摘要
依据1965年以来云南地区记录相对完整的108次5.0级以上地震序列资料,研究云南中强地震余震序列统计特征,探讨序列类型、余震震级、余震分布范围及间隔时间等与主震震级之间的关系。云南地区孤立型、主余型、多震型地震序列分别约占3.7%、63.0%及33.3%。5.0级以上主余型地震序列半年内发生的最大余震震级与主震震级总体呈正相关,但主震震级较低时相对离散。云南地区最大余震与主震距离空间分布具有分级的特点:当5.0≤主震震级M<6.5时,最大余震优势分布范围是0~20km;当主震震级M≥6.5时,最大余震优势分布范围是5~40km。在云南地区的主余型地震序列中有68%的最大余震发生在主震后10d内,84%发生在震后30d内,97%发生在震后90d内。多震型序列中第一大震与第二大震发生的时间间隔和震中距的分布规律与主余型地震序列基本一致。
The statistical characteristics of 108 moderate and strong M^5.0 earthquake sequences in Yun- nan province is analyzed including the sequence type, the magnitudes, the distribution range, the time in- terval, and the relationship between the main shock and the aftershocks. The results show that inYunnan area, earthquake sequence of isolation type, the main shock and after shock type, and multi-shock type ac- counts for about 3.7%, 63.0% and 3.7% respectively; to the earthquake sequences with main shock M≥ 5.0, the magnitude of their aftershocks is positively correlated with the magnitude of their main shock. If the main shock is 5.≤M〈6.5, the maximum aftershocks are in the range of 0--20 km from the epicenter of the main shock; if the main shock is M≥5.0, the maximum aftershocks are in the range of 5--40 km. of all the maximum aftershocks, 68% occurs within 10 days after its main shock, 84% occurs within 30 days, 97% occurs within 90 days. To main shock and aftershock type earthquake sequence and multi-shock type earthquake sequence, the distribution of time interval and epicenter distance between the maximum aftershock and second maximum aftershock are basically the same.
出处
《华北地震科学》
2015年第4期37-44,共8页
North China Earthquake Sciences
基金
云南省地震局传帮带项目:云南中强地震序列研究资助(C3-2014001)
关键词
余震序列
统计特征
云南地区
earthquake sequence
statistical characteristic
Yunnan area
