内、外动力作用与丽江7.0级地震的发生
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摘要
为了从动力学角度研究1996年2月3日丽江7．0级地震的孕育及发生过程，从分析该地震所处的滇西北大区的构造动力背景入手，揭示了近年来该地区中强、中小地震的异常活动持征和丽江附近形成的空区的孕震意义。尔后通过对多种外力的时空动态跟踪分析，发现震前中期尺度的涝旱剧变、短期尺度的气压突变及临震尺度的引潮力增大是促使孕震介质渐趋不稳定直至破裂发震的重要因素。
A Ms 7. 0 earthquake occurred in Lijiang on Feb. 3, 1996. In order to study its process ofgenesis and occurrence from the angle of dynamics,the tectonic dynamic background in the1arge region of Northwestern Yunnan where the Lijiang earthquake occurred is analyzed,andthe anomalous characteristics of the moderately, lightly strong.earthquake activity in thisarea and the seismogcnic meaning of thc gap that formed near Lijiang are revealed. Throughtracing and analyzing the time-space changes of many kinds of external forces, it is foundthat violent drought-waterlogging change of medium term, sudden air pressure change ofshort-term and impending-earthquake increase of tide-generating force are the principle fac-tors that cause seismogenic medium gradually to become unstable and earthquake t0 happen.
A Ms 7. 0 earthquake occurred in Lijiang on Feb. 3, 1996. In order to study its process ofgenesis and occurrence from the angle of dynamics,the tectonic dynamic background in the1arge region of Northwestern Yunnan where the Lijiang earthquake occurred is analyzed,andthe anomalous characteristics of the moderately, lightly strong.earthquake activity in thisarea and the seismogcnic meaning of thc gap that formed near Lijiang are revealed. Throughtracing and analyzing the time-space changes of many kinds of external forces, it is foundthat violent drought-waterlogging change of medium term, sudden air pressure change ofshort-term and impending-earthquake increase of tide-generating force are the principle fac-tors that cause seismogenic medium gradually to become unstable and earthquake t0 happen.
引文
1赵洪声,刘祖荫.云南地震预报系统论.北京:地震出版社.1993.
2泰保燕.大震前复杂震源系统的非线性阶段和大震预报(一).西北地震学报,1986,8(4):1～8
2泰保燕.大震前复杂震源系统的非线性阶段和大震预报(一).西北地震学报,1986,8(4):1～8
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