摘要
根据非线性动力学理论、运用概率论与数理统计方法,对非平衡地震发生系统的空间分布状态进行了研究。提出用空间变异系数δV判断涨落类型:凝聚集、群集、泊松型和均匀点阵分布。从整体观点综合应用各统计量即协方差μ11、非负量I(x,y)、联合信息熵H(x,y)、离散度σ和δV,对非平衡系统的群体空间自组织结构和临界状态的统计特征做了进一步的探讨。根据首都圈公元前231年～2003年M≥434地震活动及其和华北不同范围ML≥3.0地震活动涨落的统计分析认为,μ11≈0,I(x,y)>0,高H(x,y)值,低σ和δV值是强震和大震发生的自组织空间结构和临界现象的基本特征和必要条件。同时对地震空区、条带、前兆性震群及前震等前兆现象成因提出了新的观点和统计解释,并得出结论:仅当一个远离平衡态的系统(区域)有足够的随机性而又非泊松型涨落时,系统的突变(大震)是不可逆转的。
The spatial distribution of unbalanced seismic system is studied according to non-linear theory, method of probability and statistics. It is concluded that spatial variation coefficient δ_V can be used to judge the types of seismic activity; i.e. coherence, gathering, Poisson, uniform-lattice distribution. Self-organization structure of seismic colony and statistical characteristics of critical state are further discussed, using such statistical value as co-variance μ_(11), non-negative value I (x, y), information entropy, scattering degree σ and δ_V. Seismic events with M≥43/4 in Capital Circle Area and events with M_L≥(3.0) in different areas of North China are statistically analyzed. We think that μ_(11) ≈ 0, I(x, y)>0, high H(x, y) value, low and δ_V are the basic characteristics and essential condition of self-organization and critical state of strong and large earthquakes. A new viewpoint and statistic interpretation is supposed for the causes of seismic gap, seismic stripe, precursory swarm and foreshock. Conclusion is drawn that only when a seismic system far from balance state has enough randomness and non-Poisson fluctuation, then sudden change of the system, i.e. large earthquake occurrence will be irreversible.
出处
《地震》
CSCD
北大核心
2004年第4期1-15,共15页
Earthquake
基金
"十五"国家科研攻关项目(2004BA601B01 01 4)
关键词
涨落
变异系数
自组织
临界状态
统计学
地震活动
Fluctuation
Spatial variation coefficient
Self-origination
Critical state
Statistical characteristics
