我国大陆及其邻区6级以上地震的“缺震事件”——一种大地震中期预测指标的分析研究

THE“EARTHQUAKE -ABSENT EVENTS”FOR THOSE EARTHQUAKES WITH MAGNITUDE OVER 6. 0 IN CHINESE CONTINENT AND THE ADJACENT AREA-AN ANALYTICAL INDEX OF MEDIUM TERM PREDICTION FOR LARGE EARTHQUAKES

在内陆强震活动的起伏中,6级以上地震的大范围长时间缺震,具有重要的意义。有的研究者已将其作为将发生7级地震前的标志之一。作者系统地清理了1897—1988年8月间中国大陆及其邻区6级以上地震“缺震事件”的始末,较多的震例表明,限定“缺震事件”起止的地震具有中期预报意义。它们在地震构造上的原因可能是代表区域最活跃的破裂,突然处于阻碍、闭锁状态,其持续时间大于10个月,再次发生6级以上地震为解锁,并随即出现新的一轮大地震活动。故可以作为一种大地震中期预测的指标。

The long time period for lack of large earthquakes (M≥6. 0)in a wide range in such a strong background of seismic activity is of great importance. Someone considered it as an omen of 7. 0 great earthquake occurrence. The initial and omega of the earthquakes with magnitude over 6. 0 in the 'earthquake - absent events'during 1897 - August, 1988 in China are systematically studied. It is shown out through many examples of earthquakes that determining the initial and end of the earthquakes in ' earthquake - absent events' has the significance in medium term earthquake prediction. The reason for lack of larger earthquakes in the most active fractural regions may be due to the sudden lock of the fault, which usually lasts for more than ten months and then gives relief in forms of large quake occurrence at last. A new circle of great seismic activity begins. Therefore, it can be used as an index of medium term prediction for future large earthquakes.