百年来中国大陆强震活动的微动态分期及其空间分布

分析了近百年来中国大陆强震的时间与空间分布。强震活动具有在时间上的起伏特征与空间上集中分布于主体地区的特征。综合考虑时间、空间的分布特征的动态变化 ,进一步阐明了微动态期划分的意义 ,并且与活动 -平静期进行了对比。中国及其邻区大陆强震的个体行为具有丛集性。近百年来存在一种大约 13a的阶段 ,反映了大范围的地震能量积累的起伏发展过程。与时间轴上的相对高潮期相对应 ,各期存在 1个地震活动主体地区与另 1个次活动区 ,2个大震活动区的相对位置往往分别处于青藏高原的两侧。相当部分的强震孕育是在原有孕震区继续进行的 ,而多数强震的孕育是在原有区域外进行的。活跃期与平静期的划分对理解时间分布的不均匀性是有意义的 ,然而活动期的长短不一 ,强度不同 ,活动期内也有起伏。从强震活动的孕育过程看 ,微动态期的划分更有利于对强震空间分布的预测

TEMPORAL AND SPATIAL DISTRIBUTIONS OF STRONG EARTHQUAKES IN CHINA S CONTINENT IN THE PAST CENTURY

The temporal and spatial distributions of strong earthquakes in the past century in China's continent are analyzed in this paper. Both the temporal and spatial distributions of strong earthquakes display a clustering feature. The activity of strong earthquakes is undulate and clustered in the major region in certain period. Based on both temporal and spatial distributions of strong earthquakes in China's continent, a synthetic division of dynamic phases is carried out. The activities of strong earthquakes have approximately 13 year's periods in China's continent in the past century. In each period, most strong earthquakes cluster in a major region and a minor region, corresponding to a wave of energy release on the time axis. The major region and minor region are located on opposite sides of the Tibet Plateau. Quite a portion of strong earthquakes is developed in the original seismogenic area, but most events are developed outside the last major or minor regions. This may imply the fluctuation of energy accumulation in large scale area. The division of active and quiescent periods of seismic activity is of benefit to understanding the undulation of energy release. However, both the length of active period and the intensity of energy vary with time, while within the active period the seismic activity is uneven. Comparatively, the division of dynamic phases is more advantageous to strong earthquake prediction.