increases or decreases due to the difference between internal and external medium characteristic of the source body.On the basis of the fact, a quantized index of swarm sites movement of faults——the average strongth and the non-homogeneity of fault movement with the numeric index of random variable is put forward.By calculating the vertical deformation data of cross-faults in Sichuan-Yunnan area and the northern margin of Qinghai-Tibet block,and comparatively studying some practical earthquake examples, the results are obtained: the quantized index increases or decreases obviously before and after earthquake.
The degree that the swarm movement of measurement sites of cross-faults deviates from stability, increases or decreases along with strengthening or weakening of tectonic stress field before and after earthquake. At the same time, the difference of deviation from stability among the measurement sites increases or decreases due to the difference between internal and external medium characteristic of the source body.On the basis of the fact, a quantized index of swarm sites movement of faults——the average strongth and the non-homogeneity of fault movement with the numeric index of random variable is put forward.By calculating the vertical deformation data of cross-faults in Sichuan-Yunnan area and the northern margin of Qinghai-Tibet block,and comparatively studying some practical earthquake examples, the results are obtained: the quantized index increases or decreases obviously before and after earthquake.
引文
1 周硕愚,等.地震短临前兆机理与断层形变前兆标志[J].地壳形变与地震,1993,13(增刊2):15~22.
1 Zhou Shuoyu,et al.The mechanism of seismic short-impend-ing precursory and the precursors signs of fault deformation[J].Crustal Deformation and Earthquake.1993,13(Sup.2):15-22.(in Chinese)
2 江在森,等.永登5.8级地震孕育发生过程中的断层形变与重力场动态图像特征[J].地震学报,1998,20(3):264~271.
2 Jiang Zaisen,et al.Dynamic pattern characteristics of fault deformation and gravity field in the development process of YongdengMs5.8earthquake[J].Acta Seismologica Sinica.1998,20(3):264-271.(in Chinese)
3 刘善华,等.强震孕育与断层形变异常形态及时空分布特征[J]大地测量与地球动力学,2004,24(4):15~22.
3 Liu Shanhua,et al.Form of fault deformation anomaly and time-space characteristics in development of stromg earth-quakes[J].Journal of Geodesy and Geodynamics,2004,24(4):15-22.(in Chinese)
4 张国民.地震预报与震灾预测(讲座)[J].地震地磁观测与研究,1996,17(3):21~56.
4 Zhang Guomin.Earthuake and its disaster prediction[J].Seismological and Geomagnetic Observation and Research,1996,17(3):21-56.(in Chinese)
5 张四新,等.地震前后垂直形变场动态演化的量化指标[J].大地测量与地球动力学,2004,24(3):35~39.
5 Zhang Sixin,et al.Quantized index of evolution of vertical deformation field before and after earthquake[J].Journal of Geodesy and Geodynamics,2004,24(4):15-22.(in Chi-nese)
6 石绍先,等.滇西北跨断层短基线群体异常与成组强震[J].西北地震学报,2004,26(2):147~153.
6 Shi Shaoxian,et al.Group anomaly of cross-fault short base-line measurement and grouped strong earthquakes in north-west Yunnan[J].Northwestern Seismological Journal,2004,26(2):147-153.(in Chinese)
7 郭良迁,等.张北6.2级地震的断层形变速率异常[J].地壳形变与地震,2001,21(1):79~84.
7 Guo liangqian,et al.Anomaly of concerned fault deformation rate related to Zhangbei earthquake of6.2[J].Crustal De-formation and Earthquake,2001,21(1):.79-84.(in Chi-nese)
8 张希,等.断层形变的应变强度比动态图像与震例综合研究[J].地壳形变与地震,2001,21(2):37~42.
8 Zhang Xi,et al.Comprehensive study on dynamic patterns of strain strength ratio of fault deformation and seismic exam-ples[J].Crustal Deformation and Earthquake,2001,21(2):37-42.(in Chinese)
1 Zhou Shuoyu,et al.The mechanism of seismic short-impend-ing precursory and the precursors signs of fault deformation[J].Crustal Deformation and Earthquake.1993,13(Sup.2):15-22.(in Chinese)
2 江在森,等.永登5.8级地震孕育发生过程中的断层形变与重力场动态图像特征[J].地震学报,1998,20(3):264~271.
2 Jiang Zaisen,et al.Dynamic pattern characteristics of fault deformation and gravity field in the development process of YongdengMs5.8earthquake[J].Acta Seismologica Sinica.1998,20(3):264-271.(in Chinese)
3 刘善华,等.强震孕育与断层形变异常形态及时空分布特征[J]大地测量与地球动力学,2004,24(4):15~22.
3 Liu Shanhua,et al.Form of fault deformation anomaly and time-space characteristics in development of stromg earth-quakes[J].Journal of Geodesy and Geodynamics,2004,24(4):15-22.(in Chinese)
4 张国民.地震预报与震灾预测(讲座)[J].地震地磁观测与研究,1996,17(3):21~56.
4 Zhang Guomin.Earthuake and its disaster prediction[J].Seismological and Geomagnetic Observation and Research,1996,17(3):21-56.(in Chinese)
5 张四新,等.地震前后垂直形变场动态演化的量化指标[J].大地测量与地球动力学,2004,24(3):35~39.
5 Zhang Sixin,et al.Quantized index of evolution of vertical deformation field before and after earthquake[J].Journal of Geodesy and Geodynamics,2004,24(4):15-22.(in Chi-nese)
6 石绍先,等.滇西北跨断层短基线群体异常与成组强震[J].西北地震学报,2004,26(2):147~153.
6 Shi Shaoxian,et al.Group anomaly of cross-fault short base-line measurement and grouped strong earthquakes in north-west Yunnan[J].Northwestern Seismological Journal,2004,26(2):147-153.(in Chinese)
7 郭良迁,等.张北6.2级地震的断层形变速率异常[J].地壳形变与地震,2001,21(1):79~84.
7 Guo liangqian,et al.Anomaly of concerned fault deformation rate related to Zhangbei earthquake of6.2[J].Crustal De-formation and Earthquake,2001,21(1):.79-84.(in Chi-nese)
8 张希,等.断层形变的应变强度比动态图像与震例综合研究[J].地壳形变与地震,2001,21(2):37~42.
8 Zhang Xi,et al.Comprehensive study on dynamic patterns of strain strength ratio of fault deformation and seismic exam-ples[J].Crustal Deformation and Earthquake,2001,21(2):37-42.(in Chinese)
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