地震波动力学特征在宁蒗─盐源地区地震序列早期判断中的应用
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摘要
通过对宁蒗─盐源地区各类地震序列在３天和７天内地震波动力学特征的研究，表明该地区前震序列的地震在垂直分量上Ｐ波初动一致，且Ｐ、Ｓ波最大振幅比值稳定，呈过原点的直线，其振幅比值较低，而早期前震序列振幅比值较高。双震型地震序列出现两组初动，第一主震的余震振幅比不稳定，但第二主震的前震振幅比仍保持呈过原点的直线，利用地震特特征可望区分第一主震的余震和第二主震的前震。主余震地震序列的地震振幅比不稳定。应用地震波动力学特征作为地震序列的早期判断方法，可在３天和７天内对宁蒗─盐源地区的前震、双震型地震序列作出判断，在３天内对主余震序列作出判断。
When analyzing the seismic wave dynamical features in 3 and 7 days of each kind of seismic sequence in Ninglang-Yanyuan, we got to know that in this area,earthquakes in foreshock sequence showed a congruity in P wave onset at vertical component. Values of rnakimum amplitude ratio in P,S wave were stable and low, forcing a straight line through original point,while in the primary foreshock sequences,the values of amplitude ratio were high.There were two groups of onsets in double seismic type sequences,the aftershock amplitude ratio of first main shock were not steady, but the foreshock amplitude ratio of second main shock were still in form of a straight line through original point. The aftershock of first main shock and foreshock of second main shock can be distinguished by seismic wave characters.But the seismic amplitude ratio of major aftershock was not steady.When taking seisthec wave dynamical features as a primary diagnoses method,we can determine the foreshock,double shock seismic sequences in Ninglang-Yanyuan area in 3 or 7days, and determine the major aftershock seismic sequence in 3 days.
When analyzing the seismic wave dynamical features in 3 and 7 days of each kind of seismic sequence in Ninglang-Yanyuan, we got to know that in this area,earthquakes in foreshock sequence showed a congruity in P wave onset at vertical component. Values of rnakimum amplitude ratio in P,S wave were stable and low, forcing a straight line through original point,while in the primary foreshock sequences,the values of amplitude ratio were high.There were two groups of onsets in double seismic type sequences,the aftershock amplitude ratio of first main shock were not steady, but the foreshock amplitude ratio of second main shock were still in form of a straight line through original point. The aftershock of first main shock and foreshock of second main shock can be distinguished by seismic wave characters.But the seismic amplitude ratio of major aftershock was not steady.When taking seisthec wave dynamical features as a primary diagnoses method,we can determine the foreshock,double shock seismic sequences in Ninglang-Yanyuan area in 3 or 7days, and determine the major aftershock seismic sequence in 3 days.
引文
1陆远忠．等．地震预报的地震学方法．地震出版社，1985．2吴开统，等．地震序列概论．北京大学出版社，1990．3陈立德，等．震后趋势早期判断的初步研究．地震研究，1992，15（4）．4蔡静观．等．云南地区前震序列时空强特征和地震波特征．地震学报（增刊），1993．5蔡静观，等．云南地区强震前孕震系统的非线性阶段．地震研究，1993，16（4）．6程式，等．1976年11月7日四川省盐源6．7级地震．中国震例（1976～1980年）．地震出版社，1990．7蔡静观，等．双震型地震序列中第二主震的前震识别．待刊，1993．8马兰，等．影响断层带再活动的一些因素的实验研究．西北地震学报，1981，3（2）．
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