摘要
在中国大陆，不同震源区过去多次特征地震之间时间间隔的变异系数一般大于０．３５，且在不同的震源区各不相同。以特征地震轮回的ｉ－ｆ－ｊ模式（闻学泽等，１９９４）为基础，将特征地震复发时间Ｔ表示成同一轮回事件ｉ至事件ｆｉ的时间差Ｔ＿ｉｆ的函数，并发展了估计“当前”轮回平均复发时间的方法。对任一震源区而言，用该方法估计的平均复发时间与过去特征地震时间间隔的表现行为无关。进一步得到Ｔ近似服从于对数正态分布ＬＮ（μｐ，σ２），其中，分布参数μｐ可由所研究轮回的时间差Ｔｉｆ估计，而参数σ≈０．２２６。这种复发时间的概率分布具有“通用分布”的性质。文中给出了应用该分布计算未来特征地震复发概率的公式。作为对发展方法的初步应用，计算了１０个震源区当前轮回的平均复发时间以及自１９９５年起未来１０，２０和３０年内复发特征地震的概率。
On the Chinese mainland, variation coefficients of the time intervals among characteristic earthquakes are different from one source to another, generally larger than 0. 35. Onthe basis of the i--f--j model of characteristic earthquake cycle (Wen et. al., 1994), the recurrence time T of characteristic earthquakes has been expressed as a function of the time--difference Ti f from the characteristic event i to the first gap--filling event f, at the same cycle.A method to estimate the average recurrence time of the 'present cycle' has developed. Forany source, the estimated average time by this method is independent of the behavior of theintervals between or among characteristic events in the P7st. Further, it has been obtainedthat T approximately obeys lognormal distribution LN (μp, σ2), of which, the parameterPp can be estimated by the the time-difference Ti f of the interested cycle, and the parameterσ≈0.226. This probabilistic distribution for recurrence time is of character of 'genericdistribution'. The formulations of calculating the recurrence probabilities of future characteristig earthquakes on the basis of the distribution have been given in this paper. As examexamples of preliminary application of the developed methods, the average recurrence intervalsof the present cycles and the probabilities of characteristic earthquake recurrences withinthe coming 10, 20 and 30 years at 10 sources have been calculated, taking the year of 1995as the beginning of the forecasting periods.
出处
《中国地震》
CSCD
北大核心
1994年第3期206-216,共11页
Earthquake Research in China
关键词
地震活动性
地震预报
中长期预报
Recurrence time, Present cycle, Lognormal distribution, Recurrence probability
