中国大陆西部前兆异常涨落与强震短期预测研究

统计了1998年以来西部六省区(云南、 四川、 青海、 甘肃、 宁夏、 新疆)前兆异常月频次, 探讨了异常数量的涨落与强震活动的关系。 结果表明, 大部分强震前强震所在省份及邻区的前兆异常数量有明显的持续增长现象, 临震时一般表现为异常回落至低值。 从时间上看, 异常增长的起始时间一般为震前3～4个月到震前7～8个月, 少量为震前14～18个月; 异常数量到达峰值的时间为震前1个月至震前10个月。 研究认为, 异常月频次峰值时间可以作为强震预测的中短期至短期指标。 研究还表明, 2001年昆仑山口西8.1级地震前, 除青海、 甘肃地区外, 云南、 四川的前兆异常也突出, 似乎显示了8.1级地震的孕育范围已影响到川滇地区。

Study on the relationship between fluctuation of anomalies in the Western China and short-term prediction of strong earthquakes

The relationship between fluctuation of anomalies in the western China and short-term prediction of strong earthquakes was studied on the basis of statistical result of monthly anomaly frequency in Yunnan, Sichuan, Qinghai, Gansu, Ningxia, and Xinjiang regions. The result shows that the number of the anomalies increases obviously and turns down before most of the strong earthquakes. The beginning time of the increase process is generally about three to eight months before the strong earthquake occurrence, sometimes fourteen to eighteen months. The peak of the increase process is about one to ten months before the strong earthquakes. The study shows that when the monthly frequency of anomalies reaches the peak value, the seismogenic process of strong earthquakes enters the medium-to short-term stage. The result also shows that the anomalies increase not only in Qinghai and Gansu regions but also in Yunnan and Sichuan regions before the West Kunlunshankou M8.1 earthquake, which might indicate that the seismogenic process of this giant earthquake has affected far away to Sichuan and Yunnan regions