川滇地区地震活动与地球自转速率变化之间的关系

利用川滇地区1962—2016年间发生的M_S≥6.0地震资料, 在去除余震的情况下, 分析了其发生与地球自转速率变化极值点之间的关系。 得到以下结果: 川滇地区M_S≥6.0地震的发生与地球自转速率变化极值点具有显著关系, 对于不同震级范围的地震, 其与不同周期的地球自转速率变化有关。 对于M_S≥7.0的地震, 有90%发生在地球自转速率季节性变化极值点前14天至后37天时间段内; 对于6.0≤M_S≤6.4的地震, 有80%发生在地球自转速率短周期变化极值点前68小时至后30小时的时间段内; 对于6.5≤M_S≤6.9的地震, 有87.5%发生在地球自转速率短周期变化极值点前36小时至后64小时的时间段内。 地震发生在特定时间段的显著性检验结果表明, 川滇地区M_S≥6.0地震与地球自转速率变化极值点的关系都可以在α=0.05的显著性水平下通过显著性检验。 这个结果表明, 在地球自转速率发生转折的期间容易触发地震, 对川滇地区地震发生时间预测具有参考意义。

Occurrence of Earthquakes in the Sichuan-Yunnan Region of China and the Velocity Variation of the Earth Rotation

Data of earthquakes with magnitude 6.0 occurring between 1962 and 2016 in Sichuan—Yunnan area is used to analyze the relationship between the occurrence of these events with their aftershocks excluded and the variation of velocity of the earth's rotation. The results obtained are as follows: there exists an obvious relationship between the occurrence of earthquakes with magnitude 6.0 occurring in the study area and the extreme point of variation of velocity of the earth rotation. For earthquakes within different magnitude spans, their occurrences are significantly associated with the extreme point of the different periodic variation of velocity of the earth rotation. It have be found that 90% earthquakes with M_S7.0 occurred during a period of time from 14 days before and 37 days after the extreme point of the seasonal variation of velocity of the earth rotation, 80% earthquakes with 6.0 M_S6.4 occurred during a period of time from 68 hours before and 30 hours after the extreme point of the short periodic variation of velocity of the earth rotation, and 87.5% earthquakes with 6.5 M_S6.9 occurred during a period of time from 36 hours before and 64 hours after the extreme point of the short periodic variation of velocity of the earth rotation. By statistical significance test, the above results have passed Z test at 5% level. It shows that earthquakes with magnitude 6.0 in the Sichuan—Yunnan area of China are prone to be caused by the turning changes of velocity of the earth rotation, which could be of some reference significance to predict the occurring time of earthquakes in the Sichuan—Yunnan region of China.